WM_XBUTTONDOWN top-level constant

int const WM_XBUTTONDOWN

Posted when the user presses the first or second X button while the cursor is in the client area of a window. If the mouse is not captured, the message is posted to the window beneath the cursor. Otherwise, the message is posted to the window that has captured the mouse.

Implementation

const WM_XBUTTONDOWN = 0x020B;