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Chapter 1: Programming With Visual C++ 2010

  • What the principal components of Visual C++ 2010 are

  • What the .NET Framework consists of and the advantages it offers

  • What solutions and projects are and how you create them

  • About console programs

  • How to create and edit a program

  • How to compile, link, and execute C++ console programs

  • How to create and execute basic Windows programs

Windows programming isn’t difficult. Microsoft Visual C++ 2010 makes it remarkably easy, as you’ll see throughout the course of this book. There’s just one obstacle in your path: Before you get to the specifics of Windows programming, you have to be thoroughly familiar with the capabilities of the C++ programming language, particularly the object-oriented aspects of the language. Object-oriented techniques are central to the effectiveness of all the tools provided by Visual C++ 2010 for Windows programming, so it’s essential that you gain a good understanding of them. That’s exactly what this book provides.

This chapter gives you an overview of the essential concepts involved in programming applications in C++. You’ll take a rapid tour of the integrated development environment (IDE) that comes with Visual C++ 2010. The IDE is straightforward and generally intuitive in its operation, so you’ll be able to pick up most of it as you go along. The best way to get familiar with it is to work through the process of creating, compiling, and executing a simple program.

So power up your PC, start Windows, load the mighty Visual C++ 2010, and begin your journey.

The .NET Framework is a central concept in Visual C++ 2010 as well as in all the other .NET development products from Microsoft. The .NET Framework consists of two elements: the Common Language Runtime (CLR) in which your application executes, and a set of libraries called the .NET Framework class libraries. The .NET Framework class libraries provide the functional support your code will need when executing with the CLR, regardless of the programming language used, so .NET programs written in C++, C#, or any of the other languages that support the .NET Framework all use the same .NET libraries.

There are two fundamentally different kinds of C++ applications you can develop with Visual C++ 2010. You can write applications that natively execute on your computer. These applications will be referred to as native C++ programs; you write native C++ programs in the version of C++ defined by the ISO/IEC (International Standards Organization/International Electrotechnical Commision) language standard. You can also write applications to run under the control of the CLR in an extended version of C++ called C++/CLI. These programs will be referred to as CLR programs, or C++/CLI programs.

The .NET Framework is not strictly part of Visual C++ 2010 but rather a component of the Windows operating system that makes it easier to build software applications and Web services. The .NET Framework offers substantial advantages in code reliability and security, as well as the ability to integrate your C++ code with code written in over 20 other programming languages that target the .NET Framework. A slight disadvantage of targeting the .NET Framework is that there is a small performance penalty compared to native code, but you won’t notice this in the majority of circumstances.

The Common Language Runtime (CLR) is a standardized environment for the execution of programs written in a wide range of high-level languages including Visual Basic, C#, and of course C++. The specification of the CLR is now embodied in the European Computer Manufacturers Association (ECMA) standard for the Common Language Infrastructure (CLI), the ECMA-335, and also in the equivalent ISO standard, ISO/IEC 23271, so the CLR is an implementation of this standard. You can see why C++ for the CLR is referred to as C++/CLI — it’s C++ for the Common Language Infrastructure, so you are likely to see C++/CLI compilers on other operating systems that implement the CLI.

NoteNote

Information about all ECMA standards is available from www.ecma-international.org, and ECMA-335 is currently available as a free download.

The CLI is essentially a specification for a virtual machine environment that enables applications written in diverse high-level programming languages to be executed in different system environments without the original source code’s being changed or replicated. The CLI specifies a standard intermediate language for the virtual machine to which the high-level language source code is compiled. With the .NET Framework, this intermediate language is referred to as Microsoft Intermediate Language (MSIL). Code in the intermediate language is ultimately mapped to machine code by a just-in-time (JIT) compiler when you execute a program. Of course, code in the CLI intermediate language can be executed within any other environment that has a CLI implementation.

The CLI also defines a common set of data types called the Common Type System (CTS) that should be used for programs written in any programming language targeting a CLI implementation. The CTS specifies how data types are used within the CLR and includes a set of predefined types. You may also define your own data types, and these must be defined in a particular way to be consistent with the CLR, as you’ll see. Having a standardized type system for representing data allows components written in different programming languages to handle data in a uniform way and makes it possible to integrate components written in different languages into a single application.

Data security and program reliability is greatly enhanced by the CLR, in part because dynamic memory allocation and release for data is fully automatic, but also because the MSIL code for a program is comprehensively checked and validated before the program executes. The CLR is just one implementation of the CLI specification that executes under Microsoft Windows on a PC; there will undoubtedly be other implementations of the CLI for other operating system environments and hardware platforms. You’ll sometimes find that the terms CLI and CLR are used interchangeably, although it should be evident that they are not the same thing. The CLI is a standard specification; the CLR is Microsoft’s implementation of the CLI.

You have tremendous flexibility in the types of applications and program components that you can develop with Visual C++ 2010. As noted earlier in this chapter, you have two basic options for Windows applications: You can write code that executes with the CLR, and you can also write code that compiles directly to machine code and thus executes natively. For window-based applications targeting the CLR, you use Windows Forms as the base for the GUI provided by the .NET Framework libraries. Using Windows Forms enables rapid GUI development because you assemble the GUI graphically from standard components and have the code generated completely automatically. You then just need to customize the code that has been generated to provide the functionality that you require.

For natively executing code, you have several ways to go. One possibility is to use the Microsoft Foundation Classes (MFC) for programming the graphical user interface for your Windows application. The MFC encapsulates the Windows operating system Application Programming Interface (API) for GUI creation and control and greatly eases the process of program development. The Windows API originated long before the C++ language arrived on the scene, so it has none of the object-oriented characteristics that would be expected if it were written today; however, you are not obliged to use the MFC. If you want the ultimate in performance, you can write your C++ code to access the Windows API directly.

C++ code that executes with the CLR is described as managed C++ because data and code are managed by the CLR. In CLR programs, the release of memory that you have allocated dynamically for storing data is taken care of automatically, thus eliminating a common source of error in native C++ applications. C++ code that executes outside the CLR is sometimes described by Microsoft as unmanaged C++ because the CLR is not involved in its execution. With unmanaged C++ you must take care of all aspects of allocating and releasing memory during execution of your program yourself, and also forego the enhanced security provided by the CLR. You’ll also see unmanaged C++ referred to as native C++ because it compiles directly to native machine code.

Figure 1-1 shows the basic options you have for developing C++ applications.

