This message is sent to the first window in the clipboard-viewer chain when the contents of the clipboard change. Only applications that have joined the clipboard-viewer chain by calling the SetClipboardViewer function need to process this message.
| Parameter | Description |
| wParam | Is not used. | |
| lParam | Is not used. |
Each window that receives the WM_DRAWCLIPBOARD message should call the SendMessage function to pass the message on to the next window in the clipboard-viewer chain. The handle of the next window is returned by the SetClipboardViewer function; it may be modified in response to a WM_CHANGECBCHAIN message.