The framework calls this method when it fills the background of an auto-hide button.
virtual void OnFillBackground(
   CDC* pDC,
   CRect rect 
);
Parameters
- [in] pDC 
 A pointer to a device context.
- [in] rect 
 The bounding rectangle of the auto-hide button.
Remarks
If you want to customize the background for auto-hide buttons in your application, create a new class derived from the CMFCAutoHideButton Class. In your derived class, override this method.
Requirements
Header: afxautohidebutton.h