Figure 1-1

Referenced Screen

Figure 1-1 is not the whole story. An application can consist partly of managed C++ and partly of native C++, so you are not obliged to stick to one environment or the other. Of course, you do lose out somewhat by mixing code, so you would choose to follow this approach only when necessary, such as when you want to convert an existing native C++ application to run with the CLR. You obviously won’t get the benefits inherent in managed C++ in the native C++ code, and there can also be appreciable overhead involved in communications between the managed and unmanaged code components. The ability to mix managed and unmanaged code can be invaluable, however, when you need to develop or extend existing unmanaged code but also want to obtain the advantages of using the CLR. Of course, for new applications you should decide at the outset whether you want to create a managed C++ application or a native C++ application.

There are always two basic aspects to interactive applications executing under Windows: You need code to create the graphical user interface (GUI) with which the user interacts, and you need code to process these interactions to provide the functionality of the application. Visual C++ 2010 provides you with a great deal of assistance in both aspects of Windows application development. As you’ll see later in this chapter, you can create a working Windows program with a GUI without writing any code yourself at all. All the basic code to create the GUI can be generated automatically by Visual C++ 2010; however, it’s essential to understand how this automatically generated code works because you need to extend and modify it to make it do what you want, and to do that you need a comprehensive understanding of C++.

For this reason you’ll first learn C++ — both the native C++ and C++/CLI versions of the language — without getting involved in Windows programming considerations. After you’re comfortable with C++ you’ll learn how to develop fully-fledged Windows applications using native C++ and C++/CLI. This means that while you are learning C++, you’ll be working with programs that involve only command line input and output. By sticking to this rather limited input and output capability, you’ll be able to concentrate on the specifics of how the C++ language works and avoid the inevitable complications involved in GUI building and control. After you become comfortable with C++ you’ll find that it’s an easy and natural progression to applying C++ to the development of Windows application programs.

Learning C++

Visual C++ 2010 fully supports two versions of C++, defined by two separate standards:

  • The ISO/IEC C++ standard is for implementing native applications — unmanaged C++. This version of C++ is supported on the majority of computer platforms.

  • The C++/CLI standard is designed specifically for writing programs that target the CLR and is an extension of the ISO/IEC C++.

Chapters 2 through 9 of this book teach you the C++ language. Because C++/CLI is an extension of ISO/IEC C++, the first part of each chapter introduces elements of the ISO/IEC C++ language; the second part explains the additional features that C++/CLI introduces.

Writing programs in C++/CLI enables you to take full advantage of the capabilities of the .NET Framework, something that is not possible with programs written in ISO/IEC C++. Although C++/CLI is an extension of ISO/IEC C++, to be able to execute your program fully with the CLR means that it must conform to the requirements of the CLR. This implies that there are some features of ISO/IEC C++ that you cannot use in your CLR programs. One example of this that you might deduce from what I have said up to now is that the dynamic memory allocation and release facilities offered by ISO/IEC C++ are not compatible with the CLR; you must use the CLR mechanism for memory management, and this implies that you must use C++/CLI classes, not native C++ classes.

The C++ Standards

At the time of writing, the currently approved C++ language standard is defined by the document ISO/IEC 14882:1998, published by the International Organization for Standardization (ISO). This is the well-established version of C++ that has been around since 1998 and is supported by compilers on the majority of computer hardware platforms and operating systems. There is a new standard for C++ in draft form that is expected to be approved in the near future. Visual C++ 2010 already supports several of the new language capabilities offered by this new standard, and these are described in this book.

Programs that you write in standard C++ can be ported from one system environment to another reasonably easily, although the library functions that a program uses — particularly those related to building a graphical user interface — are a major determinant of how easy or difficult it will be. ISO/IEC standard C++ is the first choice of many professional program developers because it is so widely supported, and because it is one of the most powerful programming languages available today.

C++/CLI is a version of C++ that extends the ISO/IEC standard for C++ to better support the Common Language Infrastructure (CLI) defined by the standard ECMA-355. The C++/CLI language specification is defined by the standard ECMA-372 and is available for download from the ECMA web site. This standard was developed from an initial technical specification that was produced by Microsoft to support the execution of C++ programs with the .NET Framework. Thus, both the CLI and C++/CLI were originated by Microsoft in support of the .NET Framework. Of course, standardizing the CLI and C++/CLI greatly increases the likelihood of implementation in environments other than Windows. It’s important to appreciate that although C++/CLI is an extension of ISO/IEC C++, there are features of ISO/IEC C++ that you must not use when you want your program to execute fully under the control of the CLR. You’ll learn what these are as you progress through the book.

The CLR offers substantial advantages over the native environment. If you target your C++ programs at the CLR, they will be more secure and not prone to the potential errors you can make when using the full power of ISO/IEC C++. The CLR also removes the incompatibilities introduced by various high-level languages by standardizing the target environment to which they are compiled, and thus permits modules written in C++ to be combined with modules written in other languages, such as C# or Visual Basic.

Attributes

Attributes are an advanced feature of programming with C++/CLI that enable you to add descriptive declarations to your code. At the simplest level, you can use attributes to annotate particular programming elements in your program, but there’s more to attributes than just additional descriptive data. Attributes can affect how your code behaves at run time by modifying the way the code is compiled or by causing extra code to be generated that supports additional capabilities. A range of standard attributes is available for C++/CLI, and it is also possible to create your own.

A detailed discussion of attributes is beyond the scope of this book, but I mention them here because you will make use of attributes in one or two places in the book, particularly in Chapter 19, where you learn how to write objects to a file.

Console Applications

As well as developing Windows applications, Visual C++ 2010 also enables you to write, compile, and test C++ programs that have none of the baggage required for Windows programs — that is, applications that are essentially character-based, command-line programs. These programs are called console applications in Visual C++ 2010 because you communicate with them through the keyboard and the screen in character mode.

When you write console applications it might seem as if you are being sidetracked from the main objective of Windows programming, but when it comes to learning C++ (which you do need to do before embarking on Windows-specific programming) it’s the best way to proceed. There’s a lot of code in even a simple Windows program, and it’s very important not to be distracted by the complexities of Windows when learning the ins and outs of C++. Therefore, in the early chapters of the book, which are concerned with how C++ works, you’ll spend time walking with a few lightweight console applications before you get to run with the heavyweight sacks of code in the world of Windows.

While you’re learning C++, you’ll be able to concentrate on the language features without worrying about the environment in which you’re operating. With the console applications that you’ll write, you have only a text interface, but this will be quite sufficient for understanding all of C++ because there’s no graphical capability within the definition of the language. Naturally, I will provide extensive coverage of graphical user interface programming when you come to write programs specifically for Windows using Microsoft Foundation Classes (MFC) in native C++ applications, and Windows Forms with the CLR.

There are two distinct kinds of console applications, and you’ll be using both.

