CodeTypeParameter Classe

Définition

Espace de noms:

System.CodeDom

Assembly:

System.CodeDom.dll

Paquet:

System.CodeDom v8.0.0

Source:

CodeTypeParameter.cs

Représente un paramètre de type d'un type ou d'une méthode générique.

public ref class CodeTypeParameter : System::CodeDom::CodeObject

public class CodeTypeParameter : System.CodeDom.CodeObject

type CodeTypeParameter = class
    inherit CodeObject

Public Class CodeTypeParameter
Inherits CodeObject

Héritage

Object

CodeObject

CodeTypeParameter

Exemples

L’exemple de code suivant montre l’utilisation de la CodeTypeParameter classe pour créer un graphe CodeDOM afin de générer une application contenant du code générique.

using System.CodeDom;
using System.CodeDom.Compiler;
using System.Collections;
using System.Collections.Specialized;
using System.IO;
using System.Reflection;
using System.Text.RegularExpressions;
using System.Globalization;
using System.Collections.Generic;
namespace System.CodeDom
{
    class CodeDomGenericsDemo
    {
        static void Main()
        {
            try
            {
                CreateGenericsCode("cs", "Generic.cs", "GenericCS.exe");
            }
            catch (Exception e)
            {
                LogMessage("Unexpected Exception:" + e.ToString());
            }
        }

        static void CreateGenericsCode(string providerName, string sourceFileName, string assemblyName)
        {

            CodeDomProvider provider = CodeDomProvider.CreateProvider(providerName);

            LogMessage("Building CodeDOM graph...");

            CodeCompileUnit cu = new CodeCompileUnit();

            CreateGraph(provider, cu);

            StringWriter sw = new StringWriter();

            LogMessage("Generating code...");
            provider.GenerateCodeFromCompileUnit(cu, sw, null);

            string output = sw.ToString();
            output = Regex.Replace(output, "Runtime Version:[^\r\n]*",
                "Runtime Version omitted for demo");

            LogMessage("Dumping source...");
            LogMessage(output);

            LogMessage("Writing source to file...");
            Stream s = File.Open(sourceFileName, FileMode.Create);
            StreamWriter t = new StreamWriter(s);
            t.Write(output);
            t.Close();
            s.Close();

            CompilerParameters opt = new CompilerParameters(new string[]{
                                      "System.dll",
                                      "System.Xml.dll",
                                      "System.Windows.Forms.dll",
                                      "System.Data.dll",
                                      "System.Drawing.dll"});
            opt.GenerateExecutable = false;
            opt.TreatWarningsAsErrors = true;
            opt.IncludeDebugInformation = true;
            opt.GenerateInMemory = true;

            CompilerResults results;

            LogMessage("Compiling with " + providerName);
            results = provider.CompileAssemblyFromFile(opt, sourceFileName);

            OutputResults(results);
            if (results.NativeCompilerReturnValue != 0)
            {
                LogMessage("");
                LogMessage("Compilation failed.");
            }
            else
            {
                LogMessage("");
                LogMessage("Demo completed successfully.");
            }
            File.Delete(sourceFileName);
        }

        // Create a CodeDOM graph.
        static void CreateGraph(CodeDomProvider provider, CodeCompileUnit cu)
        {
            if (!provider.Supports(GeneratorSupport.GenericTypeReference |
               GeneratorSupport.GenericTypeDeclaration))
            {
                // Return if the generator does not support generics.
                return;
            }

            CodeNamespace ns = new CodeNamespace("DemoNamespace");
            ns.Imports.Add(new CodeNamespaceImport("System"));
            ns.Imports.Add(new CodeNamespaceImport("System.Collections.Generic"));
            cu.Namespaces.Add(ns);

            // Declare a generic class.
            CodeTypeDeclaration class1 = new CodeTypeDeclaration();
            class1.Name = "MyDictionary";
            class1.BaseTypes.Add(new CodeTypeReference("Dictionary",
                                      new CodeTypeReference[] {
                                          new CodeTypeReference("TKey"),
                                          new CodeTypeReference("TValue"),
                                     }));
            CodeTypeParameter kType = new CodeTypeParameter("TKey");
            kType.HasConstructorConstraint = true;
            kType.Constraints.Add(new CodeTypeReference(typeof(IComparable)));
            kType.CustomAttributes.Add(new CodeAttributeDeclaration(
                "System.ComponentModel.DescriptionAttribute",
                    new CodeAttributeArgument(new CodePrimitiveExpression("KeyType"))));

