BeginCancel

Question

Can I have a code sample on how to use BeginCancel 'public IAsyncResult BeginCancel(TimeSpan timeout, AsyncCallback callback, object state);'
and EndCancel 'EndCancel(IAsyncResult result);' , in order to cancel a workflow application.

Answer 1

@zeinab mokdad , you could use the following code to use BeginCancel and EndCancel to Cancel a workflow application.

The BeginCancel method is used to Cancel a workflow instance asynchronously using the specified time-out interval, AsyncCallback, and user-provided state.

The EndCancel method determines whether a BeginCancel operation was successful. If called before the cancel operation completes, it blocks until the cancel operation is complete.

Here is a code example you could refer to.

public partial class Form1 : Form  
    {  
        public Form1()  
        {  
            InitializeComponent();  
        }  
        WorkflowApplication wfApp;  
        private void Form1_Load(object sender, EventArgs ev)  
        {  
            Activity wf = new Sequence  
            {  
                Activities =  
     {  
         new WriteLine  
         {  
             Text = "Starting the workflow."  
         },  
         new Delay  
         {  
             Duration = TimeSpan.FromSeconds(20)  
         },  
         new WriteLine  
         {  
             Text = "Ending the workflow."  
         }  
     }  
            };  

            wfApp = new WorkflowApplication(wf);  

            // Subscribe to any desired workflow lifecycle events.  
            wfApp.Completed = delegate (WorkflowApplicationCompletedEventArgs e)  
            {  
                if (e.CompletionState == ActivityInstanceState.Faulted)  
                {  
                    Console.WriteLine("Workflow {0} Terminated.", e.InstanceId);  
                    Console.WriteLine("Exception: {0}\n{1}",  
                        e.TerminationException.GetType().FullName,  
                        e.TerminationException.Message);  
                }  
                else if (e.CompletionState == ActivityInstanceState.Canceled)  
                {  
                    Console.WriteLine("Workflow {0} Canceled.", e.InstanceId);  
                }  
                else  
                {  
                    Console.WriteLine("Workflow {0} Completed.", e.InstanceId);  

                    // Outputs can be retrieved from the Outputs dictionary,  
                    // keyed by argument name.  
                    // Console.WriteLine("The winner is {0}.", e.Outputs["Winner"]);  
                }  
            };  

            wfApp.Aborted = delegate (WorkflowApplicationAbortedEventArgs e)  
            {  
                // Display the exception that caused the workflow  
                // to abort.  
                Console.WriteLine("Workflow {0} Aborted.", e.InstanceId);  
                Console.WriteLine("Exception: {0}\n{1}",  
                    e.Reason.GetType().FullName,  
                    e.Reason.Message);  
            };  

            wfApp.Idle = delegate (WorkflowApplicationIdleEventArgs e)  
            {  
                // Perform any processing that should occur  
                // when a workflow goes idle. If the workflow can persist,  
                // both Idle and PersistableIdle are called in that order.  
                Console.WriteLine("Workflow {0} Idle.", e.InstanceId);  
            };  

            wfApp.PersistableIdle = delegate (WorkflowApplicationIdleEventArgs e)  
            {  
                // Instruct the runtime to persist and unload the workflow  
                return PersistableIdleAction.Unload;  
            };  

            wfApp.Unloaded = delegate (WorkflowApplicationEventArgs e)  
            {  
                Console.WriteLine("Workflow {0} Unloaded.", e.InstanceId);  
            };  

            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.  
                // Other choices are Abort and Cancel  
                return UnhandledExceptionAction.Terminate;  
            };  

        }  

        private void button1_Click(object sender, EventArgs e)  
        {  
            wfApp.Run();  
        }  
        void CallBack(IAsyncResult iar)  
        {  
            Console.WriteLine("call back");  
            wfApp.EndCancel(iar);  
        }  
        private void button2_Click(object sender, EventArgs e)  
        {  
            IAsyncResult result = wfApp.BeginCancel(new TimeSpan(10), CallBack, new object());  

        }  
    }  

Result:

---

If the response is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.