WorkflowApplicationUnhandledExceptionEventArgs Class

.NET Framework (current version)

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Provides information about an unhandled exception that occurred in a workflow instance.

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


public class WorkflowApplicationUnhandledExceptionEventArgs : WorkflowApplicationEventArgs


Gets the activity that is the source of the unhandled exception.


Gets the unique identifier of the activity instance that is the source of the unhandled exception.


The unique identifier of the workflow instance.(Inherited from WorkflowApplicationEventArgs.)


Gets the Exception that was unhandled by the workflow instance.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Gets the collection of extensions of the specified type.(Inherited from WorkflowApplicationEventArgs.)


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


Creates a shallow copy of the current Object.(Inherited from Object.)


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

If an exception is thrown by an activity and is unhandled, the default behavior is to terminate the workflow instance. If an OnUnhandledException handler is present, it can override this default behavior. This handler gives the workflow host author an opportunity to provide the appropriate handling, such as custom logging, aborting the workflow, canceling the workflow, or terminating the workflow.

The following example invokes a workflow that throws an exception. The exception is unhandled by the workflow and the OnUnhandledException handler is invoked. The WorkflowApplicationUnhandledExceptionEventArgs are inspected to provide information about the exception, and the workflow is terminated.

Activity wf = new Sequence
    Activities =
         new WriteLine
             Text = "Starting the workflow."
         new Throw
            Exception = new InArgument<Exception>((env) => 
                new ApplicationException("Something unexpected happened."))
        new WriteLine
             Text = "Ending the workflow."

WorkflowApplication wfApp = new WorkflowApplication(wf);

wfApp.OnUnhandledException = delegate(WorkflowApplicationUnhandledExceptionEventArgs e)
    // Display the unhandled exception.
    Console.WriteLine("OnUnhandledException in Workflow {0}\n{1}",
        e.InstanceId, e.UnhandledException.Message);

    Console.WriteLine("ExceptionSource: {0} - {1}",
        e.ExceptionSource.DisplayName, e.ExceptionSourceInstanceId);

    // Instruct the runtime to terminate the workflow.
    return UnhandledExceptionAction.Terminate;

    // Other choices are UnhandledExceptionAction.Abort and 
    // UnhandledExceptionAction.Cancel


.NET Framework
Available since 4.0

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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