            CodeTypeReference iComparableT = new CodeTypeReference("IComparable");
            iComparableT.TypeArguments.Add(new CodeTypeReference(kType));

            kType.Constraints.Add(iComparableT);

            CodeTypeParameter vType = new CodeTypeParameter("TValue");
            vType.Constraints.Add(new CodeTypeReference(typeof(IList<System.String>)));
            vType.CustomAttributes.Add(new CodeAttributeDeclaration(
                "System.ComponentModel.DescriptionAttribute",
                    new CodeAttributeArgument(new CodePrimitiveExpression("ValueType"))));

            class1.TypeParameters.Add(kType);
            class1.TypeParameters.Add(vType);

            ns.Types.Add(class1);

            // Declare a generic method.
            CodeMemberMethod printMethod = new CodeMemberMethod();
            CodeTypeParameter sType = new CodeTypeParameter("S");
            sType.HasConstructorConstraint = true;
            CodeTypeParameter tType = new CodeTypeParameter("T");
            sType.HasConstructorConstraint = true;

            printMethod.Name = "Print";
            printMethod.TypeParameters.Add(sType);
            printMethod.TypeParameters.Add(tType);

            printMethod.Statements.Add(ConsoleWriteLineStatement(
                new CodeDefaultValueExpression(new CodeTypeReference("T"))));
            printMethod.Statements.Add(ConsoleWriteLineStatement(
                new CodeDefaultValueExpression(new CodeTypeReference("S"))));

            printMethod.Attributes = MemberAttributes.Public;
            class1.Members.Add(printMethod);

            CodeTypeDeclaration class2 = new CodeTypeDeclaration();
            class2.Name = "Demo";

            CodeEntryPointMethod methodMain = new CodeEntryPointMethod();

            CodeTypeReference myClass = new CodeTypeReference(
                "MyDictionary",
                new CodeTypeReference[] {
                    new CodeTypeReference(typeof(int)),
                    new CodeTypeReference("List",
                       new CodeTypeReference[]
                            {new CodeTypeReference("System.String") })});

            methodMain.Statements.Add(
                  new CodeVariableDeclarationStatement(myClass,
                      "dict",
                          new CodeObjectCreateExpression(myClass)));

            methodMain.Statements.Add(ConsoleWriteLineStatement(
                new CodePropertyReferenceExpression(
                      new CodeVariableReferenceExpression("dict"),
                            "Count")));

            methodMain.Statements.Add(new CodeExpressionStatement(
                 new CodeMethodInvokeExpression(
                      new CodeMethodReferenceExpression(
                         new CodeVariableReferenceExpression("dict"),
                             "Print",
                                 new CodeTypeReference[] {
                                    new CodeTypeReference("System.Decimal"),
                                       new CodeTypeReference("System.Int32"),}),
                                           new CodeExpression[0])));

            string dictionaryTypeName = typeof(System.Collections.Generic.Dictionary<int,
                System.Collections.Generic.List<string>>[]).FullName;

            CodeTypeReference dictionaryType = new CodeTypeReference(dictionaryTypeName);
            methodMain.Statements.Add(
                  new CodeVariableDeclarationStatement(dictionaryType, "dict2",
                     new CodeArrayCreateExpression(dictionaryType, new CodeExpression[1] { new CodePrimitiveExpression(null) })));

            methodMain.Statements.Add(ConsoleWriteLineStatement(
                           new CodePropertyReferenceExpression(
                                new CodeVariableReferenceExpression("dict2"),
                                        "Length")));

            class2.Members.Add(methodMain);
            ns.Types.Add(class2);
        }

        static CodeStatement ConsoleWriteLineStatement(CodeExpression exp)
        {
            return new CodeExpressionStatement(
                new CodeMethodInvokeExpression(
                   new CodeMethodReferenceExpression(
                       new CodeTypeReferenceExpression(new CodeTypeReference("Console")),
                           "WriteLine"),
                               new CodeExpression[]{
                                   exp,
                                     }));
        }

        static CodeStatement ConsoleWriteLineStatement(string text)
        {
            return ConsoleWriteLineStatement(new CodePrimitiveExpression(text));
        }
        static void LogMessage(string text)
        {
            Console.WriteLine(text);
        }

        static void OutputResults(CompilerResults results)
        {
            LogMessage("NativeCompilerReturnValue=" +
                results.NativeCompilerReturnValue.ToString());
            foreach (string s in results.Output)
            {
                LogMessage(s);
            }
        }
    }
}
// This example generates the following code:
//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version omitted for demo
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

