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Type.GetGenericArguments Method

  • Reference

Definition

Namespace:
System
Assembly:
System.Runtime.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll
Source:
Type.cs
Source:
Type.cs
Source:
Type.cs

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

public:
 virtual cli::array <Type ^> ^ GetGenericArguments();
public virtual Type[] GetGenericArguments ();
abstract member GetGenericArguments : unit -> Type[]
override this.GetGenericArguments : unit -> Type[]
Public Overridable Function GetGenericArguments () As Type()

Returns

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.

Exceptions

NotSupportedException

The invoked method is not supported in the base class. Derived classes must provide an implementation.

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. See the larger example for sample output.

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.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);
        }
    }
}

if t.IsGenericType then
    // If this is a generic type, display the type arguments.
    let typeArguments = t.GetGenericArguments()

    printfn $"\tList type arguments ({typeArguments.Length}):"

    for tParam in typeArguments do
        // If this is a type parameter, display its
        // position.
        if tParam.IsGenericParameter then
            printfn $"\t\t{tParam}\t(unassigned - parameter position {tParam.GenericParameterPosition})"
        else
            printfn $"\t\t{tParam}"

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

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.

Applies to

See also