The framework calls this member when the current window is composed by the Desktop Window Manager (DWM), and that window is maximized.
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.
For a list of flags, see the "Message Parameters" subheading in About Mouse Input.
Indicates the distance the wheel is rotated, expressed in multiples or divisions of WHEEL_DELTA, which is 120. A positive value indicates that the wheel was rotated to the right; a negative value indicates that the wheel was rotated to the left.
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_MOUSEHWHEEL notification message, which is described in the Windows SDK. This message is sent to the window that has the focus when the mouse's horizontal scroll wheel is tilted or rotated.
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.
This method is supported in Windows Vista and later.
Additional requirements for this method are described in Build Requirements for Windows Vista Common Controls.