//namespace DemoNamespace
//{
//    using System;
//    using System.Collections.Generic;


//    public class MyDictionary<[System.ComponentModel.DescriptionAttribute("KeyType")]  TKey,
//          [System.ComponentModel.DescriptionAttribute("ValueType")]  TValue> : Dictionary<TKey, TValue>
//        where TKey : System.IComparable, IComparable<TKey>, new()
//        where TValue : System.Collections.Generic.IList<string>
//    {

//        public virtual void Print<S, T>()
//            where S : new()
//        {
//            Console.WriteLine(default(T));
//            Console.WriteLine(default(S));
//        }
//    }

//    public class Demo
//    {

//        public static void Main()
//        {
//            MyDictionary<int, List<string>> dict = new MyDictionary<int, List<string>>();
//            Console.WriteLine(dict.Count);
//            dict.Print<decimal, int>();
//            System.Collections.Generic.Dictionary<int, System.Collections.Generic.List<string>>[] dict2 =
//              new System.Collections.Generic.Dictionary<int, System.Collections.Generic.List<string>>[] { null };
//            Console.WriteLine(dict2.Length);
//        }
//    }
//}

Imports System.CodeDom
Imports System.CodeDom.Compiler
Imports System.Collections
Imports System.Collections.Specialized
Imports System.IO
Imports System.Reflection
Imports System.Text.RegularExpressions
Imports System.Globalization
Imports System.Collections.Generic


Class CodeDomGenericsDemo

    Shared Sub Main()
        Try
            CreateGenericsCode("vb", "Generic.vb", "GenericVB.exe")
        Catch e As Exception
            LogMessage(("Unexpected Exception:" + e.ToString()))
        End Try

    End Sub


    Shared Sub CreateGenericsCode(ByVal providerName As String, ByVal sourceFileName As String, ByVal assemblyName As String)

        Dim provider As CodeDomProvider = CodeDomProvider.CreateProvider(providerName)

        LogMessage("Building CodeDOM graph...")

        Dim cu As New CodeCompileUnit()

        CreateGraph(provider, cu)

        Dim sw As New StringWriter()

        LogMessage("Generating code...")
        provider.GenerateCodeFromCompileUnit(cu, sw, Nothing)

        Dim output As String = sw.ToString()
        output = Regex.Replace(output, "Runtime version:[^" + vbCr + vbLf + "]*", "Runtime version omitted for demo")

        LogMessage("Displaying source code...")
        LogMessage(output)

        LogMessage("Writing source code to file...")
        Dim s As Stream = File.Open(sourceFileName, FileMode.Create)
        Dim t As New StreamWriter(s)
        t.Write(output)
        t.Close()
        s.Close()

        Dim opt As New CompilerParameters(New String() {"System.dll", "System.Xml.dll", "System.Windows.Forms.dll", "System.Data.dll", "System.Drawing.dll"})
        opt.GenerateExecutable = False
        opt.TreatWarningsAsErrors = True
        opt.IncludeDebugInformation = True
        opt.GenerateInMemory = True

        Dim results As CompilerResults

        LogMessage(("Compiling with provider " + providerName))
        results = provider.CompileAssemblyFromFile(opt, sourceFileName)

        OutputResults(results)
        If results.NativeCompilerReturnValue <> 0 Then
            LogMessage("")
            LogMessage("Compilation failed.")
        Else
            LogMessage("")
            LogMessage("Demo completed successfully.")
        End If
        File.Delete(sourceFileName)