  • Win32 console applications compile to native code. You’ll be using these to try out the capabilities of ISO/IEC C++.

  • CLR console applications target the CLR. You’ll be using these when you are working with the features of C++/CLI.

Windows Programming Concepts

The project creation facilities provided with Visual C++ 2010 can generate skeleton code for a wide variety of native C++ application programs automatically, including basic Windows programs. For Windows applications that you develop for the CLR you get even more automatic code generation. You can create complete applications using Windows Forms that require only a small amount of customized code to be written by you, and some that require no additional code at all. Creating a project is the starting point for all applications and components that you develop with Visual C++ 2010, and to get a flavor of how this works you’ll look at the mechanics of creating some examples, including an outline Windows program, later in this chapter.

A Windows program, whether a native C++ program or a program written for the CLR, has a different structure from that of the typical console program you execute from the command line, and it’s more complicated. In a console program you can get input from the keyboard and write output back to the command line directly, whereas a Windows program can access the input and output facilities of the computer only by way of functions supplied by the host environment; no direct access to the hardware resources is permitted. Because several programs can be active at one time under Windows, Windows has to determine which application a given raw input, such as a mouse click or the pressing of a key on the keyboard, is destined for, and signal the program concerned accordingly. Thus, the Windows operating system has primary control of all communications with the user.

The nature of the interface between a user and a Windows application is such that a wide range of different inputs is usually possible at any given time. A user may select any of a number of menu options, click a toolbar button, or click the mouse somewhere in the application window. A well-designed Windows application has to be prepared to deal with any of the possible types of input at any time because there is no way of knowing in advance which type of input is going to occur. These user actions are received by the operating system in the first instance, and are all regarded by Windows as events. An event that originates with the user interface for your application will typically result in a particular piece of your program code being executed. How program execution proceeds is therefore determined by the sequence of user actions. Programs that operate in this way are referred to as event-driven programs, and are different from traditional procedural programs that have a single order of execution. Input to a procedural program is controlled by the program code and can occur only when the program permits it; therefore, a Windows program consists primarily of pieces of code that respond to events caused by the action of the user, or by Windows itself. This sort of program structure is illustrated in Figure 1-2.

Figure 1-2

Referenced Screen

Each square block in Figure 1-2 represents a piece of code written specifically to deal with a particular event. The program may appear to be somewhat fragmented because of the number of disjointed blocks of code, but the primary factor welding the program into a whole is the Windows operating system itself. You can think of your program as customizing Windows to provide a particular set of capabilities.

Of course, the modules servicing various external events, such as the selection of a menu or a mouse click, all typically have access to a common set of application-specific data in a particular program. This application data contains information that relates to what the program is about — for example, blocks of text recording scoring records for a player in a program aimed at tracking how your baseball team is doing — as well as information about some of the events that have occurred during execution of the program. This shared collection of data allows various parts of the program that look independent to communicate and operate in a coordinated and integrated fashion. I will go into this in much more detail later in the book.

Even an elementary Windows program involves several lines of code, and with Windows programs generated by the application wizards that come with Visual C++ 2010, “several” turns out to be “many.” To simplify the process of understanding how C++ works, you need a context that is as uncomplicated as possible. Fortunately, Visual C++ 2010 comes with an environment that is ready-made for the purpose.

The integrated development environment (IDE) that comes with Visual C++ 2010 is a completely self-contained environment for creating, compiling, linking, and testing your C++ programs. It also happens to be a great environment in which to learn C++ (particularly when combined with a great book).

Visual C++ 2010 incorporates a range of fully integrated tools designed to make the whole process of writing C++ programs easy. You will see something of these in this chapter, but rather than grind through a boring litany of features and options in the abstract, you can first take a look at the basics to get a view of how the IDE works, and then pick up the rest in context as you go along.

The fundamental parts of Visual C++ 2010, provided as part of the IDE, are the editor, the compiler, the linker, and the libraries. These are the basic tools that are essential to writing and executing a C++ program. Their functions are as follows.

The Editor

The editor provides an interactive environment in which to create and edit C++ source code. As well as the usual facilities, such as cut and paste, which you are certainly already familiar with, the editor also provides color cues to differentiate between various language elements. The editor automatically recognizes fundamental words in the C++ language and assigns a color to them according to what they are. This not only helps to make your code more readable, but also provides a clear indicator of when you make errors in keying such words.

The Compiler

The compiler converts your source code into object code, and detects and reports errors in the compilation process. The compiler can detect a wide range of errors caused by invalid or unrecognized program code, as well as structural errors, such as parts of a program that can never be executed. The object code output from the compiler is stored in files called object files that have names with the extension .obj.

The Linker

The linker combines the various modules generated by the compiler from source code files, adds required code modules from program libraries supplied as part of C++, and welds everything into an executable whole. The linker can also detect and report errors — for example, if part of your program is missing, or a nonexistent library component is referenced.

The Libraries

A library is simply a collection of prewritten routines that supports and extends the C++ language by providing standard professionally-produced code units that you can incorporate into your programs to carry out common operations. The operations implemented by routines in the various libraries provided by Visual C++ 2010 greatly enhance productivity by saving you the effort of writing and testing the code for such operations yourself. I have already mentioned the .NET Framework library, and there are a number of others — too many to enumerate here — but I’ll identify the most important ones.

The Standard C++ Library defines a basic set of routines common to all ISO/IEC C++ compilers. It contains a wide range of routines, including numerical functions, such as the calculation of square roots and the evaluation of trigonometrical functions; character- and string-processing routines, such as the classification of characters and the comparison of character strings; and many others. You’ll get to know quite a number of these as you develop your knowledge of ISO/IEC C++. There are also libraries that support the C++/CLI extensions to ISO/IEC C++.

Native window-based applications are supported by a library called the Microsoft Foundation Classes (MFC). The MFC greatly reduces the effort needed to build the graphical user interface for an application. (You’ll see a lot more of the MFC when you finish exploring the nuances of the C++ language.) Another library contains a set of facilities called Windows Forms, which are roughly the equivalent of the MFC for windows-based applications executed with the .NET Framework. You’ll be seeing how you make use of Windows Forms to develop applications, too.

All program development and execution in this book is performed from within the IDE. When you start Visual C++ 2010 you’ll notice an application window similar to that shown in Figure 1-3.

Figure 1-3

Referenced Screen

The pane to the left in Figure 1-3 is the Solution Explorer window, the top right pane presently showing the Start page is the Editor window, and the tab visible in the pane at the bottom is the Output window. The Solution Explorer window enables you to navigate through your program files and display their contents in the Editor window, and to add new files to your program. The Solution Explorer window has an additional tab (only three are shown in Figure 1-3) that displays the Resource View for your application, and you can select which tabs are to be displayed from the View menu. The Editor window is where you enter and modify source code and other components of your application. The Output window displays the output from build operations in which a project is compiled and linked. You can choose to display other windows by selecting from the View menu.

