How to stop update value of slider while dragging it?

Question

I\'ve slider that its value is bind to some property, and the property updates it all the time. While dragging the [thumb on] slider I want to stop this update value of slider f

Answer 1

The template for Slider includes a Thumb, which raises the ThumbDragDelta event as the mouse is moved. Slider will always update the bound value immediately when it receives a ThumbDragDelta event.

The trick is to stop this event. The easiest way is to subclass Slider:

public class SliderIgnoreDelta : Slider
{
  protected override void OnThumbDragDelta(DragDeltaEventArgs e)
  {
    // Do nothing
  }
}

This slider will not update the value until the thumb drag completes.

Another solution is to intercept the ThumbDragDelta event on the Thumb. If you happen to be re-templating the Slider anyway, this might be a better solution. For example if you already have an EventBlocker class coded up that sets Handled true on the given RoutedEvent, you could put this in your template:

But for most cases you'll probably want to go with my first solution.