नोट
इस पेज तक पहुँच के लिए प्रमाणन की आवश्यकता होती है. आप साइन इन करने या निर्देशिकाओं को बदलने का प्रयास कर सकते हैं.
इस पेज तक पहुँच के लिए प्रमाणन की आवश्यकता होती है. आप निर्देशिकाओं को बदलने का प्रयास कर सकते हैं.
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.
#define WM_MOUSEHOVER 0x02A1
Parameters
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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 depressed. - MK_LBUTTON
- 0x0001
The left mouse button is depressed. - MK_MBUTTON
- 0x0010
The middle mouse button is depressed. - MK_RBUTTON
- 0x0002
The right mouse button is depressed. - MK_SHIFT
- 0x0004
The SHIFT key is depressed. - MK_XBUTTON1
- 0x0020
The XBUTTON1 is down. - MK_XBUTTON2
- 0x0040
The XBUTTON2 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);
As noted above, the x-coordinate is in the low-order short of the return value; the y-coordinate is in the high-order short (both represent signed values because they can take negative values on systems with multiple monitors). If the return value is assigned to a variable, you can use the MAKEPOINTS macro to obtain a POINTS structure from the return value. You can also use the GET_X_LPARAM or GET_Y_LPARAM macro to extract the x- or y-coordinate.
Important
Do not use the LOWORD or HIWORD macros to extract the x- and y- coordinates of the cursor position because these macros return incorrect results on systems with multiple monitors. Systems with multiple monitors can have negative x- and y- coordinates, and LOWORD and HIWORD treat the coordinates as unsigned quantities.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows 2000 Professional [desktop apps only] |
| Minimum supported server |
Windows 2000 Server [desktop apps only] |
| Header |
|
See also
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Reference
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Conceptual
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Other Resources