如何：使用 CodeDOM 创建类

项目
04/07/2023

以下过程说明如何创建和编译 CodeDOM 图，此图会生成包含以下各项的类：两个字段、三个属性、一个方法、一个构造函数和一个入口点。

创建将使用 CodeDOM 代码生成类的源代码的控制台应用程序。

在此示例中，生成类命名为 Sample，生成的代码是名为 SampleCode 的文件中的一个名为 CodeDOMCreatedClass 的类。
在生成类中，初始化 CodeDOM 图，并使用 CodeDOM 方法定义生成类的成员、构造函数和入口点（Main 方法）。

在此示例中，生成类包含两个字段、三个属性、一个构造函数、一个方法和一个 Main 方法。
在生成类中，创建一个语言特定代码提供程序，并调用其 GenerateCodeFromCompileUnit 方法从该图生成代码。
编译并执行应用程序以生成代码。

在此示例中，生成的代码位于名为 SampleCode 的文件中。编译并执行此代码以查看样本输出。

创建将执行 CodeDOM 代码的应用程序

创建要包含 CodeDOM 代码的控制台应用程序类。定义要在该类中使用的全局字段，以便引用程序集 (CodeCompileUnit) 和类 (CodeTypeDeclaration)，指定生成的源文件的名称并声明 Main 方法。

using System;
using System.Reflection;
using System.IO;
using System.CodeDom;
using System.CodeDom.Compiler;
using Microsoft.CSharp;

namespace SampleCodeDom
{
    class Sample
    {
        CodeCompileUnit targetUnit;
        CodeTypeDeclaration targetClass;
        private const string outputFileName = "SampleCode.cs";
        static void Main(string[] args)
        {
        }
    }
}

Imports System.Reflection
Imports System.IO
Imports System.CodeDom
Imports System.CodeDom.Compiler
Imports Microsoft.CSharp



Class Sample
    Private targetUnit As CodeCompileUnit
    Private targetClass As CodeTypeDeclaration
    Private Const outputFileName As String = "SampleCode.vb"

    Shared Sub Main(ByVal args() As String)

    End Sub
End Class

初始化 CodeDOM 图

在控制台应用程序类的构造函数中，初始化程序集和类，并向 CodeDOM 图添加适当的声明。

public Sample()
{
    targetUnit = new CodeCompileUnit();
    CodeNamespace samples = new CodeNamespace("CodeDOMSample");
    samples.Imports.Add(new CodeNamespaceImport("System"));
    targetClass = new CodeTypeDeclaration("CodeDOMCreatedClass");
    targetClass.IsClass = true;
    targetClass.TypeAttributes =
        TypeAttributes.Public | TypeAttributes.Sealed;
    samples.Types.Add(targetClass);
    targetUnit.Namespaces.Add(samples);
}

Public Sub New()
    targetUnit = New CodeCompileUnit()
    Dim samples As New CodeNamespace("CodeDOMSample")
    samples.Imports.Add(New CodeNamespaceImport("System"))
    targetClass = New CodeTypeDeclaration("CodeDOMCreatedClass")
    targetClass.IsClass = True
    targetClass.TypeAttributes = _
        TypeAttributes.Public Or TypeAttributes.Sealed
    samples.Types.Add(targetClass)
    targetUnit.Namespaces.Add(samples)

End Sub

向 CodeDOM 图添加成员

通过向类的 Members 属性添加 CodeMemberField 对象，向 CodeDOM 图添加字段。

public void AddFields()
{
    // Declare the widthValue field.
    CodeMemberField widthValueField = new CodeMemberField();
    widthValueField.Attributes = MemberAttributes.Private;
    widthValueField.Name = "widthValue";
    widthValueField.Type = new CodeTypeReference(typeof(System.Double));
    widthValueField.Comments.Add(new CodeCommentStatement(
        "The width of the object."));
    targetClass.Members.Add(widthValueField);

    // Declare the heightValue field
    CodeMemberField heightValueField = new CodeMemberField();
    heightValueField.Attributes = MemberAttributes.Private;
    heightValueField.Name = "heightValue";
    heightValueField.Type =
        new CodeTypeReference(typeof(System.Double));
    heightValueField.Comments.Add(new CodeCommentStatement(
        "The height of the object."));
    targetClass.Members.Add(heightValueField);
}

Public Sub AddFields()
    ' Declare the widthValue field.
    Dim widthValueField As New CodeMemberField()
    widthValueField.Attributes = MemberAttributes.Private
    widthValueField.Name = "widthValue"
    widthValueField.Type = _
        New CodeTypeReference(GetType(System.Double))
    widthValueField.Comments.Add(New CodeCommentStatement( _
        "The width of the object."))
    targetClass.Members.Add(widthValueField)

    ' Declare the heightValue field
    Dim heightValueField As New CodeMemberField()
    heightValueField.Attributes = MemberAttributes.Private
    heightValueField.Name = "heightValue"
    heightValueField.Type = _
        New CodeTypeReference(GetType(System.Double))
    heightValueField.Comments.Add(New CodeCommentStatement( _
        "The height of the object."))
    targetClass.Members.Add(heightValueField)

