CodeDomProvider Class

Provides a base class for CodeDomProvider implementations. This class is abstract.

Namespace: System.CodeDom.Compiler
Assembly: System (in system.dll)

'Declaration
<ComVisibleAttribute(True)> _
Public MustInherit Class CodeDomProvider
	Inherits Component
'Usage
Dim instance As CodeDomProvider

/** @attribute ComVisibleAttribute(true) */ 
public abstract class CodeDomProvider extends Component
ComVisibleAttribute(true) 
public abstract class CodeDomProvider extends Component
Not applicable.

A CodeDomProvider can be used to create and retrieve instances of code generators and code compilers. Code generators can be used to generate code in a particular language, and code compilers can be used to compile code into assemblies.

NoteNote:

In the Microsoft .NET Framework version 2.0, the methods made available in the code generator and code compiler are available directly from the code provider. You do not need to call CreateGenerator or CreateCompiler to access the methods, and those methods are marked as obsolete. This applies to preexisting as well as new code provider implementations.

A CodeDomProvider implementation typically provides code generation and/or code compilation interfaces for generating code and managing compilation for a single programming language. Several languages are supported by CodeDomProvider implementations that ship with the .NET Framework SDK. These languages include C#, Visual Basic, C++, J#, and JScript. Developers or compiler vendors can implement the ICodeGenerator and ICodeCompiler interfaces and provide a CodeDomProvider that extends CodeDom support to other programming languages.

The <system.codedom> Element in the machine configuration file (Machine.config) provides a mechanism for developers and compiler vendors to add configuration settings for additional CodeDomProvider implementations.

The CodeDomProvider class provides static methods to discover and enumerate the CodeDomProvider implementations on a computer. The GetAllCompilerInfo method returns the settings for all CodeDomProvider implementations on a computer. The GetCompilerInfo method returns the settings for a specific CodeDomProvider implementation, based on the programming language name. The CreateProvider method returns an instance of a CodeDomProvider implementation for a specific language.

For more details on language provider settings in the configuration file, see Compiler and Language Provider Settings Schema.

NoteNote:

This class makes a link demand and an inheritance demand at the class level. A SecurityException is thrown if either the immediate caller or the derived class does not have full trust permission. For details about security demands, see Link Demands and Inheritance Demands.

Notes to Inheritors: In the .NET Framework versions 1.0 and 1.1, code providers consist of implementations of CodeDomProvider, ICodeGenerator, ICodeParser, and ICodeCompiler. In the .NET Framework 2.0, the CreateGenerator, CreateParser, and CreateCompiler methods are obsolete, and the methods of ICodeGenerator and ICodeCompiler are directly available in the CodeDomProvider class. You should override those methods in your code provider implementation and not call the base methods.

The following example program can generate and compile source code based on a CodeDOM model of a program that prints "Hello World" using the Console class. A Windows Forms user interface is provided. The user can select the target programming language from several selections: C#, Visual Basic, and JScript.

Imports System
Imports System.CodeDom
Imports System.CodeDom.Compiler
Imports System.Collections
Imports System.ComponentModel
Imports System.Diagnostics
Imports System.Drawing
Imports System.IO
Imports System.Windows.Forms
Imports Microsoft.CSharp
Imports Microsoft.VisualBasic
Imports Microsoft.JScript

' This example demonstrates building a Hello World program graph 
' using System.CodeDom elements. It calls code generator and
' code compiler methods to build the program using CSharp, VB, or
' JScript.  A Windows Forms interface is included. Note: Code
' must be compiled and linked with the Microsoft.JScript assembly. 
Namespace CodeDOMExample

    Class CodeDomExample
        ' Build a Hello World program graph using 
        ' System.CodeDom types.
        Public Shared Function BuildHelloWorldGraph() As CodeCompileUnit

            ' Create a new CodeCompileUnit to contain 
            ' the program graph.
            Dim compileUnit As New CodeCompileUnit()

            ' Declare a new namespace called Samples.
            Dim samples As New CodeNamespace("Samples")

            ' Add the new namespace to the compile unit.
            compileUnit.Namespaces.Add(samples)

            ' Add the new namespace import for the System namespace.
            samples.Imports.Add(New CodeNamespaceImport("System"))

            ' Declare a new type called Class1.
            Dim class1 As New CodeTypeDeclaration("Class1")

            ' Add the new type to the namespace type collection.
            samples.Types.Add(class1)

            ' Declare a new code entry point method.
            Dim start As New CodeEntryPointMethod()

            ' Create a type reference for the System.Console class.
            Dim csSystemConsoleType As New CodeTypeReferenceExpression( _
                "System.Console")

            ' Build a Console.WriteLine statement.
            Dim cs1 As New CodeMethodInvokeExpression( _
                csSystemConsoleType, "WriteLine", _
                New CodePrimitiveExpression("Hello World!"))

