WM_CHANGECBCHAIN

This message notifies the first window in the clipboard-viewer chain that a window is being removed from the chain.

Parameter Description  

wParam Contains the handle to the window that is being removed from the clipboard-viewer chain.  
lParam Contains in its low-order word the handle to the window that follows the window being removed from the clipboard-viewer chain.  

Comments

Each window that receives the WM_CHANGECBCHAIN message should call the SendMessage function to pass on the message to the next window in the clipboard-viewer chain. If the window being removed is the next window in the chain, the window specified by the low-order word of the lParam parameter becomes the next window, and clipboard messages are passed on to it.