End Sub

通过向类的 Members 属性添加 CodeMemberProperty 对象，向 CodeDOM 图添加属性。

public void AddProperties()
{
    // Declare the read-only Width property.
    CodeMemberProperty widthProperty = new CodeMemberProperty();
    widthProperty.Attributes =
        MemberAttributes.Public | MemberAttributes.Final;
    widthProperty.Name = "Width";
    widthProperty.HasGet = true;
    widthProperty.Type = new CodeTypeReference(typeof(System.Double));
    widthProperty.Comments.Add(new CodeCommentStatement(
        "The Width property for the object."));
    widthProperty.GetStatements.Add(new CodeMethodReturnStatement(
        new CodeFieldReferenceExpression(
        new CodeThisReferenceExpression(), "widthValue")));
    targetClass.Members.Add(widthProperty);

    // Declare the read-only Height property.
    CodeMemberProperty heightProperty = new CodeMemberProperty();
    heightProperty.Attributes =
        MemberAttributes.Public | MemberAttributes.Final;
    heightProperty.Name = "Height";
    heightProperty.HasGet = true;
    heightProperty.Type = new CodeTypeReference(typeof(System.Double));
    heightProperty.Comments.Add(new CodeCommentStatement(
        "The Height property for the object."));
    heightProperty.GetStatements.Add(new CodeMethodReturnStatement(
        new CodeFieldReferenceExpression(
        new CodeThisReferenceExpression(), "heightValue")));
    targetClass.Members.Add(heightProperty);

    // Declare the read only Area property.
    CodeMemberProperty areaProperty = new CodeMemberProperty();
    areaProperty.Attributes =
        MemberAttributes.Public | MemberAttributes.Final;
    areaProperty.Name = "Area";
    areaProperty.HasGet = true;
    areaProperty.Type = new CodeTypeReference(typeof(System.Double));
    areaProperty.Comments.Add(new CodeCommentStatement(
        "The Area property for the object."));

    // Create an expression to calculate the area for the get accessor
    // of the Area property.
    CodeBinaryOperatorExpression areaExpression =
        new CodeBinaryOperatorExpression(
        new CodeFieldReferenceExpression(
        new CodeThisReferenceExpression(), "widthValue"),
        CodeBinaryOperatorType.Multiply,
        new CodeFieldReferenceExpression(
        new CodeThisReferenceExpression(), "heightValue"));
    areaProperty.GetStatements.Add(
        new CodeMethodReturnStatement(areaExpression));
    targetClass.Members.Add(areaProperty);
}

Public Sub AddProperties()
    ' Declare the read only Width property.
    Dim widthProperty As New CodeMemberProperty()
    widthProperty.Attributes = _
        MemberAttributes.Public Or MemberAttributes.Final
    widthProperty.Name = "Width"
    widthProperty.HasGet = True
    widthProperty.Type = New CodeTypeReference(GetType(System.Double))
    widthProperty.Comments.Add(New CodeCommentStatement( _
        "The width property for the object."))
    widthProperty.GetStatements.Add(New CodeMethodReturnStatement( _
        New CodeFieldReferenceExpression( _
        New CodeThisReferenceExpression(), "widthValue")))
    targetClass.Members.Add(widthProperty)

    ' Declare the read-only Height property.
    Dim heightProperty As New CodeMemberProperty()
    heightProperty.Attributes = _
        MemberAttributes.Public Or MemberAttributes.Final
    heightProperty.Name = "Height"
    heightProperty.HasGet = True
    heightProperty.Type = New CodeTypeReference(GetType(System.Double))
    heightProperty.Comments.Add(New CodeCommentStatement( _
        "The Height property for the object."))
    heightProperty.GetStatements.Add(New CodeMethodReturnStatement( _
        New CodeFieldReferenceExpression( _
        New CodeThisReferenceExpression(), "heightValue")))
    targetClass.Members.Add(heightProperty)

    ' Declare the read only Area property.
    Dim areaProperty As New CodeMemberProperty()
    areaProperty.Attributes = _
        MemberAttributes.Public Or MemberAttributes.Final
    areaProperty.Name = "Area"
    areaProperty.HasGet = True
    areaProperty.Type = New CodeTypeReference(GetType(System.Double))
    areaProperty.Comments.Add(New CodeCommentStatement( _
        "The Area property for the object."))

    ' Create an expression to calculate the area for the get accessor
    ' of the Area property.
    Dim areaExpression As New CodeBinaryOperatorExpression( _
        New CodeFieldReferenceExpression( _
        New CodeThisReferenceExpression(), "widthValue"), _
        CodeBinaryOperatorType.Multiply, _
        New CodeFieldReferenceExpression( _
        New CodeThisReferenceExpression(), "heightValue"))
    areaProperty.GetStatements.Add( _
        New CodeMethodReturnStatement(areaExpression))
    targetClass.Members.Add(areaProperty)

End Sub

通过向类的 Members 属性添加 CodeMemberMethod 对象，向 CodeDOM 图添加方法。

public void AddMethod()
{
    // Declaring a ToString method
    CodeMemberMethod toStringMethod = new CodeMemberMethod();
    toStringMethod.Attributes =
        MemberAttributes.Public | MemberAttributes.Override;
    toStringMethod.Name = "ToString";
    toStringMethod.ReturnType =
        new CodeTypeReference(typeof(System.String));

