MethodBuilder.DefineGenericParameters(String[]) Méthode
Définition
Important
Certaines informations portent sur la préversion du produit qui est susceptible d’être en grande partie modifiée avant sa publication. Microsoft exclut toute garantie, expresse ou implicite, concernant les informations fournies ici.
Définit le nombre de paramètres de type générique pour la méthode actuelle, indique leur nom et retourne un tableau d’objets GenericTypeParameterBuilder pouvant être utilisés pour définir leurs contraintes.
public:
cli::array <System::Reflection::Emit::GenericTypeParameterBuilder ^> ^ DefineGenericParameters(... cli::array <System::String ^> ^ names);public System.Reflection.Emit.GenericTypeParameterBuilder[] DefineGenericParameters (params string[] names);member this.DefineGenericParameters : string[] -> System.Reflection.Emit.GenericTypeParameterBuilder[]Public Function DefineGenericParameters (ParamArray names As String()) As GenericTypeParameterBuilder()Paramètres
- names
- String[]
Tableau de chaînes qui représentent les noms des paramètres de type générique.
Retours
Tableau d’objets GenericTypeParameterBuilder représentant les paramètres de type de la méthode générique.
Exceptions
Des paramètres de type générique ont déjà été définis pour cette méthode.
- ou -
La méthode a déjà été exécutée.
- ou -
La méthode SetImplementationFlags(MethodImplAttributes) a été appelée pour la méthode actuelle.
names est un tableau vide.
Exemples
L’exemple de code suivant crée un type dynamique, DemoType, qui contient la méthode DemoMethodgénérique dynamique . Cette méthode a deux paramètres de type génériques, l’un utilisé comme paramètre et l’autre comme type de retour.
Quand le code est exécuté, l’assembly dynamique est enregistré en tant que DemoGenericMethod1.dll, et peut être examiné à l’aide de Ildasm.exe (désassembleur IL).
Notes
Cet exemple de code génère un corps de méthode simple qui retourne simplement une référence null. Pour obtenir un exemple de code avec un corps de méthode plus complet qui crée et utilise des types génériques, consultez How to : Define a Generic Method with Reflection Emit.
using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
public ref class GenericReflectionSample
{
};
int main()
{
// Creating a dynamic assembly requires an AssemblyName
// object, and the current application domain.
//
AssemblyName^ asmName =
gcnew AssemblyName("EmittedAssembly");
AppDomain^ domain = AppDomain::CurrentDomain;
AssemblyBuilder^ sampleAssemblyBuilder =
domain->DefineDynamicAssembly(asmName,
AssemblyBuilderAccess::RunAndSave);
// Define the module that contains the code. For an
// assembly with one module, the module name is the
// assembly name plus a file extension.
ModuleBuilder^ sampleModuleBuilder =
sampleAssemblyBuilder->DefineDynamicModule(asmName->Name,
asmName->Name + ".dll");
TypeBuilder^ sampleTypeBuilder =
sampleModuleBuilder->DefineType("SampleType",
TypeAttributes::Public | TypeAttributes::Abstract);
// Define a Shared, Public method with standard calling
// conventions. Do not specify the parameter types or the
// return type, because type parameters will be used for
// those types, and the type parameters have not been
// defined yet.
MethodBuilder^ sampleMethodBuilder =
sampleTypeBuilder->DefineMethod("SampleMethod",
MethodAttributes::Public | MethodAttributes::Static);
// Defining generic parameters for the method makes it a
// generic method. By convention, type parameters are
// single alphabetic characters. T and U are used here.
//
array<String^>^ genericTypeNames = {"T", "U"};
array<GenericTypeParameterBuilder^>^ genericTypes =
sampleMethodBuilder->DefineGenericParameters(
genericTypeNames);
// Use the IsGenericMethod property to find out if a
// dynamic method is generic, and IsGenericMethodDefinition
// to find out if it defines a generic method.
Console::WriteLine("Is SampleMethod generic? {0}",
sampleMethodBuilder->IsGenericMethod);
Console::WriteLine(
"Is SampleMethod a generic method definition? {0}",
sampleMethodBuilder->IsGenericMethodDefinition);
// Set parameter types for the method. The method takes
// one parameter, and its type is specified by the first
// type parameter, T.
array<Type^>^ parameterTypes = {genericTypes[0]};
sampleMethodBuilder->SetParameters(parameterTypes);
// Set the return type for the method. The return type is
// specified by the second type parameter, U.
sampleMethodBuilder->SetReturnType(genericTypes[1]);
// Generate a code body for the method. The method doesn't
// do anything except return null.
