CodeTypeParameter Class
Definition
Important
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Represents a type parameter of a generic type or method.
public ref class CodeTypeParameter : System::CodeDom::CodeObjectpublic class CodeTypeParameter : System.CodeDom.CodeObject[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDispatch)]
[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public class CodeTypeParameter : System.CodeDom.CodeObjecttype CodeTypeParameter = class
inherit CodeObject[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDispatch)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
[<System.Serializable>]
type CodeTypeParameter = class
inherit CodeObjectPublic Class CodeTypeParameter
Inherits CodeObject- Inheritance
- Attributes
Examples
The following code example shows the use of the CodeTypeParameter class to create a CodeDOM graph to generate an application containing generics code.
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
Remarks
The CodeTypeParameter class represents a type parameter in the declaration of a generic type or method.
A generic type or method declaration contains one or more unspecified types known as type parameters. A type parameter name stands for the type within the body of the generic declaration. For example, the generic declaration for the List<T> class contains the type parameter T.
For more information on generics, see Generics in the .NET Framework Class Library.
Constructors
| CodeTypeParameter() |
Initializes a new instance of the CodeTypeParameter class. |
| CodeTypeParameter(String) |
Initializes a new instance of the CodeTypeParameter class with the specified type parameter name. |
Properties
| Constraints |
Gets the constraints for the type parameter. |
| CustomAttributes |
Gets the custom attributes of the type parameter. |
| HasConstructorConstraint |
Gets or sets a value indicating whether the type parameter has a constructor constraint. |
| Name |
Gets or sets the name of the type parameter. |
| UserData |
Gets the user-definable data for the current object. (Inherited from CodeObject) |
Methods
| Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
| GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| ToString() |
Returns a string that represents the current object. (Inherited from Object) |
