MethodInfo.MakeGenericMethod(Type[]) Méthode

Définition

Substitue les éléments d'un tableau de types aux paramètres de type de la définition de méthode générique actuelle et retourne un objet MethodInfo représentant la méthode construite résultante.Substitutes the elements of an array of types for the type parameters of the current generic method definition, and returns a MethodInfo object representing the resulting constructed method.

public:
 virtual System::Reflection::MethodInfo ^ MakeGenericMethod(... cli::array <Type ^> ^ typeArguments);
public virtual System.Reflection.MethodInfo MakeGenericMethod (params Type[] typeArguments);
abstract member MakeGenericMethod : Type[] -> System.Reflection.MethodInfo
override this.MakeGenericMethod : Type[] -> System.Reflection.MethodInfo
Public Overridable Function MakeGenericMethod (ParamArray typeArguments As Type()) As MethodInfo

Paramètres

typeArguments
Type[]

Tableau de types à substituer aux paramètres de type de la définition de méthode générique actuelle.An array of types to be substituted for the type parameters of the current generic method definition.

Retours

Objet MethodInfo qui représente la méthode construite formée en substituant les éléments de typeArguments aux les paramètres de type de la définition de méthode générique actuelle.A MethodInfo object that represents the constructed method formed by substituting the elements of typeArguments for the type parameters of the current generic method definition.

Exceptions

Le MethodInfo actuel ne représente pas une définition de méthode générique.The current MethodInfo does not represent a generic method definition. Autrement dit, IsGenericMethodDefinition retourne false.That is, IsGenericMethodDefinition returns false.

typeArguments est null.typeArguments is null.

- ou --or- Tout élément de typeArguments est null.Any element of typeArguments is null.

Le nombre d'éléments contenus dans typeArguments n'est pas identique au nombre de paramètres de type dans la définition de méthode générique actuelle.The number of elements in typeArguments is not the same as the number of type parameters of the current generic method definition.

- ou --or- Un élément de typeArguments ne satisfait pas les contraintes spécifiées pour le paramètre de type correspondant de la définition de méthode générique actuelle.An element of typeArguments does not satisfy the constraints specified for the corresponding type parameter of the current generic method definition.

Cette méthode n'est pas prise en charge.This method is not supported.

Exemples

L’exemple de code suivant illustre les propriétés et les MethodInfo méthodes de qui prennent en charge l’examen des méthodes génériques.The following code example demonstrates the properties and methods of MethodInfo that support the examination of generic methods. L’exemple effectue les opérations suivantes :The example does the following:

  • Définit une classe qui a une méthode générique.Defines a class that has a generic method.

  • Crée un MethodInfo qui représente la méthode générique.Creates a MethodInfo that represents the generic method.

  • Affiche les propriétés de la définition de méthode générique.Displays properties of the generic method definition.

  • Assigne des arguments de type aux paramètres de type MethodInfodu et appelle la méthode générique construite résultante.Assigns type arguments to the type parameters of the MethodInfo, and invokes the resulting constructed generic method.

  • Affiche les propriétés de la méthode générique construite.Displays properties of the constructed generic method.

  • Récupère la définition de méthode générique à partir de la méthode construite et la compare à la définition d’origine.Retrieves the generic method definition from the constructed method and compares it to the original definition.

using namespace System;
using namespace System::Reflection;

// Define a class with a generic method.
ref class Example
{
public:
    generic<typename T> static void Generic(T toDisplay)
    {
        Console::WriteLine("\r\nHere it is: {0}", toDisplay);
    }
};

void DisplayGenericMethodInfo(MethodInfo^ mi)
{
    Console::WriteLine("\r\n{0}", mi);

    Console::WriteLine("\tIs this a generic method definition? {0}", 
        mi->IsGenericMethodDefinition);

    Console::WriteLine("\tIs it a generic method? {0}", 
        mi->IsGenericMethod);

    Console::WriteLine("\tDoes it have unassigned generic parameters? {0}", 
        mi->ContainsGenericParameters);

