The framework calls this member function when the user presses the middle mouse button.
afx_msg void OnMButtonDown(
   UINT nFlags,
   CPoint point 
);
Parameters
- nFlags 
 Indicates whether various virtual keys are down. This parameter can be any combination of the following values:- MK_CONTROL Set if the CTRL key is down. 
- MK_LBUTTON Set if the left mouse button is down. 
- MK_MBUTTON Set if the middle mouse button is down. 
- MK_RBUTTON Set if the right mouse button is down. 
- MK_SHIFT Set if the SHIFT key is down. 
 
- point 
 Specifies the x- and y-coordinate of the cursor. These coordinates are always relative to the upper-left corner of the window.
Remarks
备注
This member function is called by the framework to allow your application to handle a Windows message. The parameters passed to your function reflect the parameters received by the framework when the message was received. If you call the base-class implementation of this function, that implementation will use the parameters originally passed with the message and not the parameters you supply to the function.
Requirements
Header: afxwin.h
See Also
Concepts
CWnd::OnMButtonDown