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4/8/2010

This message is posted when the user presses the touch screen in the client area of a window or presses the left mouse button while the cursor is located within the client area of a window. If another window does not capture the mouse or stylus event, the OS posts the message to the window beneath the stylus or mouse. If another window does capture the mouse or stylus, the OS posts the message to the window that has the capture.

Syntax 

WM_LBUTTONDOWN 
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_LBUTTONUP

The left mouse button is up.

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 cursor, 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 cursor, relative to the upper-left corner of the client area.

Return Value

An application should return zero if it processes this message.

Requirements

Header windows.h
Windows Embedded CE Windows CE 1.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also