    CodeFieldReferenceExpression widthReference =
        new CodeFieldReferenceExpression(
        new CodeThisReferenceExpression(), "Width");
    CodeFieldReferenceExpression heightReference =
        new CodeFieldReferenceExpression(
        new CodeThisReferenceExpression(), "Height");
    CodeFieldReferenceExpression areaReference =
        new CodeFieldReferenceExpression(
        new CodeThisReferenceExpression(), "Area");

    // Declaring a return statement for method ToString.
    CodeMethodReturnStatement returnStatement =
        new CodeMethodReturnStatement();

    // This statement returns a string representation of the width,
    // height, and area.
    string formattedOutput = "The object:" + Environment.NewLine +
        " width = {0}," + Environment.NewLine +
        " height = {1}," + Environment.NewLine +
        " area = {2}";
    returnStatement.Expression =
        new CodeMethodInvokeExpression(
        new CodeTypeReferenceExpression("System.String"), "Format",
        new CodePrimitiveExpression(formattedOutput),
        widthReference, heightReference, areaReference);
    toStringMethod.Statements.Add(returnStatement);
    targetClass.Members.Add(toStringMethod);
}

Public Sub AddMethod()
    ' Declaring a ToString method.
    Dim toStringMethod As New CodeMemberMethod()
    toStringMethod.Attributes = _
        MemberAttributes.Public Or MemberAttributes.Override
    toStringMethod.Name = "ToString"
    toStringMethod.ReturnType = _
        New CodeTypeReference(GetType(System.String))

    Dim widthReference As New CodeFieldReferenceExpression( _
        New CodeThisReferenceExpression(), "Width")
    Dim heightReference As New CodeFieldReferenceExpression( _
        New CodeThisReferenceExpression(), "Height")
    Dim areaReference As New CodeFieldReferenceExpression( _
        New CodeThisReferenceExpression(), "Area")

    ' Declaring a return statement for method ToString.
    Dim returnStatement As New CodeMethodReturnStatement()

    ' This statement returns a string representation of the width,
    ' height, and area.
    Dim formattedOutput As String = "The object:" & Environment.NewLine _
        & " width = {0}," & Environment.NewLine & " height = {1}," _
        & Environment.NewLine & " area = {2}"
    returnStatement.Expression = New CodeMethodInvokeExpression( _
        New CodeTypeReferenceExpression("System.String"), "Format", _
        New CodePrimitiveExpression(formattedOutput), widthReference, _
        heightReference, areaReference)
    toStringMethod.Statements.Add(returnStatement)
    targetClass.Members.Add(toStringMethod)

End Sub

通过向类的 Members 属性添加 CodeConstructor 对象，向 CodeDOM 图添加构造函数。

public void AddConstructor()
{
    // Declare the constructor
    CodeConstructor constructor = new CodeConstructor();
    constructor.Attributes =
        MemberAttributes.Public | MemberAttributes.Final;

    // Add parameters.
    constructor.Parameters.Add(new CodeParameterDeclarationExpression(
        typeof(System.Double), "width"));
    constructor.Parameters.Add(new CodeParameterDeclarationExpression(
        typeof(System.Double), "height"));

    // Add field initialization logic
    CodeFieldReferenceExpression widthReference =
        new CodeFieldReferenceExpression(
        new CodeThisReferenceExpression(), "widthValue");
    constructor.Statements.Add(new CodeAssignStatement(widthReference,
        new CodeArgumentReferenceExpression("width")));
    CodeFieldReferenceExpression heightReference =
        new CodeFieldReferenceExpression(
        new CodeThisReferenceExpression(), "heightValue");
    constructor.Statements.Add(new CodeAssignStatement(heightReference,
        new CodeArgumentReferenceExpression("height")));
    targetClass.Members.Add(constructor);
}

Public Sub AddConstructor()
    ' Declare the constructor
    Dim constructor As New CodeConstructor()
    constructor.Attributes = _
        MemberAttributes.Public Or MemberAttributes.Final

    ' Add parameters.
    constructor.Parameters.Add( _
        New CodeParameterDeclarationExpression( _
        GetType(System.Double), "width"))
    constructor.Parameters.Add( _
        New CodeParameterDeclarationExpression( _
        GetType(System.Double), "height"))

    ' Add field initialization logic
    Dim widthReference As New CodeFieldReferenceExpression( _
        New CodeThisReferenceExpression(), "widthValue")
    constructor.Statements.Add(New CodeAssignStatement( _
        widthReference, New CodeArgumentReferenceExpression("width")))
    Dim heightReference As New CodeFieldReferenceExpression( _
        New CodeThisReferenceExpression(), "heightValue")
    constructor.Statements.Add( _
        New CodeAssignStatement(heightReference, _
        New CodeArgumentReferenceExpression("height")))
    targetClass.Members.Add(constructor)

End Sub

通过向类的 Members 属性添加 CodeEntryPointMethod 对象，向 CodeDOM 图添加入口点。

public void AddEntryPoint()
{
    CodeEntryPointMethod start = new CodeEntryPointMethod();
    CodeObjectCreateExpression objectCreate =
        new CodeObjectCreateExpression(
        new CodeTypeReference("CodeDOMCreatedClass"),
        new CodePrimitiveExpression(5.3),
        new CodePrimitiveExpression(6.9));

