TypeBuilder.CreateType 方法
定義
重要
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建立這個類別的 Type 物件。 定義類別上的欄位和方法之後，呼叫 CreateType 以載入其 Type 物件。
public:
Type ^ CreateType();public Type? CreateType ();public Type CreateType ();member this.CreateType : unit -> TypePublic Function CreateType () As Type傳回
傳回這個類別的新 Type 物件。
例外狀況
在 ILGenerator 中有錯誤的標籤內容：您已定義標籤，但未呼叫 MarkLabel(Label)。
這個類型包含無效的 Microsoft Intermediate Language (MSIL) 程式碼。
-或-
使用 1 個位元組位移指定分支目標，但目標與分支的距離大於 127 個位元組。
無法載入這個類型。 例如，其包含的 static 方法具有呼叫慣例 HasThis。
範例
下列程式代碼範例示範如何定義 事件的事件處理程式AppDomain.TypeResolve，以便在封入型別的呼叫期間CreateType，在巢狀類型上呼叫 CreateType 方法。
using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
using namespace System::Threading;
using namespace System::Text;
using namespace System::Resources;
using namespace System::Collections;
using namespace System::IO;
// Helper class called when a resolve type event is raised.
ref class TypeResolveHandler
{
private:
Module^ m_Module;
public:
TypeResolveHandler( Module^ mod )
{
m_Module = mod;
}
Assembly^ ResolveEvent( Object^ sender, ResolveEventArgs^ args );
};
ref class NestedEnum
{
internal:
static TypeBuilder^ enumType = nullptr;
static Type^ tNested = nullptr;
static Type^ tNesting = nullptr;
public:
static void Main()
{
AssemblyName^ asmName = gcnew AssemblyName;
asmName->Name = "NestedEnum";
AssemblyBuilder^ asmBuild = Thread::GetDomain()->DefineDynamicAssembly( asmName, AssemblyBuilderAccess::RunAndSave );
ModuleBuilder^ modBuild = asmBuild->DefineDynamicModule( "ModuleOne", "NestedEnum.dll" );
// Hook up the event listening.
TypeResolveHandler^ typeResolveHandler = gcnew TypeResolveHandler( modBuild );
// Add a listener for the type resolve events.
AppDomain^ currentDomain = Thread::GetDomain();
ResolveEventHandler^ resolveHandler = gcnew ResolveEventHandler( typeResolveHandler, &TypeResolveHandler::ResolveEvent );
currentDomain->TypeResolve += resolveHandler;
TypeBuilder^ tb = modBuild->DefineType( "AType", TypeAttributes::Public );
TypeBuilder^ eb = tb->DefineNestedType( "AnEnum", static_cast<TypeAttributes>(TypeAttributes::NestedPublic | TypeAttributes::Sealed), Enum::typeid, 0 );
eb->DefineField( "value__", int::typeid, static_cast<FieldAttributes>(FieldAttributes::Private | FieldAttributes::SpecialName) );
FieldBuilder^ fb = eb->DefineField( "Field1", eb, static_cast<FieldAttributes>(FieldAttributes::Public | FieldAttributes::Literal | FieldAttributes::Static) );
fb->SetConstant( 1 );
enumType = eb;
// Comment out this field.
// When this field is defined, the loader cannot determine the size
// of the type. Therefore, a TypeResolve event is generated when the
// nested type is completed.
tb->DefineField( "Field2", eb, FieldAttributes::Public );
tNesting = tb->CreateType();
if ( tNesting == nullptr )
Console::WriteLine( "NestingType CreateType failed but didn't throw!" );
try
{
tNested = eb->CreateType();
if ( tNested == nullptr )
Console::WriteLine( "NestedType CreateType failed but didn't throw!" );
}
catch ( Exception^ )
{
// This is needed because you might have already completed the type in the TypeResolve event.
