重新启动BackgroundWorker C＃和WPF

Question

I read this guide about the BackgroundWorker class.

I am trying to implement a reset button, so I added following code.

In Page.xaml :

<Button x:Name="buttonReset" Content="Reset" Click="buttonReset_Click"
                    Width="80" Height="30"/>

and in Page.cs :

    private void buttonReset_Click(object sender, RoutedEventArgs e)
    {
        if (bw.WorkerSupportsCancellation == true)
        {
            bw.CancelAsync();
        }

        // How to restart?

        bw.RunWorkerAsync(); // Raises busy exception

    }

But I get following error:

From italian:

This BackgroundWorker is busy and couldn't execute more than one task in the same time

This exactly occurs only when I press Start a Reset .

Why? And how to fix?

Answer 1

Please note that this is a bad solution even if works

I tried this:

    private void buttonReset_Click(object sender, RoutedEventArgs e)
    {
        if (bw.WorkerSupportsCancellation == true)
        {
            bw.CancelAsync();

            while (bw.IsBusy)
            {
                DoEvents();
            }
        }

        bw.RunWorkerAsync();

    }

    public static void DoEvents()
    {
        Application.Current.Dispatcher.Invoke(DispatcherPriority.Background,
                                              new Action(delegate { }));
    }

This solved the problem.

In particular i added:

     while (bw.IsBusy)
     {
          DoEvents();
     }

where DoEvents() is defined:

    public static void DoEvents()
    {
        Application.Current.Dispatcher.Invoke(DispatcherPriority.Background,
                                              new Action(delegate { }));
    }

as mentioned ( here ).

Note: special thanks to a mysterious user who replied here but deleted his answer.