Note that a window can generally be undocked from its position in the Visual C++ application window. Just right-click the title bar of the window you want to undock and select Float from the pop-up menu. In general, I will show windows in their undocked state in the book. You can restore a window to its docked state by right-clicking its title bar and selecting Dock from the pop-up.

Toolbar Options

You can choose which toolbars are displayed in your Visual C++ window by right-clicking in the toolbar area. The range of toolbars in the list depends on which edition of Visual C++ 2010 you have installed. A pop-up menu with a list of toolbars (Figure 1-4) appears, and the toolbars currently displayed have checkmarks alongside them.

This is where you decide which toolbars are visible at any one time. You can make your set of toolbars the same as those shown in Figure 1-3 by making sure the Build, Class Designer, Debug, Standard, and View Designer menu items are checked. Clicking a toolbar in the list checks it if it is unchecked, and results in its being displayed; clicking a toolbar that is checked unchecks it and hides the toolbar.

You don’t need to clutter up the application window with all the toolbars you think you might need at some time. Some toolbars appear automatically when required, so you’ll probably find that the default toolbar selections are perfectly adequate most of the time. As you develop your applications, from time to time you might think it would be more convenient to have access to toolbars that aren’t displayed. You can change the set of visible toolbars whenever it suits you by right-clicking in the toolbar area and choosing from the context menu.

Figure 1-4

Referenced Screen
NoteNote

As in many other Windows applications, the toolbars that make up Visual C++ 2010 come complete with tooltips. Just let the mouse pointer linger over a toolbar button for a second or two, and a white label will display the function of that button.

Dockable Toolbars

A dockable toolbar is one that you can move around to position it at a convenient place in the window. You can arrange for any of the toolbars to be docked at any of the four sides of the application window. If you right-click in the toolbar area and select Customize from the pop-up, the Customize dialog will be displayed. You can choose where a particular toolbar is docked by selecting it and clicking the Modify Selection button. You can then choose from the drop-down list to dock the toolbar where you want. Figure 1-5 shows how the dialog looks after the user selects the Build toolbar on the left and clicks the Modify Selection button.

Figure 1-5

Referenced Screen

You’ll recognize many of the toolbar icons that Visual C++ 2010 uses from other Windows applications, but you may not appreciate exactly what these icons do in the context of Visual C++, so I’ll describe them as we use them.

Because you’ll use a new project for every program you develop, looking at what exactly a project is and understanding how the mechanism for defining a project works is a good place to start finding out about Visual C++ 2010.

Documentation

There will be plenty of occasions when you’ll want to find out more information about Visual C++ 2010 and its features and options. Press Ctrl+Alt+F1 to access the product documentation. The Help menu also provides various routes into the documentation, as well as access to program samples and technical support.

Projects and Solutions

A project is a container for all the things that make up a program of some kind — it might be a console program, a window-based program, or some other kind of program — and it usually consists of one or more source files containing your code, plus possibly other files containing auxiliary data. All the files for a project are stored in the project folder; detailed information about the project is stored in an XML file with the extension .vcxproj, also in the project folder. The project folder also contains other folders that are used to store the output from compiling and linking your project.

The idea of a solution is expressed by its name, in that it is a mechanism for bringing together all the programs and other resources that represent a solution to a particular data-processing problem. For example, a distributed order-entry system for a business operation might be composed of several different programs that could each be developed as a project within a single solution; therefore, a solution is a folder in which all the information relating to one or more projects is stored, and one or more project folders are subfolders of the solution folder. Information about the projects in a solution is stored in two files with the extensions .sln and .suo, respectively. When you create a project a new solution is created automatically unless you elect to add the project to an existing solution.

When you create a project along with a solution, you can add further projects to the same solution. You can add any kind of project to an existing solution, but you will usually add only a project related in some way to the existing project, or projects, in the solution. Generally, unless you have a good reason to do otherwise, each of your projects should have its own solution. Each example you create with this book will be a single project within its own solution.

Defining a Project

The first step in writing a Visual C++ 2010 program is to create a project for it using the File | New | Project menu option from the main menu or by pressing Ctrl+Shift+N; you can also simply click New Project . . . on the Start page. As well as containing files that define all the code and any other data that makes up your program, the project XML file in the project folder also records the Visual C++ 2010 options you’re using.

That’s enough introductory stuff for the moment. It’s time to get your hands dirty.

Try it Out: Creating a Project for a Win32 Console Application

You’ll now take a look at creating a project for a console application. First, select File | New | Project or use one of the other possibilities mentioned earlier to bring up the New Project dialog box, as shown in Figure 1-6.

Figure 1-6

Referenced Screen

The left pane in the New Project dialog box displays the types of projects you can create; in this case, click Win32. This also identifies an application wizard that creates the initial contents for the project. The right pane displays a list of templates available for the project type you have selected in the left pane. The template you select is used by the application wizard in creating the files that make up the project. In the next dialog box you have an opportunity to customize the files that are created when you click the OK button in this dialog box. For most of the type/template options, a basic set of program source modules is created automatically.

You can now enter a suitable name for your project by typing into the “Name:” edit box — for example, you could call this one Ex1_01, or you can choose your own project name. Visual C++ 2010 supports long file names, so you have a lot of flexibility. The name of the solution folder appears in the bottom edit box and, by default, the solution folder has the same name as the project. You can change this if you want. The dialog box also enables you to modify the location for the solution that contains your project — this appears in the “Location:” edit box. If you simply enter a name for your project, the solution folder is automatically set to a folder with that name, with the path shown in the “Location:” edit box. By default the solution folder is created for you, if it doesn’t already exist. If you want to specify a different path for the solution folder, just enter it in the “Location:” edit box. Alternatively, you can use the Browse button to select another path for your solution. Clicking OK displays the Win32 Application Wizard dialog box shown in Figure 1-7.

Figure 1-7

Referenced Screen

This dialog box explains the settings currently in effect. If you click the Finish button the wizard creates all the project files based on the settings in this box. In this case, you can click Application Settings on the left to display the Application Settings page of the wizard, shown in Figure 1-8.

Figure 1-8

Referenced Screen

The Application Settings page enables you to choose options that you want to apply to the project. Here, you can leave things as they are and click Finish. The application wizard then creates the project with all the default files.