    // Add the statement:
    // "CodeDOMCreatedClass testClass =
    //     new CodeDOMCreatedClass(5.3, 6.9);"
    start.Statements.Add(new CodeVariableDeclarationStatement(
        new CodeTypeReference("CodeDOMCreatedClass"), "testClass",
        objectCreate));

    // Creat the expression:
    // "testClass.ToString()"
    CodeMethodInvokeExpression toStringInvoke =
        new CodeMethodInvokeExpression(
        new CodeVariableReferenceExpression("testClass"), "ToString");

    // Add a System.Console.WriteLine statement with the previous
    // expression as a parameter.
    start.Statements.Add(new CodeMethodInvokeExpression(
        new CodeTypeReferenceExpression("System.Console"),
        "WriteLine", toStringInvoke));
    targetClass.Members.Add(start);
}

Public Sub AddEntryPoint()
    Dim start As New CodeEntryPointMethod()
    Dim objectCreate As New CodeObjectCreateExpression( _
        New CodeTypeReference("CodeDOMCreatedClass"), _
        New CodePrimitiveExpression(5.3), _
        New CodePrimitiveExpression(6.9))

    ' Add the statement:
    ' "CodeDOMCreatedClass testClass = _
    '     new CodeDOMCreatedClass(5.3, 6.9);"
    start.Statements.Add(New CodeVariableDeclarationStatement( _
        New CodeTypeReference("CodeDOMCreatedClass"), _
        "testClass", objectCreate))

    ' Creat the expression:
    ' "testClass.ToString()"
    Dim toStringInvoke As New CodeMethodInvokeExpression( _
        New CodeVariableReferenceExpression("testClass"), "ToString")

    ' Add a System.Console.WriteLine statement with the previous 
    ' expression as a parameter.
    start.Statements.Add(New CodeMethodInvokeExpression( _
        New CodeTypeReferenceExpression("System.Console"), _
        "WriteLine", toStringInvoke))
    targetClass.Members.Add(start)

End Sub

从 CodeDOM 图生成代码

通过调用 GenerateCodeFromCompileUnit 方法，从 CodeDOM 图生成源代码。

public void GenerateCSharpCode(string fileName)
{
    CodeDomProvider provider = CodeDomProvider.CreateProvider("CSharp");
    CodeGeneratorOptions options = new CodeGeneratorOptions();
    options.BracingStyle = "C";
    using (StreamWriter sourceWriter = new StreamWriter(fileName))
    {
        provider.GenerateCodeFromCompileUnit(
            targetUnit, sourceWriter, options);
    }
}

Public Sub GenerateVBCode(ByVal fileName As String)
    Dim provider As CodeDomProvider
    provider = CodeDomProvider.CreateProvider("VisualBasic")
    Dim options As New CodeGeneratorOptions()
    Dim sourceWriter As New StreamWriter(fileName)
    Try
        provider.GenerateCodeFromCompileUnit( _
            targetUnit, sourceWriter, options)
    Finally
        sourceWriter.Dispose()
    End Try

End Sub

创建图并生成代码

将以上步骤中创建的方法添加到第一步中定义的 Main 方法中。

static void Main()
{
    Sample sample = new Sample();
    sample.AddFields();
    sample.AddProperties();
    sample.AddMethod();
    sample.AddConstructor();
    sample.AddEntryPoint();
    sample.GenerateCSharpCode(outputFileName);
}

    Shared Sub Main()
        Dim sample As New Sample()
        sample.AddFields()
        sample.AddProperties()
        sample.AddMethod()
        sample.AddConstructor()
        sample.AddEntryPoint()
        sample.GenerateVBCode(outputFileName)

    End Sub
End Class

编译并执行生成类。

示例

以下代码示例显示了上述步骤中的代码。

using System;
using System.Reflection;
using System.IO;
using System.CodeDom;
using System.CodeDom.Compiler;
using Microsoft.CSharp;

namespace SampleCodeDom
{
    /// <summary>
    /// This code example creates a graph using a CodeCompileUnit and
    /// generates source code for the graph using the CSharpCodeProvider.
    /// </summary>
    class Sample
    {
        /// <summary>
        /// Define the compile unit to use for code generation.
        /// </summary>
        CodeCompileUnit targetUnit;

        /// <summary>
        /// The only class in the compile unit. This class contains 2 fields,
        /// 3 properties, a constructor, an entry point, and 1 simple method.
        /// </summary>
        CodeTypeDeclaration targetClass;

        /// <summary>
        /// The name of the file to contain the source code.
        /// </summary>
        private const string outputFileName = "SampleCode.cs";

        /// <summary>
        /// Define the class.
        /// </summary>
        public Sample()
        {
            targetUnit = new CodeCompileUnit();
            CodeNamespace samples = new CodeNamespace("CodeDOMSample");
            samples.Imports.Add(new CodeNamespaceImport("System"));
            targetClass = new CodeTypeDeclaration("CodeDOMCreatedClass");
            targetClass.IsClass = true;
            targetClass.TypeAttributes =
                TypeAttributes.Public | TypeAttributes.Sealed;
            samples.Types.Add(targetClass);
            targetUnit.Namespaces.Add(samples);
        }

