Type.IsGenericTypeDefinition Type.IsGenericTypeDefinition Type.IsGenericTypeDefinition Type.IsGenericTypeDefinition Property

Определение

Возвращает значение, позволяющее определить, представляет ли текущий объект Type определение универсального типа, на основе которого можно сконструировать другие универсальные типы.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

Значение свойства

true Если Type объект представляет определение универсального типа; в противном случае false.if the Type object represents a generic type definition; otherwise, false.

Примеры

Следующий пример отображает сведения о типе, включая ли он определением универсального типа.The following example displays information about a type, including whether or not it is a generic type definition. Сведения отображаются для сконструированного типа, его определение универсального типа и обычный тип.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
Imports System.Reflection
Imports System.Collections.Generic
Imports Microsoft.VisualBasic

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 'Main
End Class 'Test

' 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

Комментарии

Определение универсального типа — это шаблон, из которого можно сконструировать другие типы.A generic type definition is a template from which other types can be constructed. Например, из определения универсального типа G<T> (выражена в синтаксис C#; G(Of T) в Visual Basic или generic <typename T> ref class G в C++) можно создавать и создает экземпляр типа G<int> (G(Of Integer) в Visual Basic), путем вызова MakeGenericType метод с универсальным аргументом список, содержащий Int32 типа.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. Учитывая Type объект, представляющий это сконструированный тип, GetGenericTypeDefinition метод получает определение универсального типа и обратно еще раз.Given a Type object representing this constructed type, the GetGenericTypeDefinition method gets the generic type definition back again.

Используйте IsGenericTypeDefinition свойства, чтобы определить, можно ли создавать новые типы из текущего типа.Use the IsGenericTypeDefinition property to determine whether you can create new types from the current type. Если IsGenericTypeDefinition возвращает true, можно вызвать MakeGenericType метод, чтобы создать новые универсальные типы.If the IsGenericTypeDefinition property returns true, you can call the MakeGenericType method to create new generic types.

Список неизменяемых условий для терминов, используемых в отражении универсальных типов, см. в примечаниях к описанию свойства IsGenericType.For a list of the invariant conditions for terms used in generic reflection, see the IsGenericType property remarks.

Применяется к

Дополнительно