//
ILGenerator^ ilgen = sampleMethodBuilder->GetILGenerator();
ilgen->Emit(OpCodes::Ldnull);
ilgen->Emit(OpCodes::Ret);
// Complete the type.
Type^ sampleType = sampleTypeBuilder->CreateType();
// To bind types to a dynamic generic method, you must
// first call the GetMethod method on the completed type.
// You can then define an array of types, and bind them
// to the method.
MethodInfo^ sampleMethodInfo = sampleType->GetMethod("SampleMethod");
array<Type^>^ boundParameters =
{String::typeid, GenericReflectionSample::typeid};
MethodInfo^ boundMethodInfo =
sampleMethodInfo->MakeGenericMethod(boundParameters);
// Display a string representing the bound method.
Console::WriteLine(boundMethodInfo);
// Save the assembly, so it can be examined with Ildasm.exe.
sampleAssemblyBuilder->Save(asmName->Name + ".dll");
}
/* This code example produces the following output:
Is SampleMethod generic? True
Is SampleMethod a generic method definition? True
GenericReflectionSample SampleMethod[String,GenericReflectionSample](System.String)
*/
using System;
using System.Reflection;
using System.Reflection.Emit;
class DemoMethodBuilder
{
public static void Main()
{
// Creating a dynamic assembly requires an AssemblyName
// object, and the current application domain.
//
AssemblyName asmName =
new AssemblyName("DemoMethodBuilder1");
AppDomain domain = AppDomain.CurrentDomain;
AssemblyBuilder demoAssembly =
domain.DefineDynamicAssembly(
asmName,
AssemblyBuilderAccess.RunAndSave
);
// Define the module that contains the code. For an
// assembly with one module, the module name is the
// assembly name plus a file extension.
ModuleBuilder demoModule =
demoAssembly.DefineDynamicModule(
asmName.Name,
asmName.Name + ".dll"
);
TypeBuilder demoType = demoModule.DefineType(
"DemoType",
TypeAttributes.Public | TypeAttributes.Abstract
);
// Define a Shared, Public method with standard calling
// conventions. Do not specify the parameter types or the
// return type, because type parameters will be used for
// those types, and the type parameters have not been
// defined yet.
MethodBuilder demoMethod = demoType.DefineMethod(
"DemoMethod",
MethodAttributes.Public | MethodAttributes.Static
);
// Defining generic parameters for the method makes it a
// generic method. By convention, type parameters are
// single alphabetic characters. T and U are used here.
//
string[] typeParamNames = {"T", "U"};
GenericTypeParameterBuilder[] typeParameters =
demoMethod.DefineGenericParameters(typeParamNames);
// The second type parameter is constrained to be a
// reference type.
typeParameters[1].SetGenericParameterAttributes(
GenericParameterAttributes.ReferenceTypeConstraint);
// Use the IsGenericMethod property to find out if a
// dynamic method is generic, and IsGenericMethodDefinition
// to find out if it defines a generic method.
Console.WriteLine("Is DemoMethod generic? {0}",
demoMethod.IsGenericMethod);
Console.WriteLine("Is DemoMethod a generic method definition? {0}",
demoMethod.IsGenericMethodDefinition);
// Set parameter types for the method. The method takes
// one parameter, and its type is specified by the first
// type parameter, T.
Type[] parms = {typeParameters[0]};
demoMethod.SetParameters(parms);
// Set the return type for the method. The return type is
// specified by the second type parameter, U.
demoMethod.SetReturnType(typeParameters[1]);
// Generate a code body for the method. The method doesn't
// do anything except return null.
//
ILGenerator ilgen = demoMethod.GetILGenerator();
ilgen.Emit(OpCodes.Ldnull);
ilgen.Emit(OpCodes.Ret);
// Complete the type.
Type dt = demoType.CreateType();
// To bind types to a dynamic generic method, you must
// first call the GetMethod method on the completed type.
// You can then define an array of types, and bind them
// to the method.
MethodInfo m = dt.GetMethod("DemoMethod");
Type[] typeArgs = {typeof(string), typeof(DemoMethodBuilder)};
MethodInfo bound = m.MakeGenericMethod(typeArgs);
// Display a string representing the bound method.