    End Sub


    ' Create a CodeDOM graph.
    Shared Sub CreateGraph(ByVal provider As CodeDomProvider, ByVal cu As CodeCompileUnit)
        ' Determine if the generator supports generics.
        If Not provider.Supports(GeneratorSupport.GenericTypeReference Or GeneratorSupport.GenericTypeDeclaration) Then
            ' Return if the generator does not support generics.
            Return
        End If
        Dim ns As New CodeNamespace("DemoNamespace")
        ns.Imports.Add(New CodeNamespaceImport("System"))
        ns.Imports.Add(New CodeNamespaceImport("System.Collections.Generic"))
        cu.Namespaces.Add(ns)

        ' Declare a generic class.
        Dim class1 As New CodeTypeDeclaration()
        class1.Name = "MyDictionary"
        class1.BaseTypes.Add( _
            New CodeTypeReference("Dictionary", _
                New CodeTypeReference() {New CodeTypeReference("TKey"), _
                    New CodeTypeReference("TValue")}))
        Dim kType As New CodeTypeParameter("TKey")
        kType.HasConstructorConstraint = True
        kType.Constraints.Add(New CodeTypeReference(GetType(IComparable)))
        kType.CustomAttributes.Add _
            (New CodeAttributeDeclaration("System.ComponentModel.DescriptionAttribute", _
                New CodeAttributeArgument(New CodePrimitiveExpression("KeyType"))))
        Dim iComparableT As New CodeTypeReference("IComparable")
        iComparableT.TypeArguments.Add(New CodeTypeReference(kType))

        kType.Constraints.Add(iComparableT)

        Dim vType As New CodeTypeParameter("TValue")
        vType.Constraints.Add(New CodeTypeReference(GetType(IList(Of System.String))))
        vType.CustomAttributes.Add _
            (New CodeAttributeDeclaration("System.ComponentModel.DescriptionAttribute", _
                New CodeAttributeArgument(New CodePrimitiveExpression("ValueType"))))

        class1.TypeParameters.Add(kType)
        class1.TypeParameters.Add(vType)
        ns.Types.Add(class1)

        ' Declare a generic method.
        Dim printMethod As New CodeMemberMethod()
        Dim sType As New CodeTypeParameter("S")
        sType.HasConstructorConstraint = True
        Dim tType As New CodeTypeParameter("T")
        tType.HasConstructorConstraint = True

        printMethod.Name = "Print"
        printMethod.TypeParameters.Add(sType)
        printMethod.TypeParameters.Add(tType)

        printMethod.Statements.Add(ConsoleWriteLineStatement _
            (New CodeDefaultValueExpression(New CodeTypeReference("T"))))
        printMethod.Statements.Add(ConsoleWriteLineStatement _
            (New CodeDefaultValueExpression(New CodeTypeReference("S"))))
        printMethod.Attributes = MemberAttributes.Public
        class1.Members.Add(printMethod)

        Dim class2 As New CodeTypeDeclaration()
        class2.Name = "Demo"

        Dim methodMain As New CodeEntryPointMethod()

        Dim [myClass] As New CodeTypeReference("MyDictionary", _
            New CodeTypeReference() {New CodeTypeReference(GetType(Integer)), _
                New CodeTypeReference("List", _
                    New CodeTypeReference() {New CodeTypeReference("System.String")})})

        methodMain.Statements.Add(New CodeVariableDeclarationStatement([myClass], _
            "dict", New CodeObjectCreateExpression([myClass])))

        methodMain.Statements.Add(ConsoleWriteLineStatement _
            (New CodePropertyReferenceExpression _
                (New CodeVariableReferenceExpression("dict"), "Count")))

        methodMain.Statements.Add _
            (New CodeExpressionStatement _
                (New CodeMethodInvokeExpression _
                    (New CodeMethodReferenceExpression _
                        (New CodeVariableReferenceExpression("dict"), _
                            "Print", New CodeTypeReference() _
                                    {New CodeTypeReference("System.Decimal"), _
                                        New CodeTypeReference("System.Int32")}), _
                                            New CodeExpression(-1) {})))
        Dim longTypeName As String = GetType( _
            System.Collections.Generic.Dictionary(Of Integer, _
                System.Collections.Generic.List(Of String))()).FullName

        Dim longType As New CodeTypeReference(longTypeName)

        methodMain.Statements.Add(New CodeVariableDeclarationStatement _
            (longType, "dict2", New CodeArrayCreateExpression _
                (longType, New CodeExpression(0) {New CodePrimitiveExpression(Nothing)})))

        methodMain.Statements.Add(ConsoleWriteLineStatement(New CodePropertyReferenceExpression(New CodeVariableReferenceExpression("dict2"), "Length")))

        class2.Members.Add(methodMain)
        ns.Types.Add(class2)