    // If this is a generic method, display its type arguments.
    //
    if (mi->IsGenericMethod)
    {
        array<Type^>^ typeArguments = mi->GetGenericArguments();

        Console::WriteLine("\tList type arguments ({0}):", 
            typeArguments->Length);

        for each (Type^ tParam in typeArguments)
        {
            // IsGenericParameter is true only for generic type
            // parameters.
            //
            if (tParam->IsGenericParameter)
            {
                Console::WriteLine("\t\t{0}  parameter position {1}" +
                    "\n\t\t   declaring method: {2}",
                    tParam,
                    tParam->GenericParameterPosition,
                    tParam->DeclaringMethod);
            }
            else
            {
                Console::WriteLine("\t\t{0}", tParam);
            }
        }
    }
};

void main()
{
    Console::WriteLine("\r\n--- Examine a generic method.");

    // Create a Type object representing class Example, and
    // get a MethodInfo representing the generic method.
    //
    Type^ ex = Example::typeid;
    MethodInfo^ mi = ex->GetMethod("Generic");

    DisplayGenericMethodInfo(mi);

    // Assign the int type to the type parameter of the Example 
    // method.
    //
    MethodInfo^ miConstructed = mi->MakeGenericMethod(int::typeid);

    DisplayGenericMethodInfo(miConstructed);

    // Invoke the method.
    array<Object^>^ args = { 42 };
    miConstructed->Invoke((Object^) 0, args);

    // Invoke the method normally.
    Example::Generic<int>(42);

    // Get the generic type definition from the closed method,
    // and show it's the same as the original definition.
    //
    MethodInfo^ miDef = miConstructed->GetGenericMethodDefinition();
    Console::WriteLine("\r\nThe definition is the same: {0}",
            miDef == mi);
};
        
/* This example produces the following output:

--- Examine a generic method.

Void Generic[T](T)
        Is this a generic method definition? True
        Is it a generic method? True
        Does it have unassigned generic parameters? True
        List type arguments (1):
                T  parameter position 0
                   declaring method: Void Generic[T](T)

Void Generic[Int32](Int32)
        Is this a generic method definition? False
        Is it a generic method? True
        Does it have unassigned generic parameters? False
        List type arguments (1):
                System.Int32

Here it is: 42

Here it is: 42

The definition is the same: True

 */
using System;
using System.Reflection;

// Define a class with a generic method.
public class Example
{
    public static void Generic<T>(T toDisplay)
    {
        Console.WriteLine("\r\nHere it is: {0}", toDisplay);
    }
}

public class Test
{
    public static void Main()
    {
        Console.WriteLine("\r\n--- Examine a generic method.");

        // Create a Type object representing class Example, and
        // get a MethodInfo representing the generic method.
        //
        Type ex = typeof(Example);
        MethodInfo mi = ex.GetMethod("Generic");

        DisplayGenericMethodInfo(mi);

        // Assign the int type to the type parameter of the Example 
        // method.
        //
        MethodInfo miConstructed = mi.MakeGenericMethod(typeof(int));

        DisplayGenericMethodInfo(miConstructed);

        // Invoke the method.
        object[] args = {42};
        miConstructed.Invoke(null, args);

        // Invoke the method normally.
        Example.Generic<int>(42);

        // Get the generic type definition from the closed method,
        // and show it's the same as the original definition.
        //
        MethodInfo miDef = miConstructed.GetGenericMethodDefinition();
        Console.WriteLine("\r\nThe definition is the same: {0}",
            miDef == mi);
    }
        
    private static void DisplayGenericMethodInfo(MethodInfo mi)
    {
        Console.WriteLine("\r\n{0}", mi);

        Console.WriteLine("\tIs this a generic method definition? {0}", 
            mi.IsGenericMethodDefinition);

        Console.WriteLine("\tIs it a generic method? {0}", 
            mi.IsGenericMethod);

