查delphi的帮助,或msdn都有详细介绍<br>如WM_CLOSE<br>The WM_CLOSE message is sent as a signal that a window or an<br> application should terminate. <br><br>WM_CLOSE <br> <br><br>Parameters<br><br>This message has no parameters. <br><br>Return Values<br><br>If an application processes this message, it should return zero. <br><br>Default Action<br><br>The DefWindowProc function calls the DestroyWindow function <br>to destroy the window. <br><br>Remarks<br><br>An application can prompt the user for confirmation,<br> prior to destroying a window, by processing the WM_CLOSE message and <br>calling the DestroyWindow function only if the user confirms the choice. <br>