Wait for a while without blocking main thread

Question

I wish my method to wait about 500 ms and then check if some flag has changed. How to complete this without blocking the rest of my application?

Answer 1

I've recently been struggling with the same issue where I needed an action to be run on schedule without blocking the UI.

Here's my solution:

private void Button_Click(object sender, RoutedEventArgs e)
{
    RunOnSchedule(interval, cancellationToken);
}

private void RunOnSchedule(int interval, CancellationToken cancellationToken)
{
    // Start the task you want to run on schedule
    TaskToRunOnSchedule(args);
    Task.Run(async () => 
    {
        // This loop checks if the task was requested to be cancelled every 1000 ms
        for (int x = 0; x < interval; x+=1000)
        {
            if (cancellationToken.IsCancellationRequested)
            {
                break;
            }

            await Task.Delay(1000);
        }
    }).GetAwaiter().OnCompleted(() =>
    {
        // Once the task for delaying is completed, check once more if cancellation is requested, as you will reach this point regardless of if it was cancelled or not.
        if (!cancellationToken.IsCancellationRequested)
        {
            // Run this method again
            RunOnSchedule(interval, cancellationToken);
        }
    });
}