Retrieves the opacity and transparency color key of a layered window.
Pointer to a COLORREF value that receives the transparency color key to be used when composing the layered window. All pixels painted by the window in this color will be transparent. This can be NULL if the argument is not needed.
Pointer to a BYTE that receives the Alpha value used to describe the opacity of the layered window. When the variable referred to by pbAlpha is 0, the window is completely transparent. When the variable referred to by pbAlpha is 255, the window is opaque. This can be NULL if the argument is not needed.
Pointer to a DWORD that receives a layering flag. This can be NULL if the argument is not needed. For a complete list of possible values, see GetLayeredWindowAttributes.
This member function emulates the functionality of the function GetLayeredWindowAttributes, as described in the Platform SDK.