Type.IsGenericTypeDefinition Eigenschaft

Definition

Ruft einen Wert ab, der angibt, ob der aktuelle Type eine generische Typdefinition darstellt, aus der andere generische Typen konstruiert werden können.Gets a value indicating whether the current Type represents a generic type definition, from which other generic types can be constructed.

public:
 virtual property bool IsGenericTypeDefinition { bool get(); };
public virtual bool IsGenericTypeDefinition { get; }
member this.IsGenericTypeDefinition : bool
Public Overridable ReadOnly Property IsGenericTypeDefinition As Boolean

Eigenschaftswert

true, wenn das Type-Objekt eine generische Typdefinition darstellt, andernfalls false.true if the Type object represents a generic type definition; otherwise, false.

Beispiele

Im folgenden Beispiel werden Informationen zu einem Typ, einschließlich der Angabe, ob es sich um eine generische Typdefinition handelt, angezeigt.The following example displays information about a type, including whether or not it is a generic type definition. Informationen werden für einen konstruierten Typ, für die generische Typdefinition und für einen normalen Typ angezeigt.Information is displayed for a constructed type, for its generic type definition, and for an ordinary type.

using namespace System;
using namespace System::Reflection;
using namespace System::Collections::Generic;

public ref class Test
{
private:
   static void DisplayGenericTypeInfo( Type^ t )
   {
      Console::WriteLine( L"\r\n{0}", t );
      Console::WriteLine( L"\tIs this a generic type definition? {0}",
         t->IsGenericTypeDefinition );
      Console::WriteLine( L"\tIs it a generic type? {0}",
         t->IsGenericType );
      
      if ( t->IsGenericType )
      {
         
         // If this is a generic type, display the type arguments.
         //
         array<Type^>^typeArguments = t->GetGenericArguments();
         Console::WriteLine( L"\tList type arguments ({0}):",
            typeArguments->Length );
         System::Collections::IEnumerator^ myEnum =
            typeArguments->GetEnumerator();
         while ( myEnum->MoveNext() )
         {
            Type^ tParam = safe_cast<Type^>(myEnum->Current);
            
            // If this is a type parameter, display its
            // position.
            //
            if ( tParam->IsGenericParameter )
            {
               Console::WriteLine(
                  L"\t\t{0}\t(unassigned - parameter position {1})",
                  tParam, tParam->GenericParameterPosition );
            }
            else
            {
               Console::WriteLine( L"\t\t{0}", tParam );
            }
         }
      }
   }


public:
   static void Main()
   {
      Console::Write( L"\r\n--- Display information about a " );
      Console::WriteLine( L"constructed type, its" );
      Console::WriteLine( L"    generic type definition, and an ordinary type." );
      
      // Create a Dictionary of Test objects, using strings for the
      // keys.
      Dictionary< String^,Test^ >^ d = gcnew Dictionary< String^,Test^ >;
      
      // Display information for the constructed type and its generic
      // type definition.
      DisplayGenericTypeInfo( d->GetType() );
      DisplayGenericTypeInfo( d->GetType()->GetGenericTypeDefinition() );
      
      // Display information for an ordinary type.
      DisplayGenericTypeInfo( String::typeid );
   }

};

int main()
{
   Test::Main();
}

/* This example produces the following output:

--- Display information about a constructed type, its
    generic type definition, and an ordinary type.

System.Collections.Generic.Dictionary[System.String,Test]
        Is this a generic type definition? False
        Is it a generic type? True
        List type arguments (2):
                System.String
                Test

System.Collections.Generic.Dictionary[TKey,TValue]
        Is this a generic type definition? True
        Is it a generic type? True
        List type arguments (2):
                TKey    (unassigned - parameter position 0)
                TValue  (unassigned - parameter position 1)

System.String
        Is this a generic type definition? False
        Is it a generic type? False
 */
using System;
using System.Reflection;
using System.Collections.Generic;

public class Test
{
    private static void DisplayGenericTypeInfo(Type t)
    {
        Console.WriteLine("\r\n{0}", t);

        Console.WriteLine("\tIs this a generic type definition? {0}", 
            t.IsGenericTypeDefinition);

        Console.WriteLine("\tIs it a generic type? {0}", 
            t.IsGenericType);

        if (t.IsGenericType)
        {
            // If this is a generic type, display the type arguments.
            //
            Type[] typeArguments = t.GetGenericArguments();

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

            foreach (Type tParam in typeArguments)
            {
                // If this is a type parameter, display its
                // position.
                //
                if (tParam.IsGenericParameter)
                {
                    Console.WriteLine("\t\t{0}\t(unassigned - parameter position {1})",
                        tParam,
                        tParam.GenericParameterPosition);
                }
                else
                {
                    Console.WriteLine("\t\t{0}", tParam);
                }
            }
        }
    }

    public static void Main()
    {
        Console.WriteLine("\r\n--- Display information about a constructed type, its");
        Console.WriteLine("    generic type definition, and an ordinary type.");

        // Create a Dictionary of Test objects, using strings for the
        // keys.       
        Dictionary<string, Test> d = new Dictionary<string, Test>();

        // Display information for the constructed type and its generic
        // type definition.
        DisplayGenericTypeInfo(d.GetType());
        DisplayGenericTypeInfo(d.GetType().GetGenericTypeDefinition());

        // Display information for an ordinary type.
        DisplayGenericTypeInfo(typeof(string));
    }
}

/* This example produces the following output:

--- Display information about a constructed type, its
    generic type definition, and an ordinary type.