The project folder will have the name that you supplied as the project name and will hold all the files making up the project definition. If you didn’t change it, the solution folder has the same name as the project folder and contains the project folder plus the files defining the contents of the solution. If you use Windows Explorer to inspect the contents of the solution folder, you’ll see that it contains four files:

  • A file with the extension .sln that records information about the projects in the solution.

  • A file with the extension .suo in which user options that apply to the solution will be recorded.

  • A file with the extension .sdf that records data about Intellisense for the solution. Intellisense is the facility that provides auto-completion and prompts you for code in the Editor window as you enter it.

  • A file with the extension .opensdf that records information about the state of the project. This file exists only while the project is open.

If you use Windows Explorer to look in the project folder, you will see that there are eight files initially, including a file with the name ReadMe.txt that contains a summary of the contents of the files that have been created for the project. The project you have created will automatically open in Visual C++ 2010 with the Solution Explorer pane, as in Figure 1-9.

Figure 1-9

Referenced Screen

The Solution Explorer pane presents a view of all the projects in the current solution and the files they contain — here, of course, there is just one project. You can display the contents of any file as an additional tab in the Editor pane just by double-clicking the name in the Solution Explorer tab. In the Editor pane, you can switch instantly to any of the files that have been displayed just by clicking on the appropriate tab.

The Class View tab displays the classes defined in your project and also shows the contents of each class. You don’t have any classes in this application, so the view is empty. When I discuss classes you will see that you can use the Class View tab to move around the code relating to the definition and implementation of all your application classes quickly and easily.

The Property Manager tab shows the properties that have been set for the Debug and Release versions of your project. I’ll explain these versions a little later in this chapter. You can change any of the properties shown by right-clicking a property and selecting Properties from the context menu; this displays a dialog box where you can set the project property. You can also press Alt+F7 to display the properties dialog box at any time. I’ll discuss this in more detail when we go into the Debug and Release versions of a program.

You can display the Resource View tab by selecting from the View menu or by pressing Ctrl+Shift+E. The Resource View shows the dialog boxes, icons, menus, toolbars, and other resources used by the program. Because this is a console program, no resources are used; however, when you start writing Windows applications, you’ll see a lot of things here. Through this tab you can edit or add to the resources available to the project.

As with most elements of the Visual C++ 2010 IDE, the Solution Explorer and other tabs provide context-sensitive pop-up menus when you right-click items displayed in the tab, and in some cases when you right-click in the empty space in the tab, too. If you find that the Solution Explorer pane gets in your way when you’re writing code, you can hide it by clicking the Autohide icon. To redisplay it, click the Name tab on the left of the IDE window.

Modifying the Source Code

The application wizard generates a complete Win32 console program that you can compile and execute. Unfortunately, the program doesn’t do anything as it stands, so to make it a little more interesting you need to change it. If it is not already visible in the Editor pane, double-click Ex1_01.cpp in the Solution Explorer pane. This is the main source file for the program that the application wizard generated, and it looks like what is shown in Figure 1-10.

Figure 1-10

Referenced Screen

If the line numbers are not displayed on your system, select Tools | Options from the main menu to display the Options dialog box. If you extend the C/C++ option in the Text Editor subtree in the left pane and select General from the extended tree, you can select Line Numbers in the right pane of the dialog box. I’ll first give you a rough guide to what this code in Figure 1-10 does, and you’ll see more on all of this later.

The first two lines are just comments. Anything following “//” in a line is ignored by the compiler. When you want to add descriptive comments in a line, precede your text with “//”.

Line 4 is an #include directive that adds the contents of the file stdafx.h to this file in place of this #include directive. This is the standard way to add the contents of .h source files to a .cpp source file in a C++ program.

Line 7 is the first line of the executable code in this file and the beginning of the function _tmain(). A function is simply a named unit of executable code in a C++ program; every C++ program consists of at least one — and usually many more — functions.

Lines 8 and 10 contain left and right braces, respectively, that enclose all the executable code in the function _tmain(). The executable code is, therefore, just the single line 9, and all this does is end the program.

Now you can add the following two lines of code in the Editor window:

// Ex1_01.cpp : Defines the entry point for the console application.
//
        
#include "stdafx.h"
#include <iostream>
        
int _tmain(int argc, _TCHAR* argv[])
{
 std::cout << "Hello world!\n";
  return 0;
}

The new lines you should add are shown in bold; the others are generated for you. To introduce each new line, place the cursor at the end of the text on the preceding line and press Enter to create an empty line in which you can type the new code. Make sure it is exactly as shown in the preceding example; otherwise the program may not compile.

The first new line is an #include directive that adds the contents of one of the standard libraries for ISO/IEC C++ to the source file. The iostream library defines facilities for basic I/O operations, and the one you are using in the second line that you added writes output to the command line. std::cout is the name of the standard output stream, and you write the string “Hello world!\n” to std::cout in the second addition statement. Whatever appears between the pair of double-quote characters is written to the command line.

Building the Solution

To build the solution, press F7 or select the Build | Build Solution menu item. Alternatively, you can click the toolbar button corresponding to this menu item. The toolbar buttons for the Build menu may not be displayed, but you can easily fix this by right-clicking in the toolbar area and selecting the Build toolbar from those in the list. The program should then compile successfully. If there are errors, it may be that you created them while entering the new code, so check the two new lines very carefully.

Files Created by Building a Console Application

After the example has been built without error, take a look in the project folder by using Windows Explorer to see a new subfolder to the solution folder Ex1_01 called Debug. This is the folder Ex1_01\Debug, not the folder Ex1_01\Ex1_01\Debug. This folder contains the output of the build you just performed on the project. Notice that this folder contains three files.

Other than the .exe file, which is your program in executable form, you don’t need to know much about what’s in these files. In case you’re curious, however, the .ilk file is used by the linker when you rebuild your project. It enables the linker to incrementally link the object files produced from the modified source code into the existing .exe file. This avoids the need to relink everything each time you change your program. the .pdb file contains debugging information that is used when you execute the program in debug mode. In this mode, you can dynamically inspect information generated during program execution.

There’s a Debug subdirectory in the Ex1_01 project folder too. This contains a large number of files that were created during the build process, and you can see what kind of information they contain from the Type description in Windows Explorer.

Debug and Release Versions of Your Program

You can set a range of options for a project through the Project | Ex1_01 Properties menu item. These options determine how your source code is processed during the compile and link stages. The set of options that produces a particular executable version of your program is called a configuration. When you create a new project workspace, Visual C++ 2010 automatically creates configurations for producing two versions of your application. One version, called the Debug version, includes additional information that helps you debug the program. With the Debug version of your program, you can step through the code when things go wrong, checking on the data values in the program. The other, called the Release version, has no debug information included and has the code-optimization options for the compiler turned on to provide you with the most efficient executable module. These two configurations are sufficient for your needs throughout this book, but when you need to add other configurations for an application you can do so through the Build | Configuration Manager menu. (Note that this menu item won’t appear if you haven’t got a project loaded. This is obviously not a problem, but might be confusing if you’re just browsing through the menus to see what’s there.)

