CodeTypeParameter Klas
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Vertegenwoordigt een typeparameter van een algemeen type of methode.
public ref 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.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- Overname
- Kenmerken
Voorbeelden
In het volgende codevoorbeeld ziet u het gebruik van de CodeTypeParameter klasse om een CodeDOM-grafiek te maken voor het genereren van een toepassing met generieke 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
Opmerkingen
De CodeTypeParameter klasse vertegenwoordigt een typeparameter in de declaratie van een algemeen type of methode.
Een algemene type- of methodedeclaratie bevat een of meer niet-opgegeven typen, ook wel typeparameters genoemd. De naam van een typeparameter staat voor het type in de hoofdtekst van de algemene declaratie. De algemene declaratie voor de List<T> klasse bevat bijvoorbeeld de typeparameter T.
Zie Generics in .NET Framework Class Library voor meer informatie over generics.
Constructors
| Name | Description |
|---|---|
| CodeTypeParameter() |
Initialiseert een nieuw exemplaar van de CodeTypeParameter klasse. |
| CodeTypeParameter(String) |
Initialiseert een nieuw exemplaar van de CodeTypeParameter klasse met de opgegeven parameternaam van het type. |
Eigenschappen
| Name | Description |
|---|---|
| Constraints |
Hiermee haalt u de beperkingen voor de typeparameter op. |
| CustomAttributes |
Hiermee haalt u de aangepaste kenmerken van de typeparameter op. |
| HasConstructorConstraint |
Hiermee wordt een waarde opgehaald of ingesteld die aangeeft of de typeparameter een constructorbeperking heeft. |
| Name |
Hiermee haalt u de naam van de typeparameter op of stelt u deze in. |
| UserData |
Haalt de door de gebruiker gedefinieerde gegevens voor het huidige object op. (Overgenomen van CodeObject) |
Methoden
| Name | Description |
|---|---|
| Equals(Object) |
Bepaalt of het opgegeven object gelijk is aan het huidige object. (Overgenomen van Object) |
| GetHashCode() |
Fungeert als de standaardhashfunctie. (Overgenomen van Object) |
| GetType() |
Hiermee haalt u de Type huidige instantie op. (Overgenomen van Object) |
| MemberwiseClone() |
Hiermee maakt u een ondiepe kopie van de huidige Object. (Overgenomen van Object) |
| ToString() |
Retourneert een tekenreeks die het huidige object vertegenwoordigt. (Overgenomen van Object) |