Type.GetGenericTypeDefinition Method

'Declaration
Public Overridable Function GetGenericTypeDefinition As Type
'Usage
Dim instance As Type
Dim returnValue As Type

returnValue = instance.GetGenericTypeDefinition

public Type GetGenericTypeDefinition ()

public function GetGenericTypeDefinition () : Type

Imports System
Imports System.Reflection
Imports System.Collections.Generic
Imports Microsoft.VisualBasic


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 'Main
    
    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 'DisplayTypeInfo
End Class 'Test

' 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
' 

import System.*;
import System.Reflection.*;
import System.Collections.Generic.*;

public class Test
{
    public static void main(String[] args)
    {
        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);
    } //main

    private static void DisplayTypeInfo(Type t)
    {
        Console.WriteLine("\r\n{0}", t);
        Console.WriteLine("\tIs this a generic type definition? {0}",
            (System.Boolean)t.get_IsGenericTypeDefinition());
        Console.WriteLine("\tIs it a generic type? {0}",
            (System.Boolean)t.get_IsGenericType());
        Type typeArguments[] = t.GetGenericArguments();
        Console.WriteLine("\tList type arguments ({0}):",
            (Int32)typeArguments.get_Length());
        for (int iCtr = 0; iCtr < typeArguments.get_Length(); iCtr++) {
            Type tParam = (Type)typeArguments.get_Item(iCtr);
            Console.WriteLine("\t\t{0}", tParam);
        }
    } //DisplayTypeInfo
} //Test

/* 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
 */