DefaultParameterValueAttribute Class
 

Sets the default value of a parameter when called from a language that supports default parameters. This class cannot be inherited.

Namespace:   System.Runtime.InteropServices
Assembly:  System (in System.dll)

SystemObject
   SystemAttribute
    System.Runtime.InteropServicesDefaultParameterValueAttribute

[AttributeUsageAttribute(AttributeTargets.Parameter)]
public sealed class DefaultParameterValueAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Parameter)]
public ref class DefaultParameterValueAttribute sealed : Attribute
[<Sealed>]
[<AttributeUsageAttribute(AttributeTargets.Parameter)>]
type DefaultParameterValueAttribute = 
    class
        inherit Attribute
    end
<AttributeUsageAttribute(AttributeTargets.Parameter)>
Public NotInheritable Class DefaultParameterValueAttribute
	Inherits Attribute
NameDescription
System_CAPS_pubmethod DefaultParameterValueAttribute

Initializes a new instance of the DefaultParameterValueAttribute class with the default value of a parameter.

NameDescription
System_CAPS_pubproperty

When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)

System_CAPS_pubproperty

Gets the default value of a parameter.

NameDescription
System_CAPS_pubmethod Equals

This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)

System_CAPS_pubmethod GetHashCode

Returns the hash code for this instance.(Inherited from Attribute.)

System_CAPS_pubmethod GetType

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethod IsDefaultAttribute

When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)

System_CAPS_pubmethod Match

When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)

System_CAPS_pubmethod ToString

Returns a string that represents the current object.(Inherited from Object.)

NameDescription
System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetIDsOfNames

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfo

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfoCount

Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeInvoke

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

The DefaultParameterValueAttribute 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 DefaultParameterValueAttribute does not add support for default parameters to languages that do not support this feature. For example, if you use the DefaultParameterValueAttribute 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 DefaultParameterValueAttribute is particularly useful to specify default parameters for methods of a COM interop interface.

The following code example demonstrates how to apply the DefaultParameterValueAttribute attribute to a parameter of a method written in C#.

static public void MethodWithDefaultParam([System.Runtime.InteropServices.DefaultParameterValue("DEFAULT_PARAM_VALUE")] string var)
{
	Console.WriteLine("The passed value is: " + var);
}
Universal Windows Platform
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone
Available since 8.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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