Use clickcount = 2 and prevent from entering into left click event in c# wpf

Question

I have to execute some code at left click of mouse and I have to perform separate actions on double click but my Canvas doesn't support doubleclick event, so, I am trying to get the work done by clickcount but it also, enters left click event before coming to clickcount = 2 . How do I prevent this? I know I have to use e.handled = true but i can't understand where. Any help would be appreciated.

void Canvas_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
    if(e.ClickCount == 2)
    {
     // Some code
    }
    else
    {
        if(e.ChangedButton == MouseButton.Left)
        {
            // some code
        }
    }
}

Possible duplicate of [How can I catch both single-click and double-click events on WPF FrameworkElement?](https://stackoverflow.com/questions/2086213/how-can-i-catch-both-single-click-and-double-click-events-on-wpf-frameworkelemen) — IDarkCoder, Jul 09 '19 at 06:06

score 0 · Accepted Answer · edited Jul 09 '19 at 06:19

0

Like @IDarkCoder said, this seems to have already been answered on a different question. The back code should be similar to this:

private Timer _delayTimer;

public Constructor()
{
...
  _delayTimer = new Timer(300);
  _delayTimer.Elapsed += DelayTimer_Elapsed;
}

private void Canvas_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
  if (e.ChangedButton == MouseButton.Left && e.ClickCount == 1)
  {
    _delayTimer.Start();
  }
  else if (e.ClickCount == 2)
  {
    e.Handled = true;
    _delayTimer.Stop();
  }
  else
  {
     _delayTimer.Stop();
  }
}

private void DelayTimer_Elapsed(object sender, ElapsedEventArgs e)
{
 // Do your thing here for Single Left Click.
}

And also make sure that your Canvas has a Background set in the UI, even if it is a Transparent one, or else you will not be able to catch the mouse events.

edited Jul 09 '19 at 06:19

IDarkCoder

709
7
18

answered Jul 09 '19 at 06:15

Lupu Silviu

1,145
11
23

And my code for double click should be before stopping the timer or after that? – Aarushi Bhatia Jul 09 '19 at 06:24
Where I put the 'e.Handled=true', inside the PreviewMouseDown event, after Stop(); – Lupu Silviu Jul 09 '19 at 06:26
My single click code was using mousebuttoneventargs, how do I access it now? – Aarushi Bhatia Jul 09 '19 at 06:38
You can store the 'MouseButtonEventArgs e' in a private Member 'private MouseButtonEventArgs _lastEventArgs', and set it where you start the timer. '_lastEventArgs=e'. What are you using it for? – Lupu Silviu Jul 09 '19 at 06:40
To get the position of mouse pointer on Canvas. It throws an exception. Says it requires another thread. – Aarushi Bhatia Jul 09 '19 at 06:47
The use a 'private Point _lastClickPosition;' instead, and set it where you start the timer with the value you want to use later. – Lupu Silviu Jul 09 '19 at 06:48
How do I get back to my UI thread because, later in the flow of the program, it throws the same exception. – Aarushi Bhatia Jul 09 '19 at 06:53
Dispatcher.Invoke(()=>{ ... your code ...}); This works if you want the code to be executed when you make the call, You can use the BeginInvoke method also, which is async. – Lupu Silviu Jul 09 '19 at 06:56

Use clickcount = 2 and prevent from entering into left click event in c# wpf

1 Answers1