System 2.0.0.0 4.0.0.0 System.Attribute System.AttributeUsage(System.AttributeTargets.Parameter) The attribute allows you to specify a default parameter value in a language that does not otherwise support default parameters. After you apply this attribute to your code, languages that support default parameters can use the specified value as a default parameter. Note that the does not add support for default parameters to languages that do not support this feature. For example, if you use the with a method written in C#, which does not support default parameters, you cannot use the default parameter when calling the method from C#. You can use the default parameter only when calling the method in a language such as C++ that does support the feature. The is particularly useful to specify default parameters for methods of a COM interop interface. Sets the default value of a parameter when called from a language that supports default parameters. This class cannot be inherited. Constructor 2.0.0.0 4.0.0.0 Use this constructor to apply the attribute to a parameter written in a language such as Microsoft Visual C# that does not support default parameters. Initializes a new instance of the class with the default value of a parameter. An object that represents the default value of a parameter. Property 2.0.0.0 4.0.0.0 System.Object To be added. To be added. Gets the default value of a parameter.