}
if ( tNested != nullptr )
{
Type^ x = tNested->DeclaringType;
if ( x == nullptr )
Console::WriteLine( "Declaring type is null." );
else
Console::WriteLine( x->Name );
}
asmBuild->Save( "NestedEnum.dll" );
// Remove the listener for the type resolve events.
currentDomain->TypeResolve -= resolveHandler;
}
};
Assembly^ TypeResolveHandler::ResolveEvent( Object^ sender, ResolveEventArgs^ args )
{
Console::WriteLine( args->Name );
// Use args.Name to look up the type name. In this case, you are getting AnEnum.
try
{
NestedEnum::tNested = NestedEnum::enumType->CreateType();
}
catch ( Exception^ )
{
// This is needed to throw away InvalidOperationException.
// Loader might send the TypeResolve event more than once
// and the type might be complete already.
}
// Complete the type.
return m_Module->Assembly;
}
int main()
{
NestedEnum::Main();
}
using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Threading;
using System.Text;
using System.Resources;
using System.Collections;
using System.IO;
internal class NestedEnum {
internal static TypeBuilder enumType = null;
internal static Type tNested = null;
internal static Type tNesting = null;
public static void Main(String[] args) {
AssemblyName asmName = new AssemblyName();
asmName.Name = "NestedEnum";
AssemblyBuilder asmBuild = Thread.GetDomain().DefineDynamicAssembly(asmName, AssemblyBuilderAccess.RunAndSave);
ModuleBuilder modBuild = asmBuild.DefineDynamicModule("ModuleOne", "NestedEnum.dll");
// Hook up the event listening.
TypeResolveHandler typeResolveHandler = new TypeResolveHandler(modBuild);
// Add a listener for the type resolve events.
AppDomain currentDomain = Thread.GetDomain();
ResolveEventHandler resolveHandler = new ResolveEventHandler(typeResolveHandler.ResolveEvent);
currentDomain.TypeResolve += resolveHandler;
TypeBuilder tb = modBuild.DefineType("AType", TypeAttributes.Public);
TypeBuilder eb = tb.DefineNestedType("AnEnum", TypeAttributes.NestedPublic | TypeAttributes.Sealed, typeof(Enum), null);
eb.DefineField("value__", typeof(int), FieldAttributes.Private | FieldAttributes.SpecialName);
FieldBuilder fb = eb.DefineField("Field1", eb, FieldAttributes.Public | FieldAttributes.Literal | FieldAttributes.Static);
fb.SetConstant(1);
enumType = eb;
// Comment out this field.
// When this field is defined, the loader cannot determine the size
// of the type. Therefore, a TypeResolve event is generated when the
// nested type is completed.
tb.DefineField("Field2", eb, FieldAttributes.Public);
tNesting = tb.CreateType();
if (tNesting == null)
Console.WriteLine("NestingType CreateType failed but didn't throw!");
try {
tNested = eb.CreateType();
if (tNested == null)
Console.WriteLine("NestedType CreateType failed but didn't throw!");
}
catch {
// This is needed because you might have already completed the type in the TypeResolve event.
}
if (tNested != null) {
Type x = tNested.DeclaringType;
if (x == null)
Console.WriteLine("Declaring type was null.");
else
Console.WriteLine(x.Name);
}
asmBuild.Save( "NestedEnum.dll" );
// Remove the listener for the type resolve events.
currentDomain.TypeResolve -= resolveHandler;
}
}
// Helper class called when a resolve type event is raised.
internal class TypeResolveHandler
{
private Module m_Module;
public TypeResolveHandler(Module mod)
{
m_Module = mod;
}
public Assembly ResolveEvent(Object sender, ResolveEventArgs args)
{
Console.WriteLine(args.Name);
// Use args.Name to look up the type name. In this case, you are getting AnEnum.
try {
NestedEnum.tNested = NestedEnum.enumType.CreateType();
}
catch {
// This is needed to throw away InvalidOperationException.
// Loader might send the TypeResolve event more than once
// and the type might be complete already.
