Designing User Interfaces
The .NET Micro Framework and Windows Presentation Foundation
To enable you to create user interfaces in an efficient and straightforward way, the .NET Micro Framework provides its own version of Windows® Presentation Foundation (WPF). As with all aspects of the .NET Micro Framework, this version of WPF is optimized for small hardware devices. Therefore, it does not support all of the functionality provided by Windows Vista™ WPF. Instead, it offers highly targeted functionality that contains only what you need to create attractive, streamlined applications for very small devices.
The .NET Micro Framework provides its WPF API elements in the namespaces listed and described in the following table.
|Microsoft.SPOT.Input||Contains tools for collecting and managing user input.|
|Microsoft.SPOT.Presentation||Provides the ability to design and control the layout and display of graphical user interface elements.|
|Microsoft.SPOT.Presentation.Controls||Enables your program to create elements (known as controls) that make it possible for users to interact with the programs. This namespace also provides support for displaying text.|
|Microsoft.SPOT.Presentation.Media||Gives your applications the tools required to draw and manipulate bitmapped images.|
|Microsoft.SPOT.Presentation.Shapes||Provides tools that enable your programs to draw two-dimensional (2-D) geometric shapes.|
User Interface Essentials
WPF helps you build applications that consist of an Application object and a set of pages. The Application object enables you to handle top-level events, and to share code and state among pages.
After creating an Application object, your program can associate one or more Window objects with the Application object. Window objects represent and display both windows and dialog boxes. Within a window or dialog box, your program can display controls, print text, show bitmaps, or draw 2-D shapes.
|The .NET Micro Framework does not support icons in resource files.|
Timers and User Interfaces
When creating your user interfaces with the .NET Micro Framework version of WPF, it is strongly recommended that you use the DispatchTimer class rather than the Timer class. This is because the WPF classes for the .NET Micro Framework are not thread-safe. You can avoid this potential problem by using objects from the DispatchTimer class.
In the .NET Micro Framework, all fonts use the
.tinyfnt file format. The TFConvert tool can create a
.tinyfnt file from a
OpenType font file. To use a font, add its
.tinyfnt file to your project's resources. Once a font resource has been added to your project, you may reference it from your application.
For example, the following code creates a text control and sets its font to the font contained in the
// Create a single text control. Text text = new Text(); // Set Font text.Font = Resources.GetFont(Resources.FontResources.small);
The .NET Micro Framework's implementation of the Windows Presentation Foundation supports both
JPEG images with the following restrictions.
- Interlaced GIF images are not supported. If the bitmap is an animated GIF that contains multiple images, the framework displays only the first image.
- Images can contain a maximum of 3 channels.
Files sizes are limited by the number of heap blocks in a heap cluster. This size limitation is different for each hardware platform. Please see your hardware's documentation for details.