WideStudio/MWT Programming Guide	WideStudio/MWT Index Table of contents

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How to indicate a dialog on the WSEV_EXIT event procedure

It is necessary to save data to indicate a dialog, when you finish the application by closing the window. In such a case, it is convenient to use the WSEV_EXIT event procedure of the WSCwindow/WSCmainWindow class.

The WSCwindow/WSCmainWindow class generates the WSEV_EXIT trigger when the window is disappeared before finishing the application.

At first set True to the property WSNexit of a WSCwindow/WSCmainWindow instance which is used as main window in the application, and put an event procedure to it with WSEV_EXIT trigger.

We will try to make an event procedure to have the following facility.

Indicates the dialog whether exit or continue.

If [OK] is selected,execute some procedure and exit the application.

If [NO] is selected,exit the application with no process.

If [CANCEL] is selected, do nothing and do not exit the application.

#include <WScom.h>
#include <WSCfunctionList.h>
#include <WSCbase.h>
//----------------------------------------------------------
//Function for the event procedure
//----------------------------------------------------------
#include <WSCmessageDialog.h>
#include <WSDtimer.h>

//The timer procedure which redisplay the window.
void delayproc(unsigned char,void* ptr){
  WSCbase* object = (WSCbase*)ptr;
  object->setVisible(True);
}
//EXIT event procedure
//Indicates a dialog.
void exit_ep(WSCbase* object){
  if (object->getVisible() != False){
    return;
  }
  WSCmessageDialog* msg = WSGIappMessageDialog(); //A
  msg->setProperty(WSNwidth,500);
  msg->setProperty(WSNno,True);
  msg->setProperty(WSNdefaultPosition,True);
  msg->setProperty(WSNlabelString,
  "Exit and save data?\n If you do not want to save and exit,push NO...");
  //Indicates the dialog.
  long ret = msg->popup(); //B

  if (ret == WS_DIALOG_OK){ //When OK is selected.. C
    //saving some data ...
    exit(0);
  }else
  if (ret == WS_DIALOG_NO){ //When NO is selected.. D
    exit(0);
  }else
  if (ret == WS_DIALOG_CANCEL){ //When CANCEL is selected.. E
    WSGIappTimer()->addTriggerProc(delayproc,WS250MS,object);
  }
}
static WSCfunctionRegister  op("exit_ep",(void*)exit_ep);

Get the instance of the message dialog (A),indicate it (B). Check the result of the dialog (C)(D)(E). It is necessary to execute delayed procedure to redisplay the window. Exit event is required before the window is redisplayed.

[The exit dialog]