Type.GetGenericTypeDefinition Metod

public:
 abstract Type ^ GetGenericTypeDefinition();

public:
 virtual Type ^ GetGenericTypeDefinition();

public abstract Type GetGenericTypeDefinition();

public virtual Type GetGenericTypeDefinition();

abstract member GetGenericTypeDefinition : unit -> Type

abstract member GetGenericTypeDefinition : unit -> Type
override this.GetGenericTypeDefinition : unit -> Type

Public MustOverride Function GetGenericTypeDefinition () As Type

Public Overridable Function GetGenericTypeDefinition () As Type

Returer

Ett Type objekt som representerar en allmän typ som den aktuella typen kan konstrueras från.

Undantag

Exempel

I följande kodexempel skapas en instans av en konstruerad typ med hjälp av vanlig skapande av instanser och använder GetType sedan metoderna och GetGenericTypeDefinition för att hämta den konstruerade typen och den generiska typdefinitionen. I det här exemplet används den allmänna Dictionary<TKey,TValue> typen. Den konstruerade typen representerar ett Dictionary<TKey,TValue> objekt Test med strängnycklar.

using System;
using System.Reflection;
using System.Collections.Generic;

public class Test
{
    public static void Main()
    {
        Console.WriteLine("\r\n--- Get the generic type that defines a constructed type.");

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

        // Get a Type object representing the constructed type.
        //
        Type constructed = d.GetType();
        DisplayTypeInfo(constructed);

        Type generic = constructed.GetGenericTypeDefinition();
        DisplayTypeInfo(generic);
    }

    private static void DisplayTypeInfo(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);
        Type[] typeArguments = t.GetGenericArguments();
        Console.WriteLine("\tList type arguments ({0}):", typeArguments.Length);
        foreach (Type tParam in typeArguments)
        {
            Console.WriteLine("\t\t{0}", tParam);
        }
    }
}

/* This example produces the following output:

--- Get the generic type that defines a constructed type.

System.Collections.Generic.Dictionary`2[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`2[TKey,TValue]
        Is this a generic type definition? True
        Is it a generic type? True
        List type arguments (2):
                TKey
                TValue
 */

open System
open System.Collections.Generic

type Test() = class end

let displayTypeInfo (t: Type) =
    printfn $"\n{t}"
    printfn $"\tIs this a generic type definition? {t.IsGenericTypeDefinition}"
    printfn $"\tIs it a generic type? {t.IsGenericType}"
    let typeArguments = t.GetGenericArguments()
    printfn $"\tList type arguments ({typeArguments.Length}):"
    for tParam in typeArguments do
        printfn $"\t\t{tParam}"

printfn "\n--- Get the generic type that defines a constructed type."

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

// Get a Type object representing the constructed type.
let constructed = d.GetType()
displayTypeInfo constructed

let generic = constructed.GetGenericTypeDefinition()
displayTypeInfo generic


(* This example produces the following output:

--- Get the generic type that defines a constructed type.

System.Collections.Generic.Dictionary`2[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`2[TKey,TValue]
        Is this a generic type definition? True
        Is it a generic type? True
        List type arguments (2):
                TKey
                TValue
 *)

Imports System.Reflection
Imports System.Collections.Generic

Public Class Test
    Public Shared Sub Main() 
        Console.WriteLine(vbCrLf & "--- Get the generic type that defines a constructed type.")
        
        ' Create a Dictionary of Test objects, using strings for the
        ' keys.
        Dim d As New Dictionary(Of String, Test)
        
        ' Get a Type object representing the constructed type.
        '
        Dim constructed As Type = d.GetType()
        DisplayTypeInfo(constructed)
        
        Dim generic As Type = constructed.GetGenericTypeDefinition()
        DisplayTypeInfo(generic)
    End Sub
    
    Private Shared Sub DisplayTypeInfo(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)
        Dim typeArguments As Type() = t.GetGenericArguments()
        Console.WriteLine(vbTab & "List type arguments (" _
            & typeArguments.Length & "):")
        For Each tParam As Type In typeArguments
            Console.WriteLine(vbTab & vbTab & tParam.ToString())
        Next tParam
    End Sub
End Class

' This example produces the following output:
'
'--- Get the generic type that defines a constructed type.
'
'System.Collections.Generic.Dictionary`2[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`2[TKey,TValue]
'        Is this a generic type definition? True
'        Is it a generic type? True
'        List type arguments (2):
'                TKey
'                TValue
'

Kommentarer

En allmän typdefinition är en mall som andra typer kan konstrueras från. Från den allmänna C#-typdefinitionen G<T>kan du till exempel skapa och instansiera typen G<int>. Med tanke på ett Type objekt som representerar den här konstruerade typen GetGenericTypeDefinition returnerar metoden den generiska typdefinitionen.

Om två konstruerade typer skapas från samma generiska typdefinition, med samma typargument, GetGenericTypeDefinition returnerar metoden samma Type objekt för båda typerna.

Om du anropar metoden för GetGenericTypeDefinition ett Type objekt som redan representerar en allmän typdefinition returneras den aktuella Type.

En lista över de invarianta villkoren för termer som används i allmän reflektion finns i egenskapskommentarerna IsGenericType .

Se även

• MakeGenericType(Type[])
• ContainsGenericParameters
• IsGenericTypeDefinition
• Reflektion och generiska typer
• Så här gör du: Undersöka och instansiera generiska typer med reflektion