WM_MBUTTONDOWN

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Windows Embedded CE 6.0 R3

4/8/2010

This message is posted when the user presses the middle mouse button while the cursor is located within the client area of a window. If another window has not captured the mouse, the OS posts the message to the window beneath the cursor. If another window has captured the mouse, the OS posts the message to the window that has captured the mouse.

A window receives this message through the WindowProc function for the window.

Syntax

WM_MBUTTONDOWN 
    fwKeys = wParam; 
    xPos = LOWORD(lParam); 
    yPos = HIWORD(lParam);

Parameters

• fwKeys
  Indicates the mouse buttons and keys that the user pressed. The following table shows the possible values, which can be combined.

  Value	Description
  MK_CONTROL	The user pressed the CTRL key.
  MK_LBUTTON	The user pressed the left mouse button.
  MK_MBUTTON	The user pressed the middle mouse button.
  MK_RBUTTON	The user pressed the right mouse button.
  MK_SHIFT	The user pressed the SHIFT key.

• xPos
  Value of the low-order word of lParam. Specifies the x-coordinate of the pointer, relative to the upper-left corner of the client area.

• yPos
  Value of the high-order word of lParam. Specifies the y-coordinate of the pointer, relative to the upper-left corner of the client area.

Return Value

An application that processes this message should return zero.

Requirements

See Also

Reference

GetAsyncKeyState
GetCapture
GetKeyState
SetCapture
WindowProc
WM_MBUTTONUP