        /// <summary>
        /// Adds two fields to the class.
        /// </summary>
        public void AddFields()
        {
            // Declare the widthValue field.
            CodeMemberField widthValueField = new CodeMemberField();
            widthValueField.Attributes = MemberAttributes.Private;
            widthValueField.Name = "widthValue";
            widthValueField.Type = new CodeTypeReference(typeof(System.Double));
            widthValueField.Comments.Add(new CodeCommentStatement(
                "The width of the object."));
            targetClass.Members.Add(widthValueField);

            // Declare the heightValue field
            CodeMemberField heightValueField = new CodeMemberField();
            heightValueField.Attributes = MemberAttributes.Private;
            heightValueField.Name = "heightValue";
            heightValueField.Type =
                new CodeTypeReference(typeof(System.Double));
            heightValueField.Comments.Add(new CodeCommentStatement(
                "The height of the object."));
            targetClass.Members.Add(heightValueField);
        }
        /// <summary>
        /// Add three properties to the class.
        /// </summary>
        public void AddProperties()
        {
            // Declare the read-only Width property.
            CodeMemberProperty widthProperty = new CodeMemberProperty();
            widthProperty.Attributes =
                MemberAttributes.Public | MemberAttributes.Final;
            widthProperty.Name = "Width";
            widthProperty.HasGet = true;
            widthProperty.Type = new CodeTypeReference(typeof(System.Double));
            widthProperty.Comments.Add(new CodeCommentStatement(
                "The Width property for the object."));
            widthProperty.GetStatements.Add(new CodeMethodReturnStatement(
                new CodeFieldReferenceExpression(
                new CodeThisReferenceExpression(), "widthValue")));
            targetClass.Members.Add(widthProperty);

            // Declare the read-only Height property.
            CodeMemberProperty heightProperty = new CodeMemberProperty();
            heightProperty.Attributes =
                MemberAttributes.Public | MemberAttributes.Final;
            heightProperty.Name = "Height";
            heightProperty.HasGet = true;
            heightProperty.Type = new CodeTypeReference(typeof(System.Double));
            heightProperty.Comments.Add(new CodeCommentStatement(
                "The Height property for the object."));
            heightProperty.GetStatements.Add(new CodeMethodReturnStatement(
                new CodeFieldReferenceExpression(
                new CodeThisReferenceExpression(), "heightValue")));
            targetClass.Members.Add(heightProperty);

            // Declare the read only Area property.
            CodeMemberProperty areaProperty = new CodeMemberProperty();
            areaProperty.Attributes =
                MemberAttributes.Public | MemberAttributes.Final;
            areaProperty.Name = "Area";
            areaProperty.HasGet = true;
            areaProperty.Type = new CodeTypeReference(typeof(System.Double));
            areaProperty.Comments.Add(new CodeCommentStatement(
                "The Area property for the object."));

            // Create an expression to calculate the area for the get accessor
            // of the Area property.
            CodeBinaryOperatorExpression areaExpression =
                new CodeBinaryOperatorExpression(
                new CodeFieldReferenceExpression(
                new CodeThisReferenceExpression(), "widthValue"),
                CodeBinaryOperatorType.Multiply,
                new CodeFieldReferenceExpression(
                new CodeThisReferenceExpression(), "heightValue"));
            areaProperty.GetStatements.Add(
                new CodeMethodReturnStatement(areaExpression));
            targetClass.Members.Add(areaProperty);
        }

        /// <summary>
        /// Adds a method to the class. This method multiplies values stored
        /// in both fields.
        /// </summary>
        public void AddMethod()
        {
            // Declaring a ToString method
            CodeMemberMethod toStringMethod = new CodeMemberMethod();
            toStringMethod.Attributes =
                MemberAttributes.Public | MemberAttributes.Override;
            toStringMethod.Name = "ToString";
            toStringMethod.ReturnType =
                new CodeTypeReference(typeof(System.String));

            CodeFieldReferenceExpression widthReference =
                new CodeFieldReferenceExpression(
                new CodeThisReferenceExpression(), "Width");
            CodeFieldReferenceExpression heightReference =
                new CodeFieldReferenceExpression(
                new CodeThisReferenceExpression(), "Height");
            CodeFieldReferenceExpression areaReference =
                new CodeFieldReferenceExpression(
                new CodeThisReferenceExpression(), "Area");

            // Declaring a return statement for method ToString.
            CodeMethodReturnStatement returnStatement =
                new CodeMethodReturnStatement();

            // This statement returns a string representation of the width,
            // height, and area.
            string formattedOutput = "The object:" + Environment.NewLine +
                " width = {0}," + Environment.NewLine +
                " height = {1}," + Environment.NewLine +
                " area = {2}";
            returnStatement.Expression =
                new CodeMethodInvokeExpression(
                new CodeTypeReferenceExpression("System.String"), "Format",
                new CodePrimitiveExpression(formattedOutput),
                widthReference, heightReference, areaReference);
            toStringMethod.Statements.Add(returnStatement);
            targetClass.Members.Add(toStringMethod);
        }
        /// <summary>
        /// Add a constructor to the class.
        /// </summary>
        public void AddConstructor()
        {
            // Declare the constructor
            CodeConstructor constructor = new CodeConstructor();
            constructor.Attributes =
                MemberAttributes.Public | MemberAttributes.Final;

