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ServiceHostBase.UnknownMessageReceived Event


Occurs when an unknown message is received.

 event EventHandler<System::ServiceModel::UnknownMessageReceivedEventArgs ^> ^ UnknownMessageReceived;
public event EventHandler<System.ServiceModel.UnknownMessageReceivedEventArgs> UnknownMessageReceived;
member this.UnknownMessageReceived : EventHandler<System.ServiceModel.UnknownMessageReceivedEventArgs> 
Public Custom Event UnknownMessageReceived As EventHandler(Of UnknownMessageReceivedEventArgs) 
Public Event UnknownMessageReceived As EventHandler(Of UnknownMessageReceivedEventArgs) 

Event Type



When using WorkflowServiceHost, exposing a hosting endpoint, and a UnknownMessageReceived exception is thrown, the host passes the message to the event handler. If an attempt is made to read this message an InvalidOperationException is thrown. The description of the exception will say "This message cannot support the operation because it has been read." The WCF infrastructure reads the message while extracting the message parameters. This message is then passed to the event handler and any attempt to read it causes an exception. If you need to access message parameters in your InvalidOperationException handler from a hosting endpoint, define the hosting endpoint contract using MessageContract and place the needed data into a message header. For more information about hosting endpoints, see Workflow Service Host Extensibility

Applies to