        Console.WriteLine("\tDoes it have unassigned generic parameters? {0}", 
            mi.ContainsGenericParameters);

        // If this is a generic method, display its type arguments.
        //
        if (mi.IsGenericMethod)
        {
            Type[] typeArguments = mi.GetGenericArguments();

            Console.WriteLine("\tList type arguments ({0}):", 
                typeArguments.Length);

            foreach (Type tParam in typeArguments)
            {
                // IsGenericParameter is true only for generic type
                // parameters.
                //
                if (tParam.IsGenericParameter)
                {
                    Console.WriteLine("\t\t{0}  parameter position {1}" +
                        "\n\t\t   declaring method: {2}",
                        tParam,
                        tParam.GenericParameterPosition,
                        tParam.DeclaringMethod);
                }
                else
                {
                    Console.WriteLine("\t\t{0}", tParam);
                }
            }
        }
    }
}

/* This example produces the following output:

--- Examine a generic method.

Void Generic[T](T)
        Is this a generic method definition? True
        Is it a generic method? True
        Does it have unassigned generic parameters? True
        List type arguments (1):
                T  parameter position 0
                   declaring method: Void Generic[T](T)

Void Generic[Int32](Int32)
        Is this a generic method definition? False
        Is it a generic method? True
        Does it have unassigned generic parameters? False
        List type arguments (1):
                System.Int32

Here it is: 42

Here it is: 42

The definition is the same: True

 */
Imports System.Reflection

' Define a class with a generic method.
Public Class Example
    Public Shared Sub Generic(Of T)(ByVal toDisplay As T)
        Console.WriteLine(vbCrLf & "Here it is: {0}", toDisplay)
    End Sub
End Class

Public Class Test
    Public Shared Sub Main() 
        Console.WriteLine(vbCrLf & "--- Examine a generic method.")
        
        ' Create a Type object representing class Example, and
        ' get a MethodInfo representing the generic method.
        '
        Dim ex As Type = GetType(Example)
        Dim mi As MethodInfo = ex.GetMethod("Generic")
        
        DisplayGenericMethodInfo(mi)
        
        ' Assign the Integer type to the type parameter of the Example 
        ' method.
        '
        Dim arguments() As Type = { GetType(Integer) }
        Dim miConstructed As MethodInfo = mi.MakeGenericMethod(arguments)
        
        DisplayGenericMethodInfo(miConstructed)

        ' Invoke the method.
        Dim args() As Object = { 42 }
        miConstructed.Invoke(Nothing, args)
        
        ' Invoke the method normally.
        Example.Generic(Of Integer)(42)
        
        ' Get the generic type definition from the constructed method,
        ' and show that it's the same as the original definition.
        '
        Dim miDef As MethodInfo = miConstructed.GetGenericMethodDefinition()
        Console.WriteLine(vbCrLf & "The definition is the same: {0}", _
            miDef Is mi)
    End Sub
      
    Private Shared Sub DisplayGenericMethodInfo(ByVal mi As MethodInfo) 
        Console.WriteLine(vbCrLf & mi.ToString())
        
        Console.WriteLine(vbTab _
            & "Is this a generic method definition? {0}", _
            mi.IsGenericMethodDefinition)

        Console.WriteLine(vbTab & "Is it a generic method? {0}", _
            mi.IsGenericMethod)

        Console.WriteLine(vbTab _
            & "Does it have unassigned generic parameters? {0}", _
            mi.ContainsGenericParameters)

        ' If this is a generic method, display its type arguments.
        '
        If mi.IsGenericMethod Then
            Dim typeArguments As Type() = mi.GetGenericArguments()
            
            Console.WriteLine(vbTab & "List type arguments ({0}):", _
                typeArguments.Length)
            
