CComControlBase::m_bUsingWindowRgn
Flag indicating the control is using the container-supplied window region.
unsigned m_bUsingWindowRgn:1;
Remarks
Note
To use this data member within your control class, you must declare it as a data member in your control class. Your control class will not inherit this data member from the base class because it is declared within a union in the base class.
Requirements
Header: atlctl.h