    End Sub


    Overloads Shared Function ConsoleWriteLineStatement(ByVal exp As CodeExpression) As CodeStatement
        Return New CodeExpressionStatement(New CodeMethodInvokeExpression _
            (New CodeMethodReferenceExpression _
                (New CodeTypeReferenceExpression _
                    (New CodeTypeReference("Console")), "WriteLine"), _
                        New CodeExpression() {exp}))

    End Function 'ConsoleWriteLineStatement


    Overloads Shared Function ConsoleWriteLineStatement(ByVal [text] As String) As CodeStatement
        Return ConsoleWriteLineStatement(New CodePrimitiveExpression([text]))

    End Function 'ConsoleWriteLineStatement

    Shared Sub LogMessage(ByVal [text] As String)
        Console.WriteLine([text])

    End Sub


    Shared Sub OutputResults(ByVal results As CompilerResults)
        LogMessage(("NativeCompilerReturnValue=" + results.NativeCompilerReturnValue.ToString()))
        Dim s As String
        For Each s In results.Output
            LogMessage(s)
        Next s

    End Sub
End Class
'
' This example generates the following code:
'------------------------------------------------------------------------------
' <auto-generated>
'     This code was generated by a tool.
'     Runtime Version:2.0.50727.1434
'
'     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

''Imports System.Collections.Generic

'Namespace DemoNamespace

'    Public Class MyDictionary(Of TKey As  {System.IComparable, IComparable(Of TKey), New}, TValue As System.Collections.
'Generic.IList(Of String))
'        Inherits Dictionary(Of TKey, TValue)

'        Public Overridable Sub Print(Of S As New, T As New)()
'            Console.WriteLine(CType(Nothing, T))
'            Console.WriteLine(CType(Nothing, S))
'        End Sub
'    End Class

'    Public Class Demo

'        Public Shared Sub Main()
'            Dim dict As MyDictionary(Of Integer, List(Of String)) = New MyDictionary(Of Integer, List(Of String))
'            Console.WriteLine(dict.Count)
'            dict.Print(Of Decimal, Integer)()
'            Dim dict2() As System.Collections.Generic.Dictionary(Of Integer, System.Collections.Generic.List(Of String))
' = New System.Collections.Generic.Dictionary(Of Integer, System.Collections.Generic.List(Of String))() {Nothing}
'            Console.WriteLine(dict2.Length)
'        End Sub
'    End Class
'End Namespace

Remarques

La CodeTypeParameter classe représente un paramètre de type dans la déclaration d’une méthode ou d’un type générique.

Une déclaration de type ou de méthode générique contient un ou plusieurs types non spécifiés appelés paramètres de type. Un nom de paramètre de type correspond au type dans le corps de la déclaration générique. Par exemple, la déclaration générique de la List<T> classe contient le paramètre de Ttype .

Pour plus d’informations sur les génériques, consultez Génériques dans la bibliothèque de classes .NET Framework.

Constructeurs

CodeTypeParameter()	Initialise une nouvelle instance de la classe CodeTypeParameter.
CodeTypeParameter(String)	Initialise une nouvelle instance de la classe CodeTypeParameter avec le nom du paramètre de type spécifié.

Propriétés

Constraints	Obtient les contraintes pour le paramètre de type.
CustomAttributes	Obtient les attributs personnalisés du paramètre de type.
HasConstructorConstraint	Obtient ou définit une valeur qui indique si le paramètre de type possède une contrainte de constructeur.
Name	Obtient ou définit le nom du paramètre de type.
UserData	Obtient les données définissables par l'utilisateur pour l'objet en cours. (Hérité de CodeObject)

Méthodes

Equals(Object)	Détermine si l'objet spécifié est égal à l'objet actuel. (Hérité de Object)
GetHashCode()	Fait office de fonction de hachage par défaut. (Hérité de Object)
GetType()	Obtient le Type de l'instance actuelle. (Hérité de Object)
MemberwiseClone()	Crée une copie superficielle du Object actuel. (Hérité de Object)
ToString()	Retourne une chaîne qui représente l'objet actuel. (Hérité de Object)