Adds this window to the chain of windows that are notified (by means of the WM_DRAWCLIPBOARD message) whenever the content of the Clipboard is changed.
HWND SetClipboardViewer( );
A handle to the next window in the Clipboard-viewer chain if successful. Applications should save this handle (it can be stored as a member variable) and use it when responding to Clipboard-viewer chain messages.
This member function sends a WM_DRAWCLIPBOARD message to the window. Since the handle to the next window in the Clipboard-viewer chain has not yet been returned, the application should not pass on the WM_DRAWCLIPBOARD message that it receives during the call to SetClipboardViewer.
To remove itself from the Clipboard-viewer chain, an application must call the ChangeClipboardChain member function.