ComponentOne RibbonButton called by a background worker

Question

I am trying to change the SmallImage property of a C1 Ribbon Button when a background worker finishes.

The problem is I am getting "Cross-thread operation not valid: Control 'MyControl' accessed from a thread other than the thread it was created on."

I've worked around other Cross-threading problems by checking InvokeRequired on the Windows Control however the ComponenetOne control does not have an InvokeRequired property.

From researching I thought accessing the Controls image property in the progresschanged event would work around the problem. Below is the relevant code. Both the doWork and progresschanged event are run on the Worker thread however so I' still getting the Cross-Threading problem. Can anyone see what I maybe am doing wrong or is there another way I can solve the problem?

    private void InitializeBackgroundWorker1()
    {
        BackgroundWorker1 = new BackgroundWorker();
        BackgroundWorker1.DoWork +=
            new DoWorkEventHandler(BackgroundWorker1_DoWork);

        BackgroundWorker1.RunWorkerCompleted +=
            new RunWorkerCompletedEventHandler(BackgroundWorker1_RunWorkerCompleted);

        BackgroundWorker1.ProgressChanged +=
            new ProgressChangedEventHandler(BackgroundWorker1_ProgressChanged);

        BackgroundWorker1.WorkerReportsProgress = true;
    }

    private void BackgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
    {
        e.Result = sResult;
        (sender as BackgroundWorker).ReportProgress(25);
    }

    private void BackgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e) 
    {            
        MyControl1.ribbonButtonStatus.SmallImage = Properties.Resources.trafficlight_green;            
    }


    private void ThisAddIn_Startup(object sender, System.EventArgs e)
    {
        MyControl1 = new TimeGridControl();
    ...
}

Have you tried checking the `InvokeRequired` property of the control's container (maybe the Form)? — ScottieMc, Jul 10 '12 at 17:58
I have tried that with no luck, am thinking of ways around this as no one else can seem to help. But thanks ScottieMc for replying. — Anthony White, Aug 01 '12 at 12:01

score 0 · Answer 1 · answered Dec 15 '14 at 20:59

You didnt post the code from where you're starting your backgroundworker, but if your progresschanged event is marshalling to a worker thread. It means you're starting the working from an other thread then the main thread. The background worker captures the SynchronizationContext from where it's started to marshall the calls in the progresschanged and runworkercompleted event.

ComponentOne RibbonButton called by a background worker

1 Answers1