Console.WriteLine(bound);
// Save the assembly, so it can be examined with Ildasm.exe.
demoAssembly.Save(asmName.Name + ".dll");
}
}
/* This code example produces the following output:
Is DemoMethod generic? True
Is DemoMethod a generic method definition? True
DemoMethodBuilder DemoMethod[String,DemoMethodBuilder](System.String)
*/
Imports System.Reflection
Imports System.Reflection.Emit
Class DemoMethodBuilder
Public Shared Sub Main()
' Creating a dynamic assembly requires an AssemblyName
' object, and the current application domain.
'
Dim asmName As New AssemblyName("DemoMethodBuilder1")
Dim domain As AppDomain = AppDomain.CurrentDomain
Dim demoAssembly As AssemblyBuilder = _
domain.DefineDynamicAssembly(asmName, _
AssemblyBuilderAccess.RunAndSave)
' Define the module that contains the code. For an
' assembly with one module, the module name is the
' assembly name plus a file extension.
Dim demoModule As ModuleBuilder = _
demoAssembly.DefineDynamicModule( _
asmName.Name, _
asmName.Name & ".dll")
Dim demoType As TypeBuilder = demoModule.DefineType( _
"DemoType", _
TypeAttributes.Public Or TypeAttributes.Abstract)
' Define a Shared, Public method with standard calling
' conventions. Do not specify the parameter types or the
' return type, because type parameters will be used for
' those types, and the type parameters have not been
' defined yet.
Dim demoMethod As MethodBuilder = _
demoType.DefineMethod("DemoMethod", _
MethodAttributes.Public Or MethodAttributes.Static)
' Defining generic parameters for the method makes it a
' generic method. By convention, type parameters are
' single alphabetic characters. T and U are used here.
'
Dim typeParamNames() As String = {"T", "U"}
Dim typeParameters() As GenericTypeParameterBuilder = _
demoMethod.DefineGenericParameters(typeParamNames)
' The second type parameter is constrained to be a
' reference type.
typeParameters(1).SetGenericParameterAttributes( _
GenericParameterAttributes.ReferenceTypeConstraint)
' Use the IsGenericMethod property to find out if a
' dynamic method is generic, and IsGenericMethodDefinition
' to find out if it defines a generic method.
Console.WriteLine("Is DemoMethod generic? {0}", _
demoMethod.IsGenericMethod)
Console.WriteLine("Is DemoMethod a generic method definition? {0}", _
demoMethod.IsGenericMethodDefinition)
' Set parameter types for the method. The method takes
' one parameter, and its type is specified by the first
' type parameter, T.
Dim params() As Type = {typeParameters(0)}
demoMethod.SetParameters(params)
' Set the return type for the method. The return type is
' specified by the second type parameter, U.
demoMethod.SetReturnType(typeParameters(1))
' Generate a code body for the method. The method doesn't
' do anything except return Nothing.
'
Dim ilgen As ILGenerator = demoMethod.GetILGenerator()
ilgen.Emit(OpCodes.Ldnull)
ilgen.Emit(OpCodes.Ret)
' Complete the type.
Dim dt As Type = demoType.CreateType()
' To bind types to a dynamic generic method, you must
' first call the GetMethod method on the completed type.
' You can then define an array of types, and bind them
' to the method.
Dim m As MethodInfo = dt.GetMethod("DemoMethod")
Dim typeArgs() As Type = _
{GetType(String), GetType(DemoMethodBuilder)}
Dim bound As MethodInfo = m.MakeGenericMethod(typeArgs)
' Display a string representing the bound method.
Console.WriteLine(bound)
' Save the assembly, so it can be examined with Ildasm.exe.
demoAssembly.Save(asmName.Name & ".dll")
End Sub
End Class
' This code example produces the following output:
'Is DemoMethod generic? True
'Is DemoMethod a generic method definition? True
'DemoMethodBuilder DemoMethod[String,DemoMethodBuilder](System.String)
Remarques
L’appel de la DefineGenericParameters méthode rend la méthode actuelle générique. Il n’existe aucun moyen d’annuler cette modification. L’appel de cette méthode une deuxième fois provoque un InvalidOperationException.
Les paramètres de type de la méthode générique peuvent être récupérés ultérieurement à l’aide de la GetGenericArguments méthode .
Par convention, un nom de paramètre de type est une seule lettre majuscule.
Pour plus d’informations, consultez MethodBase.IsGenericMethod et MethodInfo.GetGenericMethodDefinition. Pour plus d’informations sur les types génériques, consultez Type.IsGenericType.
S’applique à
Voir aussi
Collaborer avec nous sur GitHub
La source de ce contenu se trouve sur GitHub, où vous pouvez également créer et examiner les problèmes et les demandes de tirage. Pour plus d’informations, consultez notre guide du contributeur.
