检测多个鼠标单击

Question

I have a problem with probably a simple solution, but I just dont get it right. So I want something to happen if I press the left mouse button.

private void DrawingPanel_MouseClick(object sender, MouseEventArgs e)
{  
  if (e.Button == MouseButtons.Left)
  {
   //something happens
  }
}

So, that works fine. but now the problem comes inn. Now I want to check for more clicks within the click event (now that I think about it, is that even possible?) Something like this:

private void DrawingPanel_MouseClick(object sender, MouseEventArgs e)
{  
  if (e.Button == MouseButtons.Left)
  {
   //something happens
   //blabla...
   if (e.Button == MouseButtons.Left)
   {
    //Do something
   }
  }
}

Is something like that possible? Because the second if (e.Button == MouseButtons.Left) is always true. How can I do it so that its not automaticlly true?

Answer 1

This won't work out the way you implemented it, because within that handler you still handle the one mouse-click event.

Try handling the Control.DoubleClick-event instead.

Answer 2

The MouseClick event is re-entered for every click (not taking into account double-clicks).
If you are trying to create logic for a multi-click procedure, a simple solution is maintaining a click counter on your class:

private int clickNo = 0;

private void DrawingPanel_MouseClick(object sender, MouseEventArgs e)
{  
   if (e.Button == MouseButtons.Left)
   {
       clickNo++;
       switch (clickNo)
       {
           case 1: Foo(); break;
           case 2: Bar(); break;
           case 3: Baz(); clickNo = 0; break;
       }
   }
}

Answer 3

You would actually end up with 2 click events because you have two clicks. If you are looking to emulate a double click functionality or something of the likes and the doubleclick event doesn't work for you, I would store the relevant data about the first click, along with a date time, out to some class scoped variables and compare to that datetime during the second click.

Answer 4

The following emulates a double click with a limited timespan to perform the two clicks in. This case it is 300 milliseconds. The DoubleClick event also works but only passes EventArgs instead of MouseEventArgs which severely limits its use.

    private int _clicks = 0;
    private void DoWhateverOnDoubleClick(object sender, MouseEventArgs e)
    {
        if(e.Button != MouseButtons.Left)return; // We want left clicks only
        if (++_clicks == 2) 
            DoWhatever(); // if double click then do whatever
        Task.Run(() =>
        {
            Thread.Sleep(300);
            _clicks = 0;
        }); // Reset clicks after 300 ms

    }