Delegate.CombineImpl Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Concatenates the invocation lists of the specified delegate and the current delegate.

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


Protected Overridable Function CombineImpl ( _
    d As Delegate _
) As Delegate
protected virtual Delegate CombineImpl(
    Delegate d


  • d
    Type: System.Delegate
    The delegate whose invocation list is to be combined with the invocation list of the current delegate.

Return Value

Type: System.Delegate
A new delegate with an invocation list that concatenates the invocation list of the current delegate and the invocation list of d, or the current delegate if d is nulla null reference (Nothing in Visual Basic).


Exception Condition

In all cases.


Application code attempts to access this member late-bound, for example, by using the Type.InvokeMember method.


The current implementation throws a MulticastNotSupportedException in all cases. This does not matter because all delegate types in the common language runtime (CLR) are derived from MulticastDelegate, and therefore they are combined by using the MulticastDelegate.CombineImpl method, which overrides this protected base class method. You cannot derive a delegate type directly from Delegate, so this protected method is never called.

Version Information


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0


For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.