Visual C++ and MFC Programming 2nd Edition

Visual C++ and MFC Fundamentals Chapter 5: The Document/View Architecture

3. Return to MSVC

4.5.3 The Mouse-Up Messages...................................................................

After pressing a mouse button, the user usually releases it. While the button is being

released, a button-up message is sent and it depends on the button, left or right, that was

down.

If the left mouse is being released, the ON_WM_LBUTTONUP message is sent. Its

syntax is:

afx_msg void OnLButtonUp(UINT nFlags, CPoint point);

If the right mouse is being released, the ON_WM_TBUTTONUP message is sent. Its

syntax is:

afx_msg void OnRButtonUp(UINT nFlags, CPoint point);

The first argument, nFlags, specifies what button, right or middle, is down or what

keyboard key and what mouse button were down. It is a constant integer that can have

one of the following values:

Value Description

MK_CONTROL A Ctrl key was held down

MK_MBUTTON The middle mouse button was down

MK_RBUTTON The right mouse button was down

MK_SHIFT A Shift key was held

The point argument specifies the measure from the (0, 0) origin of the window to the

mouse pointer.

Practical Learning: Sending a Mouse Down Message

1. To experiment with a mouse up message, change the program as follows:

#include <afxwin.h>