            // Add parameters.
            constructor.Parameters.Add(new CodeParameterDeclarationExpression(
                typeof(System.Double), "width"));
            constructor.Parameters.Add(new CodeParameterDeclarationExpression(
                typeof(System.Double), "height"));

            // Add field initialization logic
            CodeFieldReferenceExpression widthReference =
                new CodeFieldReferenceExpression(
                new CodeThisReferenceExpression(), "widthValue");
            constructor.Statements.Add(new CodeAssignStatement(widthReference,
                new CodeArgumentReferenceExpression("width")));
            CodeFieldReferenceExpression heightReference =
                new CodeFieldReferenceExpression(
                new CodeThisReferenceExpression(), "heightValue");
            constructor.Statements.Add(new CodeAssignStatement(heightReference,
                new CodeArgumentReferenceExpression("height")));
            targetClass.Members.Add(constructor);
        }

        /// <summary>
        /// Add an entry point to the class.
        /// </summary>
        public void AddEntryPoint()
        {
            CodeEntryPointMethod start = new CodeEntryPointMethod();
            CodeObjectCreateExpression objectCreate =
                new CodeObjectCreateExpression(
                new CodeTypeReference("CodeDOMCreatedClass"),
                new CodePrimitiveExpression(5.3),
                new CodePrimitiveExpression(6.9));

            // Add the statement:
            // "CodeDOMCreatedClass testClass =
            //     new CodeDOMCreatedClass(5.3, 6.9);"
            start.Statements.Add(new CodeVariableDeclarationStatement(
                new CodeTypeReference("CodeDOMCreatedClass"), "testClass",
                objectCreate));

            // Creat the expression:
            // "testClass.ToString()"
            CodeMethodInvokeExpression toStringInvoke =
                new CodeMethodInvokeExpression(
                new CodeVariableReferenceExpression("testClass"), "ToString");

            // Add a System.Console.WriteLine statement with the previous
            // expression as a parameter.
            start.Statements.Add(new CodeMethodInvokeExpression(
                new CodeTypeReferenceExpression("System.Console"),
                "WriteLine", toStringInvoke));
            targetClass.Members.Add(start);
        }
        /// <summary>
        /// Generate CSharp source code from the compile unit.
        /// </summary>
        /// <param name="filename">Output file name</param>
        public void GenerateCSharpCode(string fileName)
        {
            CodeDomProvider provider = CodeDomProvider.CreateProvider("CSharp");
            CodeGeneratorOptions options = new CodeGeneratorOptions();
            options.BracingStyle = "C";
            using (StreamWriter sourceWriter = new StreamWriter(fileName))
            {
                provider.GenerateCodeFromCompileUnit(
                    targetUnit, sourceWriter, options);
            }
        }

        /// <summary>
        /// Create the CodeDOM graph and generate the code.
        /// </summary>
        static void Main()
        {
            Sample sample = new Sample();
            sample.AddFields();
            sample.AddProperties();
            sample.AddMethod();
            sample.AddConstructor();
            sample.AddEntryPoint();
            sample.GenerateCSharpCode(outputFileName);
        }
    }
}

Imports System.Reflection
Imports System.IO
Imports System.CodeDom
Imports System.CodeDom.Compiler

' This code example creates a graph using a CodeCompileUnit and  
' generates source code for the graph using the VBCodeProvider.
Class Sample

    ' Define the compile unit to use for code generation. 
    Private targetUnit As CodeCompileUnit

    ' The only class in the compile unit. This class contains 2 fields,
    ' 3 properties, a constructor, an entry point, and 1 simple method. 
    Private targetClass As CodeTypeDeclaration

    ' The name of the file to contain the source code.
    Private Const outputFileName As String = "SampleCode.vb"

    ' Define the class.
    Public Sub New()
        targetUnit = New CodeCompileUnit()
        Dim samples As New CodeNamespace("CodeDOMSample")
        samples.Imports.Add(New CodeNamespaceImport("System"))
        targetClass = New CodeTypeDeclaration("CodeDOMCreatedClass")
        targetClass.IsClass = True
        targetClass.TypeAttributes = _
            TypeAttributes.Public Or TypeAttributes.Sealed
        samples.Types.Add(targetClass)
        targetUnit.Namespaces.Add(samples)

    End Sub

    ' Adds two fields to the class.
    Public Sub AddFields()
        ' Declare the widthValue field.
        Dim widthValueField As New CodeMemberField()
        widthValueField.Attributes = MemberAttributes.Private
        widthValueField.Name = "widthValue"
        widthValueField.Type = _
            New CodeTypeReference(GetType(System.Double))
        widthValueField.Comments.Add(New CodeCommentStatement( _
            "The width of the object."))
        targetClass.Members.Add(widthValueField)

        ' Declare the heightValue field
        Dim heightValueField As New CodeMemberField()
        heightValueField.Attributes = MemberAttributes.Private
        heightValueField.Name = "heightValue"
        heightValueField.Type = _
            New CodeTypeReference(GetType(System.Double))
        heightValueField.Comments.Add(New CodeCommentStatement( _
            "The height of the object."))
        targetClass.Members.Add(heightValueField)

