WM_NCMBUTTONDBLCLK
The
WM_NCMBUTTONDBLCLK message is posted when the user double-clicks the middle
mouse button while the cursor is within the nonclient area of a window. This
message is posted to the window that contains the cursor. If a window has
captured the mouse, this message is not posted.
WM_NCMBUTTONDBLCLK
nHittest = (INT) wParam; // hit-test value
pts = MAKEPOINTS(lParam); // position of cursor
Parameters
nHittest
Value of wParam.
Specifies the hit-test value returned by the DefWindowProc function as a result of
processing the WM_NCHITTEST message. For a list of hit-test values, see WM_NCHITTEST.
pts
Value of lParam.
Specifies a POINTS
structure that contains the x- and y-coordinates of the cursor. The coordinates
are relative to the upper-left corner of the screen.
Return Values
If an
application processes this message, it should return zero.
Remarks
A window need
not have the CS_DBLCLKS style to receive WM_NCMBUTTONDBLCLK messages.
Windows
generates a WM_NCMBUTTONDBLCLK message when the user presses, releases, and
again presses the middle mouse button within the system s double-click time
limit. Double-clicking the middle mouse button actually generates four
messages: WM_NCMBUTTONDOWN, WM_NCMBUTTONUP, WM_NCMBUTTONDBLCLK, and
WM_NCMBUTTONUP again.
An
application can use the MAKEPOINTS macro to convert the lParam
parameter to a POINTS structure.
If it is
appropriate to do so, the system sends the WM_SYSCOMMAND message to the window.
See Also