How to get MouseDown after a few seconds? - wpf

Question

Assume I have a button and I want the following behavior:
when I click on the button, it fires up an event - ok, that's easy.
Now, if I click and wait, after a few seconds it suppose to fire up another event. e.g. popup a menu...
how to do that?

Answer 1

Are you checking the MouseUp event?
Is what you are saying if the user holds down the mouse button for 2 seconds to display a popup menu?
What I would do is on the MouseDown event create a separate thread waiting for the 2 seconds. If the MouseUp event is triggered before it expires then do nothing, else do the event.
// This event will be used for tracking if the MouseUp has been received
private System.Threading.AutoResetEvent _stopTrigger;
private void OnMouseDown(object sender, MouseButtonEventArgs e)
{
if (this._stopTrigger == null)
{
this._stopTrigger = new System.Threading.AutoResetEvent(false);
}
Action popupProcess = new Action(this.ShowPopupAfterTime);
// Make the Popup process on a separate thread
popupProcess.BeginInvoke(null, null);
}
private void OnMouseUp(object sender, MouseButtonEventArgs e)
{
if (this._stopTrigger != null)
{
// Sends the signal to the ShowPopupAfterTime that it should NOT display the pop up
// IIt will make WaitOne return true and not go into the if statement
this._stopTrigger.Set();
}
}
private void ShowPopupAfterTime()
{
// Will enter the if after 2 seconds
if (!this._stopTrigger.WaitOne(2000))
{
// This means it has NOT be trigged thus I can display the popup
// DISPLAY POPUP
// DON"T FORGET you are on a different thread here, NOT UI thread. You will have to use the Dispatcher to get back
// to the UI thread to display the popup
}
}

Answer 2

Look up Timer() and DispatcherTimer()

Answer 3

I would use threading like this
private void mousedownEvent(object sender, MouseButtonEventArgs e)
{
//Fire off a thread which will do the waiting in the background
new Thread(delegate()
{
//Wait for 2 seconds
Thread.Sleep(2000);
//dump a dowork() method onto the main thread
this.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Normal, new Action(delegate()
{
doWork(sender);
}));
return;
}).Start();
}
private void doWork(object sender)
{
//if the button is still pressed
if ((sender as UIElement).IsMouseOver && Mouse.LeftButton == MouseButtonState.Pressed)
{
//continue here
}
}
it will check a mouse button is pressed and then check again after 2 seconds without stalling the main app thread. I wou't check if the button was pressed the entire time so this may or may not be important to you
Shane

Answer 4

You can run timer for 2 seconds under MouseDown event and on timers tick event check what you need. Afer that you can stop your timer.

Answer 5

DispatcherTimer PopupTimer = new DispatcherTimer();
PopupTimer.Tick += new EventHandler(PopupTimerTick);
PopupTimer.Interval = new TimeSpan(0, 0, 0, 0,5);
private void PopupTimerTick(object sender, EventArgs e)
{
if (Mouse.LeftButton == MouseButtonState.Pressed)
{
// If still pressed showing popup
((Storyboard)Resources["ShowPopup"]).Begin();
PopupTimer.Stop();
}
}
private void ImageOnMouseDown(object sender, MouseButtonEventArgs e)
{
PopupTimer.Start();
e.Handled = true;
}
private void ImageOnMouseUp(object sender, MouseButtonEventArgs e)
{
e.Handled = true;
if (Popup.IsOpen == false)
{
((Storyboard)Resources["ShowPopup"]).Stop();
// Here the operation that works on the click
}
}