CODEWITHSUNDEEP
c#wpfcancel-button
wjhguitarman
wjhguitarman

Reputation: 1073

Cancel Button Functionality in C# and XAML

I am trying to hash out the functionality of a cancel button for a WPF App. Currently there are 2 functions I am focusing on:

    private void AnalysisClick(object sender, RoutedEventArgs e)
    {
        model.RunAnalysis();
    }
    private void CancelClick(object sender, RoutedEventArgs e)
    {

        model.RunAnalysis().Abort;  //Pseudo-code, needs help!
        MessageBox.Show("The Analysis was cancelled.", "Operation Cancelled", MessageBoxButton.YesNo);
    }

The ' AnalysisClick ' function is started with a button called Begin. The goal of the ' CancelClick ' button is to stop the Analysis and to provide a dialog box informing the user that the test was stopped. What is the best way to achieve this?

EDIT I am currently looking into BackgroundWorker and Microsoft Asynchronous Programming Model per Users' suggestions.

Upvotes: 4

Views: 1961

Answers (1)

denis morozov
denis morozov

Reputation: 6316

I agree with the comments above to your question, but if you want to try something quickly Tasks are a great way to do async operation with ability to cancel those tasks. Something like this should work or at least get you started:

private CancellationTokenSource _cancelAnalysisTask = new CancellationTokenSource();
    private Task _analysisTask;

    private void AnalysisClick(object sender, RoutedEventArgs e)
    {
        _analysisTask = Task.Factory.StartNew(() =>
            {
                if (_cancelAnalysisTask.IsCancellationRequested)
                        return;
                model.RunAnalysis();
            });
    }

    private void CancelClick(object sender, RoutedEventArgs e)
    {
        if (_analysisTask != null)
        {
            _cancelAnalysisTask.Cancel();
            _analysisTask = null;
            MessageBox.Show("The Analysis was cancelled.", "Operation Cancelled", MessageBoxButton.OK);
        }
    }

This is a quick write-up, what I would recommend is putting async functionality into your ViewModel and expose Commands. UI shouldn't really know the details of operations. Then Cancelling the Task can be written near/before the meat of the operation within the ViewModel, where it makes more sense to abort the expensive operation/loop/etc.

Upvotes: 2

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