#661 – ButtonBase.Click Event vs. Mouse Click Events

Controls that derive from ButtonBase, like the standard Button, inherit a Click event that fires when user clicks on the button using the left mouse button.

Because ButtonBase inherits from UIElement, a Button will also have access to all of the mouse button events defined for UIElement.

Because the Button does something in response to button presses, it swallows the bubbling events (e.g. MouseLeftButtonDown and MouseDown).  You can still detect these lower level button press events by adding handlers for the tunneling events (e.g. PreviewMouseLeftButtonDown and PreviewMouseDown).  You can also request that your handlers are called even for already-handled events by specifying a handler in code and setting the handledEventsToo parameter to true.

For a left-click on a Button, you’ll normally see click-related events in the following order:

• UIElement.PreviewMouseLeftButtonDown 
• UIElement.PreviewMouseDown
• UIElement.PreviewMouseLeftButtonUp
• UIElement.PreviewMouseUp
• ButtonBase.Click