MethodInfo.GetGenericArguments Method

Definition

Namespace:

System.Reflection

Assembly:

System.Runtime.dll

Source:

MethodInfo.cs

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

public:
 override cli::array <Type ^> ^ GetGenericArguments();

public override Type[] GetGenericArguments ();

override this.GetGenericArguments : unit -> Type[]

Public Overrides Function GetGenericArguments () As Type()

Returns

Type[]

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

Exceptions

NotSupportedException

This method is not supported.

Examples

The following code example shows how to get the type arguments of a generic method and display them.

This example is part of a larger example provided for the MakeGenericMethod method.

// If this is a generic method, display its type arguments.
//
if (mi->IsGenericMethod)
{
    array<Type^>^ typeArguments = mi->GetGenericArguments();

    Console::WriteLine("\tList type arguments ({0}):", 
        typeArguments->Length);

    for each (Type^ tParam in typeArguments)
    {
        // IsGenericParameter is true only for generic type
        // parameters.
        //
        if (tParam->IsGenericParameter)
        {
            Console::WriteLine("\t\t{0}  parameter position {1}" +
                "\n\t\t   declaring method: {2}",
                tParam,
                tParam->GenericParameterPosition,
                tParam->DeclaringMethod);
        }
        else
        {
            Console::WriteLine("\t\t{0}", tParam);
        }
    }
}

// If this is a generic method, display its type arguments.
//
if (mi.IsGenericMethod)
{
    Type[] typeArguments = mi.GetGenericArguments();

    Console.WriteLine("\tList type arguments ({0}):",
        typeArguments.Length);

    foreach (Type tParam in typeArguments)
    {
        // IsGenericParameter is true only for generic type
        // parameters.
        //
        if (tParam.IsGenericParameter)
        {
            Console.WriteLine("\t\t{0}  parameter position {1}" +
                "\n\t\t   declaring method: {2}",
                tParam,
                tParam.GenericParameterPosition,
                tParam.DeclaringMethod);
        }
        else
        {
            Console.WriteLine("\t\t{0}", tParam);
        }
    }
}

' If this is a generic method, display its type arguments.
'
If mi.IsGenericMethod Then
    Dim typeArguments As Type() = mi.GetGenericArguments()
    
    Console.WriteLine(vbTab & "List type arguments ({0}):", _
        typeArguments.Length)
    
    For Each tParam As Type In typeArguments
        ' IsGenericParameter is true only for generic type
        ' parameters.
        '
        If tParam.IsGenericParameter Then
            Console.WriteLine(vbTab & vbTab _
                & "{0}  parameter position: {1}" _
                & vbCrLf & vbTab & vbTab _
                & "   declaring method: {2}", _
                tParam,  _
                tParam.GenericParameterPosition, _
                tParam.DeclaringMethod)
        Else
            Console.WriteLine(vbTab & vbTab & tParam.ToString())
        End If
    Next tParam
End If

Remarks

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

• If the current method is a closed constructed method (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 method definition.

• If the current method is a generic method definition, the array contains the type parameters.

• If the current method is an open constructed method (that is, the ContainsGenericParameters property returns true) in which specific types have been assigned to some type parameters and type parameters of enclosing generic types have been assigned to other type parameters, 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 specific to generic methods, see the IsGenericMethod property. For a list of the invariant conditions for other terms used in generic reflection, see the Type.IsGenericType property.

See also

• IsGenericMethod
• IsGenericMethodDefinition
• GetGenericMethodDefinition()
• IsGenericType
• Reflection and Generic Types
• Introduction to Generics (C# Programming Guide)