#692 – Common Controls Typically Do Not Capture the Mouse

It’s a convention within Windows that controls typically do not capture the mouse after they intercept a mouse down event.  For example, you click on a Button by pressing and releasing the left mouse button.  But if you press the left mouse button, and then move the mouse pointer off the button before releasing, the mouse will not get clicked.

Avoiding a mouse capture in this case allows the user to avoid a click action after inadvertently pressing the left mouse button down over the wrong user interface element.