            ' Add the WriteLine call to the statement collection.
            start.Statements.Add(cs1)

            ' Build another Console.WriteLine statement.
            Dim cs2 As New CodeMethodInvokeExpression( _
                csSystemConsoleType, "WriteLine", _
                New CodePrimitiveExpression("Press the Enter key to continue."))

            ' Add the WriteLine call to the statement collection.
            start.Statements.Add(cs2)

            ' Build a call to System.Console.ReadLine.
            Dim csReadLine As New CodeMethodInvokeExpression( _
                csSystemConsoleType, "ReadLine")

            ' Add the ReadLine statement.
            start.Statements.Add(csReadLine)

            ' Add the code entry point method to
            ' the Members collection of the type.
            class1.Members.Add(start)

            Return compileUnit
        End Function

        Public Shared Sub GenerateCode(ByVal provider As CodeDomProvider, ByVal compileunit As CodeCompileUnit)

            ' Build the source file name with the appropriate
            ' language extension.
            Dim sourceFile As String
            If provider.FileExtension.StartsWith(".") Then
                sourceFile = "TestGraph" + provider.FileExtension
            Else
                sourceFile = "TestGraph." + provider.FileExtension
            End If

            ' Create an IndentedTextWriter, constructed with
            ' a StreamWriter to the source file.
            Dim tw As New IndentedTextWriter(New StreamWriter(sourceFile, False), "    ")
            ' Generate source code using the code generator.
            provider.GenerateCodeFromCompileUnit(compileunit, tw, New CodeGeneratorOptions())
            ' Close the output file.
            tw.Close()
        End Sub

        Public Shared Function CompileCode(ByVal provider As CodeDomProvider, _
                                           ByVal sourceFile As String, _
                                           ByVal exeFile As String) As CompilerResults

            ' Configure a CompilerParameters that links System.dll
            ' and produces the specified executable file.
            Dim referenceAssemblies As String() = {"System.dll"}
            Dim cp As New CompilerParameters(referenceAssemblies, exeFile, False)

            ' Generate an executable rather than a DLL file.
            cp.GenerateExecutable = True

            ' Invoke compilation.
            Dim cr As CompilerResults = provider.CompileAssemblyFromFile(cp, _
                sourceFile)
            ' Return the results of compilation.
            Return cr
        End Function
    End Class

    Public Class CodeDomExampleForm
        Inherits System.Windows.Forms.Form
        Private run_button As New System.Windows.Forms.Button()
        Private compile_button As New System.Windows.Forms.Button()
        Private generate_button As New System.Windows.Forms.Button()
        Private textBox1 As New System.Windows.Forms.TextBox()
        Private comboBox1 As New System.Windows.Forms.ComboBox()
        Private label1 As New System.Windows.Forms.Label()

        Private Sub generate_button_Click(ByVal sender As Object, ByVal e As System.EventArgs)
            Dim provider As CodeDomProvider = GetCurrentProvider()
            CodeDomExample.GenerateCode(provider, CodeDomExample.BuildHelloWorldGraph())

            ' Build the source file name with the appropriate
            ' language extension.
            Dim sourceFile As String
            If provider.FileExtension.StartsWith(".") Then
                sourceFile = "TestGraph" + provider.FileExtension
            Else
                sourceFile = "TestGraph." + provider.FileExtension
            End If

            ' Read in the generated source file and
            ' display the source text.
            Dim sr As New StreamReader(sourceFile)
            textBox1.Text = sr.ReadToEnd()
            sr.Close()
        End Sub

        Private Sub compile_button_Click(ByVal sender As Object, ByVal e As System.EventArgs)
            Dim provider As CodeDomProvider = GetCurrentProvider()

            ' Build the source file name with the appropriate
            ' language extension.
            Dim sourceFile As String
            If provider.FileExtension.StartsWith(".") Then
                sourceFile = "TestGraph" + provider.FileExtension
            Else
                sourceFile = "TestGraph." + provider.FileExtension
            End If

            Dim cr As CompilerResults = CodeDomExample.CompileCode(provider, _
                                                                   sourceFile, _
                                                                   "TestGraph.EXE")

            If cr.Errors.Count > 0 Then
                ' Display compilation errors.
                textBox1.Text = "Errors encountered while building " + _
                                sourceFile + " into " + _
                                cr.PathToAssembly + ": " + ControlChars.CrLf