You can choose which configuration of your program to work with by selecting from the dropdown list in the toolbar. If you select Configuration Manager . . . from the dropdown list, the Configuration Manager dialog box will be displayed, as shown in Figure 1-11.

Figure 1-11

Referenced Screen

You use this dialog when your solution contains multiple projects. Here you can choose configurations for each of the projects and choose which ones you want to build.

After your application has been tested using the debug configuration and appears to be working correctly, you typically rebuild the program as a release version; this produces optimized code without the debug and trace capability, so the program runs faster and occupiesless memory.

Executing the Program

After you have successfully compiled the solution, you can execute your program by pressing Ctrl+F5. You should see the window shown in Figure 1-12.

Figure 1-12

Referenced Screen

As you can see, you get the text between the double quotes written to the command line. The “\n” that appeared at the end of the text string is a special sequence called an escape sequence that denotes a newline character. Escape sequences are used to represent characters in a text string that you cannot enter directly from the keyboard.

Try it Out: Creating an Empty Console Project

The previous project contained a certain amount of excess baggage that you don’t need when working with simple C++ language examples. The precompiled headers option chosen by default resulted in the stdafx.h file being created in the project. This is a mechanism for making the compilation process more efficient when there are a lot of files in a program, but it won’t be necessary for many of our examples. In these instances, you start with an empty project to which you can add your own source files. You can see how this works by creating a new project in a new solution for a Win32 console program with the name Ex1_02. After you have entered the project name and clicked OK, click Application Settings on the left side of the dialog box that follows. You can then select “Empty project” from the additional options, as Figure 1-13 shows.

Figure 1-13

Referenced Screen

When you click Finish, the project is created as before, but this time without any source files.

By default, the project options will be set to use Unicode libraries. This makes use of a non-standard name for the main function in the program. In order to use standard native C++ in your console programs, you need to switch off the use of Unicode libraries.

Select the Project | Properties menu item, or press Alt+F7, to display the Property Pages dialog for the project. Select the General option under Configuration Properties in the left pane and select the Character Set property in the right pane. You will then be able to set the value of this property to Not Set from the drop-down list to the right of the property name, as shown in Figure 1-14. Click OK to close the dialog. You should do this for all the native C++ console program examples in the book. If you forget to do so, they won’t build. You will be using Unicode libraries in the Windows examples, though.

Figure 1-14

Referenced Screen

Next, add a new source file to the project. Right-click the Solution Explorer pane, and then select Add | New Item . . . from the context menu. A dialog box displays: click Code in the left pane and C++ File(.cpp) in the right pane. Enter the file name as Ex1_02, as shown in Figure 1-15.

Figure 1-15

Referenced Screen

When you click Add, the new file is added to the project and is displayed in the Editor window. The file is empty, of course, so nothing will be displayed. Enter the following code in the Editor window:

// Ex1_02.cpp A simple console program
#include <iostream>                    // Basic input and output library
        
int main()
{
  std::cout << "This is a simple program that outputs some text." << std::endl;
  std::cout << "You can output more lines of text" << std::endl;
  std::cout << "just by repeating the output statement like this." << std::endl;
  return 0;                            // Return to the operating system
}

Note the automatic indenting that occurs as you type the code. C++ uses indenting to make programs more readable, and the editor automatically indents each line of code that you enter based on what was in the previous line. You can change the indenting by selecting the Tools | Options . . . menu item to display the Options dialog. Selecting Text Editor | C/C++ | Tabs in the left pane of the dialog displays the indenting options in the right pane. The editor inserts tabs by default, but you can change it to insert spaces if you want.

You can also see the syntax color highlighting in action as you type. Some elements of the program are shown in different colors, as the editor automatically assigns colors to language elements depending on what they are.

The preceding code is the complete program. You probably noticed a couple of differences compared to the code generated by the application wizard in the previous example. There’s no #include directive for the stdafx.h file. You don’t have this file as part of the project here because you are not using the precompiled headers facility. The name of the function here is main; before it was _tmain. In fact all ISO/IEC C++ programs start execution in a function called main(). Microsoft also provides for this function to be called wmain when Unicode characters are used, and the name _tmain is defined to be either main or wmain (in the tchar.h header file), depending on whether or not the program is going to use Unicode characters. In the previous example the name _tmain is defined behind the scenes to be main. I’ll use the standard name main in all the native C++ examples, which is why you need to change the Character Set property value for these projects to Not Set.

The output statements are a little different. The first statement in main() is the following:

  std::cout << "This is a simple program that outputs some text." << std::endl;

You have two occurrences of the << operator, and each one sends whatever follows to std::cout, which is the standard output stream. First, the string between double quotes is sent to the stream, and then std::endl, where std::endl is defined in the standard library as a newline character. Earlier, you used the escape sequence \n for a newline character within a string between double quotes. You could have written the preceding statement as follows:

  std::cout << "This is a simple program that outputs some text.\n";

You can now build this project in the same way as the previous example. Note that any open source files in the Editor pane are saved automatically if you have not already saved them. When you have compiled the program successfully, press Ctrl+F5 to execute it. If everything works as it should, the output will be as follows:

This is a simple program that outputs some text.
You can output more lines of text
just by repeating the output statement like this.

Dealing with Errors

Of course, if you didn’t type the program correctly, you get errors reported. To see how this works you could deliberately introduce an error into the program. If you already have errors of your own, you can use those to perform this exercise. Go back to the Editor pane and delete the semicolon at the end of the second-to-last line between the braces (line 8); then rebuild the source file. The Output pane at the bottom of the application window will include the following error message:

C2143: syntax error : missing ';' before 'return'

Every error message during compilation has an error number that you can look up in the documentation. Here the problem is obvious; however, in more obscure cases, the documentation may help you figure out what is causing the error. To get the documentation on an error, click the line in the Output pane that contains the error number and then press F1. A new window displays containing further information about the error. You can try it with this simple error, if you like.

When you have corrected the error, you can then rebuild the project. The build operation works efficiently because the project definition keeps track of the status of the files making up the project. During a normal build, Visual C++ 2010 recompiles only the files that have changed since the program was last compiled or built. This means that if your project has several source files, and you’ve edited only one of the files since the project was last built, only that file is recompiled before linking to create a new .exe file.