    End Sub

    ' Add three properties to the class.
    Public Sub AddProperties()
        ' Declare the read only Width property.
        Dim widthProperty As New CodeMemberProperty()
        widthProperty.Attributes = _
            MemberAttributes.Public Or MemberAttributes.Final
        widthProperty.Name = "Width"
        widthProperty.HasGet = True
        widthProperty.Type = New CodeTypeReference(GetType(System.Double))
        widthProperty.Comments.Add(New CodeCommentStatement( _
            "The width property for the object."))
        widthProperty.GetStatements.Add(New CodeMethodReturnStatement( _
            New CodeFieldReferenceExpression( _
            New CodeThisReferenceExpression(), "widthValue")))
        targetClass.Members.Add(widthProperty)

        ' Declare the read-only Height property.
        Dim heightProperty As New CodeMemberProperty()
        heightProperty.Attributes = _
            MemberAttributes.Public Or MemberAttributes.Final
        heightProperty.Name = "Height"
        heightProperty.HasGet = True
        heightProperty.Type = New CodeTypeReference(GetType(System.Double))
        heightProperty.Comments.Add(New CodeCommentStatement( _
            "The Height property for the object."))
        heightProperty.GetStatements.Add(New CodeMethodReturnStatement( _
            New CodeFieldReferenceExpression( _
            New CodeThisReferenceExpression(), "heightValue")))
        targetClass.Members.Add(heightProperty)

        ' Declare the read only Area property.
        Dim areaProperty As New CodeMemberProperty()
        areaProperty.Attributes = _
            MemberAttributes.Public Or MemberAttributes.Final
        areaProperty.Name = "Area"
        areaProperty.HasGet = True
        areaProperty.Type = New CodeTypeReference(GetType(System.Double))
        areaProperty.Comments.Add(New CodeCommentStatement( _
            "The Area property for the object."))

        ' Create an expression to calculate the area for the get accessor
        ' of the Area property.
        Dim areaExpression As New CodeBinaryOperatorExpression( _
            New CodeFieldReferenceExpression( _
            New CodeThisReferenceExpression(), "widthValue"), _
            CodeBinaryOperatorType.Multiply, _
            New CodeFieldReferenceExpression( _
            New CodeThisReferenceExpression(), "heightValue"))
        areaProperty.GetStatements.Add( _
            New CodeMethodReturnStatement(areaExpression))
        targetClass.Members.Add(areaProperty)

    End Sub

    ' Adds a method to the class. This method multiplies values stored 
    ' in both fields.
    Public Sub AddMethod()
        ' Declaring a ToString method.
        Dim toStringMethod As New CodeMemberMethod()
        toStringMethod.Attributes = _
            MemberAttributes.Public Or MemberAttributes.Override
        toStringMethod.Name = "ToString"
        toStringMethod.ReturnType = _
            New CodeTypeReference(GetType(System.String))

        Dim widthReference As New CodeFieldReferenceExpression( _
            New CodeThisReferenceExpression(), "Width")
        Dim heightReference As New CodeFieldReferenceExpression( _
            New CodeThisReferenceExpression(), "Height")
        Dim areaReference As New CodeFieldReferenceExpression( _
            New CodeThisReferenceExpression(), "Area")

        ' Declaring a return statement for method ToString.
        Dim returnStatement As New CodeMethodReturnStatement()

        ' This statement returns a string representation of the width,
        ' height, and area.
        Dim formattedOutput As String = "The object:" & Environment.NewLine _
            & " width = {0}," & Environment.NewLine & " height = {1}," _
            & Environment.NewLine & " area = {2}"
        returnStatement.Expression = New CodeMethodInvokeExpression( _
            New CodeTypeReferenceExpression("System.String"), "Format", _
            New CodePrimitiveExpression(formattedOutput), widthReference, _
            heightReference, areaReference)
        toStringMethod.Statements.Add(returnStatement)
        targetClass.Members.Add(toStringMethod)

    End Sub

    ' Add a constructor to the class.
    Public Sub AddConstructor()
        ' Declare the constructor
        Dim constructor As New CodeConstructor()
        constructor.Attributes = _
            MemberAttributes.Public Or MemberAttributes.Final

        ' Add parameters.
        constructor.Parameters.Add( _
            New CodeParameterDeclarationExpression( _
            GetType(System.Double), "width"))
        constructor.Parameters.Add( _
            New CodeParameterDeclarationExpression( _
            GetType(System.Double), "height"))

        ' Add field initialization logic
        Dim widthReference As New CodeFieldReferenceExpression( _
            New CodeThisReferenceExpression(), "widthValue")
        constructor.Statements.Add(New CodeAssignStatement( _
            widthReference, New CodeArgumentReferenceExpression("width")))
        Dim heightReference As New CodeFieldReferenceExpression( _
            New CodeThisReferenceExpression(), "heightValue")
        constructor.Statements.Add( _
            New CodeAssignStatement(heightReference, _
            New CodeArgumentReferenceExpression("height")))
        targetClass.Members.Add(constructor)

    End Sub

    ' Add an entry point to the class.
    Public Sub AddEntryPoint()
        Dim start As New CodeEntryPointMethod()
        Dim objectCreate As New CodeObjectCreateExpression( _
            New CodeTypeReference("CodeDOMCreatedClass"), _
            New CodePrimitiveExpression(5.3), _
            New CodePrimitiveExpression(6.9))

