We recommend using Visual Studio 2017
This documentation is archived and is not being maintained.


The framework calls this member function when the user presses XBUTTON1 or XBUTTON2 while the cursor is in the client area of a window.

afx_msg void OnXButtonDown(
    UINT nFlags, 
    UINT nButton, 
    CPoint point



[in] nFlags

A bitwise combination (OR) of flags that indicate which modifier keys are pressed. For example, the MK_CONTROL flag indicates that the CTRL key is pressed.

[in] nButton

A value of XBUTTON1 if the first Microsoft Intellimouse X button was clicked, or XBUTTON2 if the second X button was clicked.

[in] point

A CPoint object that specifies the x and y coordinates of the cursor relative to the upper-left corner of the client area.

This method receives the WM_XBUTTONDOWN notification, which is described in the Windows SDK. 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.

The nFlags parameter can be a combination of modifier keys listed in the following table. For more information, see About Mouse Input.

Modifier Key



The CTRL key is pressed.


The left mouse button is pressed.


The middle mouse button is pressed.


The right mouse button is pressed.


The SHIFT key is pressed.


The XBUTTON1 mouse button of the Microsoft IntelliMouse is pressed.


The XBUTTON2 mouse button of the Microsoft IntelliMouse is pressed.


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.

Header: afxwin.h

This method is supported in Windows Vista and later.

Additional requirements for this method are described in Build Requirements for Windows Vista Common Controls.