            For Each tParam As Type In typeArguments
                ' IsGenericParameter is true only for generic type
                ' parameters.
                '
                If tParam.IsGenericParameter Then
                    Console.WriteLine(vbTab & vbTab _
                        & "{0}  parameter position: {1}" _
                        & vbCrLf & vbTab & vbTab _
                        & "   declaring method: {2}", _
                        tParam,  _
                        tParam.GenericParameterPosition, _
                        tParam.DeclaringMethod)
                Else
                    Console.WriteLine(vbTab & vbTab & tParam.ToString())
                End If
            Next tParam
        End If
    End Sub 
End Class 

' This example produces the following output:
'
'--- Examine a generic method.
'
'Void Generic[T](T)
'        Is this a generic method definition? True
'        Is it a generic method? True
'        Does it have unassigned generic parameters? True
'        List type arguments (1):
'                T  parameter position: 0
'                   declaring method: Void Generic[T](T)
'
'Void Generic[Int32](Int32)
'        Is this a generic method definition? False
'        Is it a generic method? True
'        Does it have unassigned generic parameters? False
'        List type arguments (1):
'                System.Int32
'
'Here it is: 42
'
'Here it is: 42
'
'The definition is the same: True
'

Remarques

La MakeGenericMethod méthode vous permet d’écrire du code qui assigne des types spécifiques aux paramètres de type d’une définition de méthode générique, MethodInfo créant ainsi un objet qui représente une méthode construite particulière.The MakeGenericMethod method allows you to write code that assigns specific types to the type parameters of a generic method definition, thus creating a MethodInfo object that represents a particular constructed method. Si la ContainsGenericParameters propriété de cet MethodInfo objet retourne true, vous pouvez l’utiliser pour appeler la méthode ou pour créer un délégué pour appeler la méthode.If the ContainsGenericParameters property of this MethodInfo object returns true, you can use it to invoke the method or to create a delegate to invoke the method.

Les méthodes construites MakeGenericMethod avec la méthode peuvent être ouvertes, autrement dit, certains de leurs arguments de type peuvent être des paramètres de type de types génériques englobants.Methods constructed with the MakeGenericMethod method can be open, that is, some of their type arguments can be type parameters of enclosing generic types. Vous pouvez utiliser ces méthodes construites ouvertes lorsque vous générez des assemblys dynamiques.You might use such open constructed methods when you generate dynamic assemblies. Par exemple, considérez les C#éléments suivants, Visual Basic C++ et code.For example, consider the following C#, Visual Basic, and C++ code.

class C  
{  
    T N<T,U>(T t, U u) {...}  
    public V M<V>(V v)  
    {  
        return N<V,int>(v, 42);  
    }  
}  
  
Class C  
    Public Function N(Of T,U)(ByVal ta As T, ByVal ua As U) As T  
        ...  
    End Function  
    Public Function M(Of V)(ByVal va As V ) As V  
        Return N(Of V, Integer)(va, 42)  
    End Function  
End Class  
  
ref class C  
{  
private:  
    generic <typename T, typename U> T N(T t, U u) {...}  
public:  
    generic <typename V> V M(V v)  
    {  
        return N<V, int>(v, 42);  
    }  
};  

Le corps de méthode M de contient un appel à Nla méthode, en spécifiant M le paramètre de Int32type de et le type.The method body of M contains a call to method N, specifying the type parameter of M and the type Int32. La IsGenericMethodDefinition propriété retourne false pour la N<V,int>méthode.The IsGenericMethodDefinition property returns false for method N<V,int>. La ContainsGenericParameters propriété retourne true, par conséquent N<V,int> , la méthode ne peut pas être appelée.The ContainsGenericParameters property returns true, so method N<V,int> cannot be invoked.

Pour obtenir la liste des conditions invariantes pour les termes spécifiques aux méthodes génériques, IsGenericMethod consultez la propriété.For a list of the invariant conditions for terms specific to generic methods, see the IsGenericMethod property. Pour obtenir la liste des conditions invariantes pour les autres termes utilisés dans la réflexion générique IsGenericType , consultez la propriété.For a list of the invariant conditions for other terms used in generic reflection, see the IsGenericType property.

S’applique à

Voir aussi