You’ll also use CLR console programs, so the next section shows you what a CLR console project looks like.

Try it Out: Creating a CLR Console Project

Press Ctrl+Shift+N to display the New Project dialog box; then select the project type as CLR and the template as CLR Console Application, as shown in Figure 1-16.

Figure 1-16

Referenced Screen

Enter the name as Ex1_03. When you click OK, the files for the project are created. There are no options for a CLR console project, so you always start with the same set of files in a project with this template. If you want an empty project — something you won’t need with this book — there’s a separate template for this.

If you look at the Solution Explorer pane, you’ll see that there are some extra files, compared to a Win32 console project.

There are a couple of files in the virtual Resource Files folder. The .ico file stores an icon for the application that is displayed when the program is minimized; the .rc file records the resources for the application — just the icon in this case.

There is also a file with the name AssemblyInfo.cpp. Every CLR program consists of one or more assemblies, an assembly being a collection of code and resources that forms a functional unit. An assembly also contains extensive data for the CLR; there are specifications of the data types being used, versioning information about the code, and information that determines if the contents of the assembly can be accessed from another assembly. In short, an assembly is a fundamental building block in all CLR programs.

If the source code in the Ex1_03.cpp file is not displayed in the Editor window, double-click the file name in the Solution Explorer pane. The source code has the same #include directive as the default native C++ console program because CLR programs use precompiled headers for efficiency. The next line is new:

using namespace System;

The .NET library facilities are all defined within a namespace, and all the standard sort of stuff you are likely to use is in a namespace with the name System. This statement indicates the program code that follows uses the System namespace, but what exactly is a namespace?

A namespace is a very simple concept. Within your program code and within the code that forms the .NET libraries, names have to be given to lots of things — data types, variables, and blocks of code called functions all have to have names. The problem is that if you happen to invent a name that is already used in the library, there’s potential for confusion. A namespace provides a way of getting around this problem. All the names in the library code defined within the System namespace are implicitly prefixed with the namespace name. So a name such as String in the library is really System::String. This means that if you have inadvertently used the name String for something in your code, you can use System::String to refer to String from the .NET library without confusing it with the name String in your code.

The two colons (::) are an operator called the scope resolution operator. Here the scope resolution operator separates the namespace name System from the type name String. You have seen this operator in the native C++ examples earlier in this chapter with std::cout and std::endl. This is the same story — std is the namespace name for native C++ libraries, and cout and endl are the names that have been defined within the std namespace to represent the standard output stream and the newline character, respectively.

In fact, the using namespace statement in this example enables you to use any name from the System namespace without having to use the namespace name as a prefix. If you did end up with a name conflict between a name you defined and a name in the library, you could resolve the problem by removing the using namespace statement and explicitly qualifying the name from the library with the namespace name. You learn more about namespaces in Chapter 2.

You can compile and execute the program by pressing Ctrl+F5. The output window should contain the following:

Hello World
NoteNote

At the time of writing, the console window for a C++/CLI program does not remain on the screen when you press Ctrl+F5. It is displayed briefly, and then immediately disappears. If you find this is still the case with your installation, put the following line immediately before any return statement in the main() function:

Console::ReadLine();

The program will pause with the console window displayed when this statement executes. Just press the Enter key to continue and allow the program to end. You may need to do this for all C++/CLI console program examples to see the output.

The other possibility is to open a command prompt window for the folder that contains the .exe file for the program. With Windows Vista or Windows 7, you can do this by holding down the Shift key while you right-click the folder in Windows Explorer and then selecting Open Command Window Here from the context menu. You can then execute the program from the command prompt by entering the name of the .exe file.

The output is similar to that from the first example. This output is produced by the following line:

Console::WriteLine(L"Hello World");

This uses a .NET library function to write the information between the double quotes to the command line, so this is the CLR equivalent of the native C++ statement that you added to Ex1_01:

  std::cout << "Hello world!\n";

What the CLR statement does is more immediately apparent than what the native C++ statement does.

Setting Options in Visual C++ 2010

Two sets of options are available. You can set options that apply to the tools provided by Visual C++ 2010, which apply in every project context. You also can set options that are specific to a project, and that determine how the project code is to be processed when it is compiled and linked. Options that apply to every project are set through the Options dialog box that’s displayed when you select Tools | Options from the main menu. You used this dialog earlier to change the code indenting used by the editor. The Options dialog box is shown in Figure 1-17.

Figure 1-17

Referenced Screen

Clicking the [unfilled] symbol for any of the items in the left pane displays a list of subtopics. Figure 1-17 shows the options for the General subtopic under Projects and Solutions. The right pane displays the options you can set for the topic you have selected in the left pane. You should concern yourself with only a few of these at this time, but you’ll find it useful to spend a little time browsing the range of options available to you. Clicking the Help button (the one with the question mark) at the top right of the dialog box displays an explanation of the current options.

You probably want to choose a path to use as a default when you create a new project, and you can do this through the first option shown in Figure 1-17. Just set the path to the location where you want your projects and solutions stored.

You can set options that apply to every C++ project by selecting the Projects and Solutions | VC++ Project Settings topic in the left pane. You can also set options specific to the current project through the Project | Properties menu item in the main menu, or by pressing Alt+F7. This menu item label is tailored to reflect the name of the current project. You used this to change the value of the Character Set property for the Ex1_02 console program.

Creating and Executing Windows Applications

Just to show how easy it’s going to be, you can now create two working Windows applications. You’ll create a native C++ application using MFC, and then you’ll create a Windows Forms application that runs with the CLR. I’ll defer discussion of the programs that you’ll generate until I’ve covered the necessary ground for you to understand it in detail. You will see, though, that the processes are straightforward.

Creating an MFC Application

To start with, if an existing project is active — as indicated by the project name’s appearing in the title bar of the Visual C++ 2010 main window — you can select Close Solution from the File menu. Alternatively, you can create a new project and have the current solution closed automatically.

To create the Windows program, select New | Project from the File menu or press Ctrl+Shift+N; then set the project type as MFC, and select MFC Application as the project template. You can then enter the project name as Ex1_04. When you click OK the MFC Application Wizard dialog box is displayed. The dialog box has a range of options that let you choose which features you’d like to have included in your application. These are identified by the items in the list on the left of the dialog box.

Click Application Type to display these options. Click the Tabbed documents option to deselect it and select Windows Native/Default from the drop-down list to the right. The dialog should then look as shown in Figure 1-18.

Figure 1-18

Referenced Screen

Click Advanced Features next, and uncheck Explorer docking pane, Output docking pane, Properties docking pane, ActiveX controls, and Common Control Manifest so that the dialog looks as shown in Figure 1-19.

