REFERENCE GUIDE

DefMDIChiidProcReturn valueCommentswParamIParamWORD Specifies 16 bits of additional message-dependentinforma tion.DWORD Specifies 32 bits of additional messagedependentinformation.The return value specifies the result of the message processing anddepends on the actual message sent.This function assumes that the parent of the window identified by theh Wnd parameter was created with the MDICLIENT class.Normally, when an application's window procedure does not handle amessage, it passes the message to the DefWindowProc function, whichprocesses the message. MDI applications use the DefFrameProc andDefMDIChiidProc functions instead of DefWindowProc to provide defaultmessage processing. All messages that an application would normallypass to DefWindowProc (such as non client messages and WM_SETTEXT)should be passed to DefMDIChiidProc instead. In addition to these,DefMDIChiidProc also handles the following messages:MessageWM_CHILDACTIVATEWM_GETMINMAXINFOWM_MENUCHARWM_MOVEWM_SETFOCUSWM_SIZEWM_SYSCOMMANDDefault Processing by DefMDlChiidProcPerforms activation processing when child windowsare sized, moved, or shown. This message must bepassed.Calculates the size of a maximized MDI childwindow based on the current size of the MDI clientwindow.Sends the key to the frame window.Recalculates MDI client scroll bars, if they arepresent.Activates the child window if it is not the activeMDI child.Performs necessary operations when changing thesize of a window, especially when maximizing orrestoring an MDI child window. Failing to pass thismessage to DefMDIChiidProc will produce highlyundesirable results.Also handles the "next window" command.DefWindowProcSyntaxLONGDefWindowProdh Wnd, wMsg, wParam, lParam)function DefWindowProc(Wnd: HWnd; Msg, wParam: Word; lParam:Longint): Longint;226 Software development kit