System.Collections.Generic.Dictionary[System.String,Test]
        Is this a generic type definition? False
        Is it a generic type? True
        List type arguments (2):
                System.String
                Test

System.Collections.Generic.Dictionary[TKey,TValue]
        Is this a generic type definition? True
        Is it a generic type? True
        List type arguments (2):
                TKey    (unassigned - parameter position 0)
                TValue  (unassigned - parameter position 1)

System.String
        Is this a generic type definition? False
        Is it a generic type? False
 */
Imports System.Reflection
Imports System.Collections.Generic

Public Class Test
    Private Shared Sub DisplayGenericTypeInfo(ByVal t As Type) 
        Console.WriteLine(vbCrLf & t.ToString())
        
        Console.WriteLine(vbTab & "Is this a generic type definition? " _
            & t.IsGenericTypeDefinition)
        
        Console.WriteLine(vbTab & "Is it a generic type? " _
            & t.IsGenericType)
        
        If t.IsGenericType Then
            ' If this is a generic type, display the type arguments.
            '
            Dim typeArguments As Type() = t.GetGenericArguments()
            
            Console.WriteLine(vbTab & "List type arguments (" _
                & typeArguments.Length & "):")
            
            For Each tParam As Type In typeArguments
                ' If this is a type parameter, display its position.
                '
                If tParam.IsGenericParameter Then
                    Console.WriteLine(vbTab & vbTab & tParam.ToString() _
                        & vbTab & "(unassigned - parameter position " _
                        & tParam.GenericParameterPosition & ")")
                Else
                    Console.WriteLine(vbTab & vbTab & tParam.ToString())
                End If
            Next tParam
        End If
    
    End Sub 
    
    
    Public Shared Sub Main() 
        Console.WriteLine(vbCrLf & "--- Display information about a constructed type, its")
        Console.WriteLine("    generic type definition, and an ordinary type.")
        
        ' Create a Dictionary of Test objects, using strings for the
        ' keys.       
        Dim d As New Dictionary(Of String, Test)()

        DisplayGenericTypeInfo(d.GetType())
        DisplayGenericTypeInfo(d.GetType().GetGenericTypeDefinition())
        
        ' Display information for an ordinary type.
        DisplayGenericTypeInfo(GetType(String))
    
    End Sub
End Class

' This example produces the following output:
'
'--- Display information about a constructed type, its
'    generic type definition, and an ordinary type.
'
'System.Collections.Generic.Dictionary[System.String, Test]
'        Is this a generic type definition? False
'        Is it a generic type? True
'        List type arguments (2):
'                System.String
'                Test
'
'System.Collections.Generic.Dictionary[TKey,TValue]
'        Is this a generic type definition? True
'        Is it a generic type? True
'        List type arguments (2):
'                TKey    (unassigned - parameter position 0)
'                TValue  (unassigned - parameter position 1)
'
'System.String
'        Is this a generic type definition? False
'        Is it a generic type? False

Hinweise

Eine generische Typdefinition ist eine Vorlage, von der andere Typen erstellt werden können.A generic type definition is a template from which other types can be constructed. Beispielsweise aus der generischen Typdefinition G<T> (ausgedrückt in C# Syntax). G(Of Integer) MakeGenericType G<int> in Visual Basic oder generic <typename T> ref class G in C++) können Sie den-Typ (in Visual Basic) erstellen und instanziieren, indem Sie die-Methode mit einer generischen Argumentliste aufrufen, die das G(Of T) Int32geben Sie ein.For example, from the generic type definition G<T> (expressed in C# syntax; G(Of T) in Visual Basic or generic <typename T> ref class G in C++) you can construct and instantiate the type G<int> (G(Of Integer) in Visual Basic), by calling the MakeGenericType method with a generic argument list containing the Int32 type. Bei einem Type -Objekt, das diesen konstruierten GetGenericTypeDefinition Typ darstellt, ruft die-Methode die generische Typdefinition erneut ab.Given a Type object representing this constructed type, the GetGenericTypeDefinition method gets the generic type definition back again.

Verwenden Sie IsGenericTypeDefinition die-Eigenschaft, um zu bestimmen, ob Sie neue Typen aus dem aktuellen Typ erstellen können.Use the IsGenericTypeDefinition property to determine whether you can create new types from the current type. Wenn die IsGenericTypeDefinition -Eigenschaft truezurückgibt, kann die MakeGenericType -Methode aufgerufen werden, um neue generische Typen zu erstellen.If the IsGenericTypeDefinition property returns true, you can call the MakeGenericType method to create new generic types.

Eine Liste der invarianten Bedingungen für Begriffe, für Begriffe, die für die Reflektion mit generischen Methoden verwendet werden, finden Sie in den Hinweisen zur Eigenschaft IsGenericType.For a list of the invariant conditions for terms used in generic reflection, see the IsGenericType property remarks.

Gilt für:

Siehe auch