WM_MBUTTONUP message (Windows)

Applies to: desktop apps only

Posted when the user releases the middle mouse 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.

A window receives this message through its WindowProc function.

#define WM_MBUTTONUP                    0x0208

Parameters

wParam

Indicates whether various virtual keys are down. This parameter can be one or more of the following values.

Value	Meaning
MK_CONTROL 0x0008	The CTRL key is down.
MK_LBUTTON 0x0001	The left mouse button is down.
MK_MBUTTON 0x0010	The middle mouse button is down.
MK_RBUTTON 0x0002	The right mouse button is down.
MK_SHIFT 0x0004	The SHIFT key is down.
MK_XBUTTON1 0x0020	The first X button is down.
MK_XBUTTON2 0x0040	The second X button is down.

 

lParam

The low-order word specifies the x-coordinate of the cursor. The coordinate is relative to the upper-left corner of the client area.

The high-order word specifies the y-coordinate of the cursor. The coordinate is relative to the upper-left corner of the client area.

Note that when a shortcut menu is present (displayed), coordinates are relative to the screen, not the client area. Because TrackPopupMenu is an asynchronous call and the WM_MBUTTONUP notification does not have a special flag indicating coordinate derivation, an application cannot tell if the x,y coordinates contained in lParam are relative to the screen or the client area.

Return value

If an application processes this message, it should return zero.

Remarks

Use the following code to obtain the horizontal and vertical position:

xPos = GET_X_LPARAM(lParam); 
yPos = GET_Y_LPARAM(lParam); 

You can also use the MAKEPOINTS macro to convert the lParam parameter to a POINTS structure.

Requirements

See also

Reference

GET_X_LPARAM

GET_Y_LPARAM

GetCapture

SetCapture

WM_MBUTTONDBLCLK

WM_MBUTTONDOWN

Conceptual

Mouse Input

Other Resources

MAKEPOINTS

POINTS

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Build date: 3/6/2012