WM_MBUTTONDBLCLK message
Posted when the user double-clicks the middle mouse button while the cursor is in the client area of a window. If the mouse is not captured, the message is posted to the window beneath the cursor. Otherwise, the message is posted to the window that has captured the mouse.
A window receives this message through its WindowProc function.
#define WM_MBUTTONDBLCLK 0x0209
Parameters
- wParam
-
Indicates whether various virtual keys are down. This parameter can be one or more of the following values.
- 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
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.
Only windows that have the CS_DBLCLKS style can receive WM_MBUTTONDBLCLK messages, which the system generates 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_MBUTTONDOWN, WM_MBUTTONUP, WM_MBUTTONDBLCLK, and WM_MBUTTONUP again.
Requirements
|
Minimum supported client |
Windows 2000 Professional [desktop apps only] |
|---|---|
|
Minimum supported server |
Windows 2000 Server [desktop apps only] |
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Header |
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See also
- Reference
- GET_X_LPARAM
- GET_Y_LPARAM
- GetCapture
- GetDoubleClickTime
- SetCapture
- SetDoubleClickTime
- WM_MBUTTONDOWN
- WM_MBUTTONUP
- Conceptual
- Mouse Input
- Other Resources
- MAKEPOINTS
- POINTS