Figure 1-19

Referenced Screen

Finally, click Finish to create the project. The undocked Solution Explorer pane in the IDE window will look as shown in Figure 1-20.

The list shows the large number of source files that have been created, and several resource files. You need plenty of space on your hard drive when writing Windows programs! The files with the extension .cpp contain executable C++ source code, and the .h files contain C++ code consisting of definitions that are used by the executable code. The .ico files contain icons. The files are grouped into subfolders you can see for ease of access. These aren’t real folders, though, and they won’t appear in the project folder on your disk.

If you now take a look at the Ex1_04 solution folder and subfolders using Windows Explorer or whatever else you may have handy for looking at the files on your hard disk, you’ll notice that you have generated a total of 29 files. Four of these are in the solution folder that includes the transient .opensdf file, a further 20 are in the project folder, and the rest are in a subfolder, res, of the project folder. The files in the res subfolder contain the resources used by the program, such as the menus and icons. You get all this as a result of just entering the name you want to assign to the project. You can see why, with so many files and file names being created automatically, a separate directory for each project becomes more than just a good idea.

Figure 1-20

Referenced Screen

One of the files in the Ex1_04 project directory is ReadMe.txt, and it provides an explanation of the purpose of each of the files that the MFC Application Wizard has generated. You can take a look at it if you want, using Notepad, WordPad, or even the Visual C++ 2010 editor. To view it in the Editor window, double-click it in the Solution Explorer pane.

Building and Executing the MFC Application

Before you can execute the program, you have to build the project — that is, compile the source code and link the program modules. You do this in exactly the same way as with the console application example. To save time, press Ctrl+F5 to get the project built and then executed in a single operation.

After the project has been built, the Output window indicates that there are no errors, and the executable starts running. The window for the program you’ve generated is shown in Figure 1-21.

Figure 1-21

Referenced Screen

As you see, the window is complete with menus and a toolbar. Although there is no specific functionality in the program — that’s what you need to add to make it your program — all the menus work. You can try them out. You can even create further windows by selecting New from the File menu.

I think you’ll agree that creating a Windows program with the MFC Application Wizard hasn’t stressed too many brain cells. You’ll need to get a few more ticking away when it comes to developing the basic program you have here into a program that does something more interesting, but it won’t be that hard. Certainly, for many people, writing a serious Windows program the old-fashioned way, without the aid of Visual C++ 2010, required at least a couple of months on a brain-enhancing fish diet before making the attempt. That’s why so many programmers used to eat sushi. That’s all gone now with Visual C++ 2010. You never know, however, what’s around the corner in programming technology. If you like sushi, it’s best to continue eating it to be on the safe side.

Creating a Windows Forms Application

This is a job for another application wizard. So, create yet another new project, but this time select the type as CLR in the left pane of the New Project dialog box, and the template as Windows Forms Application. You can then enter the project name as Ex1_05. There are no options to choose from in this case, so click OK to create the project.

The Solution Explorer pane in Figure 1-22 shows the files that have been generated for this project.

There are considerably fewer files in this project — if you look in the directories, you’ll see that there are a total of 15, including the solution files. One reason is that the initial GUI is much simpler than the native C++ application using MFC. The Windows Forms application has no menus or toolbars, and there is only one window. Of course you can add all these things quite easily, but the wizard for a Windows Forms application does not assume you want them from the start.

The Editor window looks rather different for this project, as Figure 1-23 shows.

The Editor window shows an image of the application window rather than code. The reason for this is that developing the GUI for a Windows Forms application is oriented toward a graphical design approach rather than a coding approach. You add GUI components to the application window by dragging or placing them there graphically, and Visual C++ 2010 automatically generates the code to display them. If you press Ctrl+Alt+X or select View | Toolbox you’ll see an additional window showing a list of GUI components, as in Figure 1-24.

The Toolbox window presents a list of standard components that you can add to a Windows Forms application. If you scroll down you will see there are many more groups of controls available. You can try adding some buttons to the window for Ex1_05. Click Button in the Toolbox window list and then click in the client area of the Ex1_05 application window, displayed in the Editor window, where you want the button to be placed. You can adjust the size of the button by dragging its borders, and you can reposition the button by dragging it around. You can also change the caption. Right-click the button, select Properties from the pop-up, and then select the button1 value for the Text property in the Appearance group of properties. You can then enter Start on the keyboard and then press Enter to change the button label. The Properties window shows many other properties for the button as well. I won’t go into these now, but essentially they are the specifications that affect the appearance of the button, and you can change them to suit your application.

Figure 1-22

Referenced Screen

Figure 1-23

Referenced Screen

Figure 1-24

Referenced Screen

Try adding another button with the label Stop, for example. The Editor window will look as shown in Figure 1-25.

You can graphically edit any of the GUI components at any time, and the code adjusts automatically. Try adding a few other components in the same way and then compile and execute the example by pressing Ctrl+F5. The application window displays in all its glory. Couldn’t be easier, could it?

In this chapter you have run through the basic mechanics of using Visual C++ 2010 to create applications of various kinds. You created and executed native and CLR console programs, and with the help of the application wizards you created an MFC-based Windows program and a Windows Forms program that executes with the CLR.

Starting with the next chapter, you’ll use console applications extensively throughout the first half of the book. All the examples illustrating how C++ language elements are used are executed using either Win32 or CLR console applications. You will return to the application wizard for MFC-based programs and Windows Forms applications as soon as you have finished delving into the secrets of C++.

Figure 1-25

Referenced Screen

Topic

Concept

The Common Language Runtime

The Common Language Runtime (CLR) is the Microsoft implementation of the Common Language Infrastructure (CLI) standard.

The .NET Framework

The .NET Framework comprises the CLR plus the .NET libraries that support applications targeting the CLR.

Native C++

Native C++ applications are written in the ISO/IEC C++ language.

C++/CLI

Programs written in the C++/CLI language execute with the CLR.

Attributes

Attributes can provide additional information to the compiler to instruct it to modify or extend particular programming elements in a program.

Solutions

A solution is a container for one or more projects that form a solution to an information-processing problem of some kind.

Projects

A project is a container for the code and resource elements that make up a functional unit in a program.

Assemblies

An assembly is a fundamental unit in a CLR program. All CLR programs are made up of one or more assemblies.

Ivor Horton’s Beginning Visual C++® 2010, Copyright © 2010 by Ivor Horton, ISBN: 978-0-470-50088-0, Published by Wiley Publishing, Inc., All Rights Reserved. Wrox, the Wrox logo, Wrox Programmer to Programmer, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc and/or its affiliates.

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