}
// Complete the type.
return m_Module.Assembly;
}
}
Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Threading
Imports System.Text
Imports System.Resources
Imports System.Collections
Imports System.IO
Friend Class NestedEnum
Friend Shared enumType As TypeBuilder = Nothing
Friend Shared tNested As Type = Nothing
Friend Shared tNesting As Type = Nothing
Public Shared Sub Main()
Dim asmName As New AssemblyName()
asmName.Name = "NestedEnum"
Dim asmBuild As AssemblyBuilder = Thread.GetDomain().DefineDynamicAssembly(asmName, AssemblyBuilderAccess.RunAndSave)
Dim modBuild As ModuleBuilder = asmBuild.DefineDynamicModule("ModuleOne", "NestedEnum.dll")
' Hook up the event listening.
Dim typeResolveHandler As New TypeResolveHandler(modBuild)
' Add a listener for the type resolve events.
Dim currentDomain As AppDomain = Thread.GetDomain()
Dim resolveHandler As ResolveEventHandler = AddressOf typeResolveHandler.ResolveEvent
AddHandler currentDomain.TypeResolve, resolveHandler
Dim tb As TypeBuilder = modBuild.DefineType("AType", TypeAttributes.Public)
Dim eb As TypeBuilder = tb.DefineNestedType("AnEnum", TypeAttributes.NestedPublic Or TypeAttributes.Sealed, GetType([Enum]))
eb.DefineField("value__", GetType(Integer), FieldAttributes.Private Or FieldAttributes.SpecialName)
Dim fb As FieldBuilder = eb.DefineField("Field1", eb, FieldAttributes.Public Or FieldAttributes.Literal Or FieldAttributes.Static)
fb.SetConstant(1)
enumType = eb
' Comment out this field.
' When this field is defined, the loader cannot determine the size
' of the type. Therefore, a TypeResolve event is generated when the
' nested type is completed.
tb.DefineField("Field2", eb, FieldAttributes.Public)
tNesting = tb.CreateType()
If tNesting Is Nothing Then
Console.WriteLine("NestingType CreateType failed but didn't throw!")
End If
Try
tNested = eb.CreateType()
If tNested Is Nothing Then
Console.WriteLine("NestedType CreateType failed but didn't throw!")
End If
Catch
End Try ' This is needed because you might have already completed the type in the TypeResolve event.
If Not (tNested Is Nothing) Then
Dim x As Type = tNested.DeclaringType
If x Is Nothing Then
Console.WriteLine("Declaring type is Nothing.")
Else
Console.WriteLine(x.Name)
End If
End If
asmBuild.Save("NestedEnum.dll")
' Remove the listener for the type resolve events.
RemoveHandler currentDomain.TypeResolve, resolveHandler
End Sub
End Class
' Helper class called when a resolve type event is raised.
Friend Class TypeResolveHandler
Private m_Module As [Module]
Public Sub New([mod] As [Module])
m_Module = [mod]
End Sub
Public Function ResolveEvent(sender As [Object], args As ResolveEventArgs) As [Assembly]
Console.WriteLine(args.Name)
' Use args.Name to look up the type name. In this case, you are getting AnEnum.
Try
NestedEnum.tNested = NestedEnum.enumType.CreateType()
Catch
End Try ' This is needed to throw away InvalidOperationException.
' Loader might send the TypeResolve event more than once
' and the type might be complete already.
' Complete the type.
Return m_Module.Assembly
End Function 'ResolveEvent
End Class
備註
如果這個類型是巢狀類型， CreateType 則必須在封入類型上呼叫 方法，才能在巢狀類型上呼叫。
如果目前的型別衍生自不完整的類型或實作不完整的介面，請在父類型上呼叫 CreateType 方法，並在目前類型上呼叫方法。
如果封入類型包含定義為巢狀類型的欄位，例如， (定義為巢狀類型的實值型別，則定義為巢狀類型的欄位) ，則呼叫 CreateType 封入類型上的 方法將會產生 AppDomain.TypeResolve 事件。 這是因為載入器在完成巢狀類型之前，無法判斷封入類型的大小。 呼叫端應該定義 事件的處理程式 TypeResolve ，藉由呼叫 CreateType 代表巢狀類型的 物件來完成 TypeBuilder 巢狀型別的定義。 本主題的程式代碼範例示範如何定義這類事件處理程式。
不論呼叫 方法的次數 CreateType 為何，類型只會建立一次。 所有呼叫都會傳回相同的 Type 物件。
