WPF: Button single click + double click issue

Hunsoul picture Hunsoul · Jun 9, 2009 · Viewed 30k times · Source

I have to handle both the single click and the double click of a button in a WPF application with different reaction. Unfortunately, on a doubleclick, WPF fires two click event and a double click event, so it's hard to handle this situation.

It tried to solve it using a timer but without success...I hope you can help me.

Lets see the code:

private void delayedBtnClick(object statInfo)
{
    if (doubleClickTimer != null)
        doubleClickTimer.Dispose();
    doubleClickTimer = null;

    this.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Normal, new VoidDelegate(delegate()
    {
        // ... DO THE SINGLE CLICK ACTION
    }));
}

private void btn_Click(object sender, RoutedEventArgs e)
{
    if (doubleClickTimer == null)
        doubleClickTimer = new Timer(delayedBtnClick, null, System.Windows.Forms.SystemInformation.DoubleClickTime, Timeout.Infinite);
        }
    }
}

private void btnNext_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
    if (doubleClickTimer != null)
        doubleClickTimer.Change(Timeout.Infinite, Timeout.Infinite);    // disable it - I've tried it with and without this line
        doubleClickTimer.Dispose();
    doubleClickTimer = null;

    //.... DO THE DOUBLE CLICK ACTION
}

The problem is that the 'SINGLE CLICK ACTION' called after the 'DOUBLE CLICK ACTION' on doubleclick. It's strange that I set thedoubleClickTimer to null on double click but in the delayedBtnClick it's true :O

I've already tried to use longer time, a bool flag and lock...

Do you have any ideas?

Best!

Answer

rmoore picture rmoore · Jun 9, 2009

If you set the RoutedEvent's e.Handled to true after handling the MouseDoubleClick event then it will not call the Click Event the second time after the MouseDoubleClick.

There's a recent post which touches on having different behaviors for SingleClick and DoubleClick which may be useful.

However, if you are sure you want separate behaviors and want/need to block the first Click as well as the second Click, you can use the DispatcherTimer like you were.

private static DispatcherTimer myClickWaitTimer = 
    new DispatcherTimer(
        new TimeSpan(0, 0, 0, 1), 
        DispatcherPriority.Background, 
        mouseWaitTimer_Tick, 
        Dispatcher.CurrentDispatcher);

private void Button_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
    // Stop the timer from ticking.
    myClickWaitTimer.Stop();

    Trace.WriteLine("Double Click");
    e.Handled = true;
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    myClickWaitTimer.Start();
}

private static void mouseWaitTimer_Tick(object sender, EventArgs e)
{
    myClickWaitTimer.Stop();

    // Handle Single Click Actions
    Trace.WriteLine("Single Click");
}