The WM_MOUSEHOVER message is posted to a window when the cursor hovers over the client area of the window for the period of time specified in a prior call to TrackMouseEvent.
A window receives this message through its WindowProc function.
Syntax
WM_MOUSEHOVER
WPARAM wParam
LPARAM lParam;
Parameters
- wParam
-
Indicates whether various virtual keys are down. This parameter can be one or more of the following values.
MK_CONTROL- The CTRL key is depressed.
MK_LBUTTON- The left mouse button is depressed.
MK_MBUTTON- The middle mouse button is depressed.
MK_RBUTTON- The right mouse button is depressed.
MK_SHIFT- The SHIFT key is depressed.
MK_XBUTTON1- Windows 2000/XP: The first X button is down.
MK_XBUTTON2- Windows 2000/XP: 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.
Return Value
If an application processes this message, it should return zero.
Remarks
Hover tracking stops when WM_MOUSEHOVER is generated. The application must call TrackMouseEvent again if it requires further tracking of mouse hover behavior.
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.
Notification Requirements
| Minimum DLL Version |
None |
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| Header | Declared in Winuser.h, include Windows.h |
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| Minimum operating systems |
Windows 98, Windows NT 4.0 |
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See Also