Type.GetGenericArguments Method (System)

GetGenericArguments Method

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Microsoft Visual Studio 2008/.NET Framework 3.5

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.NET Framework Class Library

Type..::.GetGenericArguments Method

Updated: November 2007

Returns an array of Type objects that represent the type arguments of a generic type or the type parameters of a generic type definition.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

Syntax

Visual Basic (Declaration)

Public Overridable Function GetGenericArguments As Type()

Visual Basic (Usage)

Dim instance As Type
Dim returnValue As Type()

returnValue = instance.GetGenericArguments()

public virtual Type[] GetGenericArguments()

Visual C++

public:
virtual array<Type^>^ GetGenericArguments()

public Type[] GetGenericArguments()

JScript

public function GetGenericArguments() : Type[]

Return Value

Type: array<System..::.Type>[]()[]

An array of Type objects that represent the type arguments of a generic type. Returns an empty array if the current type is not a generic type.

Remarks

The array elements are returned in the order in which they appear in the list of type arguments for the generic type.

If the current type is a closed constructed type (that is, the ContainsGenericParameters property returns false), the array returned by the GetGenericArguments method contains the types that have been assigned to the generic type parameters of the generic type definition.
If the current type is a generic type definition, the array contains the type parameters.
If the current type is an open constructed type (that is, the ContainsGenericParameters property returns true) in which specific types have not been assigned to all of the type parameters and type parameters of enclosing generic types or methods, the array contains both types and type parameters. Use the IsGenericParameter property to tell them apart. For a demonstration of this scenario, see the code example for the ContainsGenericParameters property.

For a list of the invariant conditions for terms used in generic reflection, see the IsGenericType property remarks.

Examples

The following code example uses the GetGenericArguments method to display the type arguments of a constructed type and the type parameters of its generic type definition.

This code example is part of a larger example provided for the IsGenericTypeDefinition property.

Visual Basic

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

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);
        }
    }
}

Visual C++

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 );
      }
   }
}

if (t.get_IsGenericType()) {
    // If this is a generic type, display the type arguments.
    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 = typeArguments[iCtr];
        // If this is a type parameter, display its
        // position.

        if (tParam.get_IsGenericParameter()) {
            Console.WriteLine("\t\t{0}\t(unassigned - parameter "
                + "position {1})", tParam, 
                (Int32)tParam.get_GenericParameterPosition());
        }
        else {
            Console.WriteLine("\t\t{0}", tParam);
        }
    }
}

Platforms

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information