                Dim ce As System.CodeDom.Compiler.CompilerError
                For Each ce In cr.Errors
                    textBox1.AppendText(ce.ToString() + ControlChars.CrLf)
                Next ce
                run_button.Enabled = False
            Else
                textBox1.Text = "Source " + sourceFile + " built into " + _
                                cr.PathToAssembly + " with no errors."
                run_button.Enabled = True
            End If
        End Sub

        Private Sub run_button_Click(ByVal sender As Object, _
            ByVal e As System.EventArgs)

            Process.Start("TestGraph.EXE")
        End Sub

        Private Function GetCurrentProvider() As CodeDomProvider

            Dim provider As CodeDomProvider
            Select Case CStr(Me.comboBox1.SelectedItem)
                Case "CSharp"
                    provider = CodeDomProvider.CreateProvider("CSharp")
                Case "Visual Basic"
                    provider = CodeDomProvider.CreateProvider("VisualBasic")
                Case "JScript"
                    provider = CodeDomProvider.CreateProvider("JScript")
                Case Else
                    provider = CodeDomProvider.CreateProvider("CSharp")
            End Select
            Return provider
        End Function

        Public Sub New()
            Me.SuspendLayout()
            ' Set properties for label1.
            Me.label1.Location = New System.Drawing.Point(395, 20)
            Me.label1.Size = New Size(180, 22)
            Me.label1.Text = "Select a programming language:"
            ' Set properties for comboBox1.
            Me.comboBox1.Location = New System.Drawing.Point(560, 16)
            Me.comboBox1.Size = New Size(190, 23)
            Me.comboBox1.Name = "comboBox1"
            Me.comboBox1.Items.AddRange(New String() {"CSharp", "Visual Basic", "JScript"})
            Me.comboBox1.Anchor = System.Windows.Forms.AnchorStyles.Left Or System.Windows.Forms.AnchorStyles.Right Or System.Windows.Forms.AnchorStyles.Top
            Me.comboBox1.SelectedIndex = 0
            ' Set properties for generate_button.
            Me.generate_button.Location = New System.Drawing.Point(8, 16)
            Me.generate_button.Name = "generate_button"
            Me.generate_button.Size = New System.Drawing.Size(120, 23)
            Me.generate_button.Text = "Generate Code"
            AddHandler generate_button.Click, AddressOf Me.generate_button_Click
            ' Set properties for compile_button.
            Me.compile_button.Location = New System.Drawing.Point(136, 16)
            Me.compile_button.Name = "compile_button"
            Me.compile_button.Size = New System.Drawing.Size(120, 23)
            Me.compile_button.Text = "Compile"
            AddHandler compile_button.Click, AddressOf Me.compile_button_Click
            ' Set properties for run_button.
            Me.run_button.Enabled = False
            Me.run_button.Location = New System.Drawing.Point(264, 16)
            Me.run_button.Name = "run_button"
            Me.run_button.Size = New System.Drawing.Size(120, 23)
            Me.run_button.Text = "Run"
            AddHandler run_button.Click, AddressOf Me.run_button_Click
            ' Set properties for textBox1.
            Me.textBox1.Anchor = System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left Or System.Windows.Forms.AnchorStyles.Right
            Me.textBox1.Location = New System.Drawing.Point(8, 48)
            Me.textBox1.Multiline = True
            Me.textBox1.ScrollBars = System.Windows.Forms.ScrollBars.Vertical
            Me.textBox1.Name = "textBox1"
            Me.textBox1.Size = New System.Drawing.Size(744, 280)
            Me.textBox1.Text = ""
            ' Set properties for the CodeDomExampleForm.
            Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
            Me.ClientSize = New System.Drawing.Size(768, 340)
            Me.MinimumSize = New System.Drawing.Size(750, 340)
            Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.textBox1, _
                Me.run_button, Me.compile_button, Me.generate_button, _
                Me.comboBox1, Me.label1})
            Me.Name = "CodeDomExampleForm"
            Me.Text = "CodeDom Hello World Example"
            Me.ResumeLayout(False)
        End Sub

        Protected Overloads Sub Dispose(ByVal disposing As Boolean)
            MyBase.Dispose(disposing)
        End Sub

        <STAThread()> _
        Shared Sub Main()
            Application.Run(New CodeDomExampleForm())
        End Sub
    End Class
End Namespace

  • SecurityAction.LinkDemand  for full trust for the immediate caller. This class cannot be used by partially trusted code.
  • SecurityAction.InheritanceDemand  for full trust for inheritors. This class cannot be inherited by partially trusted code.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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