Gör så här: Skapa en klass med Hjälp av CodeDOM

Följande procedurer visar hur du skapar och kompilerar ett CodeDOM-diagram som genererar en klass som innehåller två fält, tre egenskaper, en metod, en konstruktor och en startpunkt.

1. Skapa ett konsolprogram som ska använda CodeDOM-kod för att generera källkoden för en klass.

   I det här exemplet heter Sampleden genererande klassen och den genererade koden är en klass med namnet CodeDOMCreatedClass i en fil med namnet SampleCode.

2. I den genererande klassen initierar du CodeDOM-grafen och använder CodeDOM-metoder för att definiera medlemmarna, konstruktorn och startpunkten (Main metoden) för den genererade klassen.

   I det här exemplet har den genererade klassen två fält, tre egenskaper, en konstruktor, en metod och en Main metod.

3. I den genererande klassen skapar du en språkspecifik kodprovider och anropar dess GenerateCodeFromCompileUnit metod för att generera koden från diagrammet.

4. Kompilera och kör programmet för att generera koden.

   I det här exemplet finns den genererade koden i en fil med namnet SampleCode. Kompilera och kör koden för att se exempelutdata.

Skapa programmet som ska köra CodeDOM-koden

Skapa en konsolprogramklass som ska innehålla CodeDOM-koden. Definiera de globala fält som ska användas i klassen för att referera till sammansättningen (CodeCompileUnit) och klassen (CodeTypeDeclaration), ange namnet på den genererade källfilen och deklarera Main metoden.

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

Initiera CodeDOM-grafen

I konstruktorn för konsolprogramklassen initierar du sammansättningen och klassen och lägger till lämpliga deklarationer i CodeDOM-grafen.

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

Lägga till medlemmar i CodeDOM-grafen

• Lägg till fält i CodeDOM-grafen genom att lägga till CodeMemberField objekt i Members klassens egenskap.

  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
  

• Lägg till egenskaper i CodeDOM-grafen genom att lägga till CodeMemberProperty objekt i Members klassens egenskap.

  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
  

• Lägg till en metod i CodeDOM-grafen genom att lägga till ett CodeMemberMethod objekt i Members -egenskapen för klassen.

  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
  

• Lägg till en konstruktor i CodeDOM-grafen genom att lägga till ett CodeConstructor objekt i Members -egenskapen för klassen.

  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
  

• Lägg till en startpunkt i CodeDOM-grafen genom att lägga till ett CodeEntryPointMethod objekt i Members -egenskapen för klassen.

  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
  

Generera koden från CodeDOM-grafen

Generera källkod från CodeDOM-grafen GenerateCodeFromCompileUnit genom att anropa metoden.

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

Skapa grafen och generera koden

1. Lägg till de metoder som skapades i föregående steg i metoden Main som definierades i det första steget.

   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
   

2. Kompilera och köra genereringsklassen.

Exempel

I följande kodexempel visas koden från föregående steg.

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

När föregående exempel kompileras och körs genererar det följande källkod.

//--------------------------------------------------------------------------
// <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

Den genererade källkoden genererar följande utdata när den kompileras och körs.

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

Kompilera koden

• Det här kodexemplet kräver att behörighetsuppsättningen FullTrust körs korrekt.

Se även

• Använda CodeDOM
• Generera och kompilera källkod från ett CodeDOM Graph