        ' Add the statement:
        ' "CodeDOMCreatedClass testClass = _
        '     new CodeDOMCreatedClass(5.3, 6.9);"
        start.Statements.Add(New CodeVariableDeclarationStatement( _
            New CodeTypeReference("CodeDOMCreatedClass"), _
            "testClass", objectCreate))

        ' Creat the expression:
        ' "testClass.ToString()"
        Dim toStringInvoke As New CodeMethodInvokeExpression( _
            New CodeVariableReferenceExpression("testClass"), "ToString")

        ' Add a System.Console.WriteLine statement with the previous 
        ' expression as a parameter.
        start.Statements.Add(New CodeMethodInvokeExpression( _
            New CodeTypeReferenceExpression("System.Console"), _
            "WriteLine", toStringInvoke))
        targetClass.Members.Add(start)

    End Sub

    ' Generate Visual Basic source code from the compile unit.
    Public Sub GenerateVBCode(ByVal fileName As String)
        Dim provider As CodeDomProvider
        provider = CodeDomProvider.CreateProvider("VisualBasic")
        Dim options As New CodeGeneratorOptions()
        Dim sourceWriter As New StreamWriter(fileName)
        Try
            provider.GenerateCodeFromCompileUnit( _
                targetUnit, sourceWriter, options)
        Finally
            sourceWriter.Dispose()
        End Try

    End Sub

    ' Create the CodeDOM graph and generate the code.
    Shared Sub Main()
        Dim sample As New Sample()
        sample.AddFields()
        sample.AddProperties()
        sample.AddMethod()
        sample.AddConstructor()
        sample.AddEntryPoint()
        sample.GenerateVBCode(outputFileName)

    End Sub
End Class

编译和执行以上示例后，会生成以下源代码。

//--------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:2.0.50727.42
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//--------------------------------------------------------------------------

namespace CodeDOMSample
{
    using System;


    public sealed class CodeDOMCreatedClass
    {

        // The width of the object.
        private double widthValue;

        // The height of the object.
        private double heightValue;

        public CodeDOMCreatedClass(double width, double height)
        {
            this.widthValue = width;
            this.heightValue = height;
        }

        // The Width property for the object.
        public double Width
        {
            get
            {
                return this.widthValue;
            }
        }

        // The Height property for the object.
        public double Height
        {
            get
            {
                return this.heightValue;
            }
        }

        // The Area property for the object.
        public double Area
        {
            get
            {
                return (this.widthValue * this.heightValue);
            }
        }

        public override string ToString()
        {
            return string.Format(
                "The object:\r\n width = {0},\r\n height = {1},\r\n area = {2}",
                this.Width, this.Height, this.Area);
        }

        public static void Main()
        {
            CodeDOMCreatedClass testClass = new CodeDOMCreatedClass(5.3, 6.9);
            System.Console.WriteLine(testClass.ToString());
        }
    }
}

'--------------------------------------------------------------------------
' <auto-generated>
'     This code was generated by a tool.
'     Runtime Version:2.0.50727.42
'
'     Changes to this file may cause incorrect behavior and will be lost if
'     the code is regenerated.
' </auto-generated>
'--------------------------------------------------------------------------

Option Strict Off
Option Explicit On

Namespace CodeDOMSample
    
    Public NotInheritable Class CodeDOMCreatedClass
        
        'The width of the object.
        Private widthValue As Double
        
        'The height of the object.
        Private heightValue As Double
        
        Public Sub New(ByVal width As Double, ByVal height As Double)
            MyBase.New
            Me.widthValue = width
            Me.heightValue = height
        End Sub
        
        'The width property for the object.
        Public ReadOnly Property Width() As Double
            Get
                Return Me.widthValue
            End Get
        End Property
        
        'The Height property for the object.
        Public ReadOnly Property Height() As Double
            Get
                Return Me.heightValue
            End Get
        End Property
        
        'The Area property for the object.
        Public ReadOnly Property Area() As Double
            Get
                Return (Me.widthValue * Me.heightValue)
            End Get
        End Property
        
        Public Overrides Function ToString() As String
            Return String.Format("The object:"& _
                Global.Microsoft.VisualBasic.ChrW(13)& _
                Global.Microsoft.VisualBasic.ChrW(10)& _
                " width = {0},"&Global.Microsoft.VisualBasic.ChrW(13)& _
                Global.Microsoft.VisualBasic.ChrW(10)& _
                " height = {1},"&Global.Microsoft.VisualBasic.ChrW(13)& _
                Global.Microsoft.VisualBasic.ChrW(10)&" area = {2}", _
                Me.Width, Me.Height, Me.Area)
        End Function
        
        Public Shared Sub Main()
            Dim testClass As CodeDOMCreatedClass = _
                New CodeDOMCreatedClass(5.3, 6.9)
            System.Console.WriteLine(testClass.ToString)
        End Sub
    End Class
End Namespace

生成的源代码经过编译和执行后会产生以下输出。

The object:
 width = 5.3,
 height = 6.9,
 area = 36.57

编译代码

需要 FullTrust 权限集才可成功执行此代码示例。