how to implement both mouse down and click events for button ?

Question

I have a button which I want to Implement it's both event (mousedown and click)..

but I found interfere between Button_MouseDown and Button_Click, Actually I can't imagine why this happen ...

when I remove the mouse down event the click event handler work proberly ... but when I add mouse down event handler the debugger didn't even enter button_click method.

I attached the code cause I can't write and format here well.