TopClose.exe Closes Child Forms of Top-Level Forms

• Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a, 6.0

SUMMARY

One of the sample project files for this article provides an example of a way to close a Top-Level form and have the user prompted to close each child form. Another sample project file shows a way to try to do this that does not work. Still another sample project file shows a way to accomplish the task that almost works or will work in limited circumstances. The following files are available for download from the Microsoft Download Center. Click the file names below to download the files:

Topclose.exe

http://www.microsoft.com/downloads/search.asp

MORE INFORMATION

In Visual FoxPro 5.0, forms can be set to show as Top-Level forms. Other child forms can be opened in the Top-Level form. This article will discuss a way to close the Top-Level form and have the user prompted for saving changes to any child forms contained in the Top-Level form. The solution presented will work the best in Visual FoxPro 5.0a and only partially in Visual FoxPro 5.0 or later due to changes in how the QueryUnload method is called.

Note that the solution presented here is not necessarily the only way to handle this situation. More sophisticated schemes can be developed. In fact, this article does not consider the case of Windows being exited with the application running.

Also note that the scenario presented here is fairly complex. Microsoft Product Support Engineers will not know all the issues presented in this article without spending some time working with the sample files. Please remember this if asking questions on the enclosed files.

Additional Information

• Almost.app



• Almost.pjx



• Almost.pjt - These are the application file and the project files from which it was made.



• Almost.scx



• Almost.sct - The form files for the main Top-Level form.



• Almost.mnx



• Almost.mnt - The menu that is placed in the Top-Level form, Almost.scx.



• Almost.prg - The main program in the project.



• AlmostBlue.scx



• AlmostBlue.sct



• AlmostGreen.scx



• AlmostGreen.sct



• AlmostRed.scx



• AlmostRed.sct - The form files for the child forms of the Top-Level form.

• Bad.app



• Bad.pjx



• Bad.pjt - These are the application file and the project files from which it was made.



• Bad1.scx



• Bad1.sct - The form files for the main Top-Level form.



• Bad1.mnx



• Bad1.mnt - The menu that is placed in the Top-Level form, Bad1.scx.



• Bad1.prg - The main program in the project.



• BadBlue.scx



• BadBlue.sct



• BadGreen.scx



• BadGreen.sct



• BadRed.scx



• BadRed.sct - The form files for the child forms of the Top-Level form.

• Good.app



• Good.pjx



• Good.pjt - These are the application file and the project files from which it was made.



• Good1.scx



• Good1.sct - The form files for the main Top-Level form.



• Good1.mnx



• Good1.mnt - The menu that is placed in the Top-Level form, Good1.scx.



• Good1.prg - The main program in the project.



• GoodBlue.scx



• GoodBlue.sct



• GoodGreen.scx



• GoodGreen.sct



• GoodRed.scx



• GoodRed.sct - The form files for the child forms of the Top-Level form.

1. Set the Visual FoxPro working folder to either TopClose\Bad TopClose\Almost or TopClose\Good. Use the File Locations tab of the Tools menu, Options dialog box or use the SET DEFAULT TO command in the Command window. For example, if the TopClose folder is on the C:\ drive:




SET DEFAULT TO c:\TopClose\Bad 

2. If the default folder is set to TopClose\Bad, DO Bad.app. If the default folder is set to TopClose\Good, DO Good.app or Almost.app if the default is TopClose\Almost.



3. The forms in each application can be run as many times as desired. For instance, two or three copies of the GoodRed form can be run. When a form is run more than once, it will come up in the same place so be sure to move a form after running it once if it is going to be run again. Otherwise, it won't be obvious that it is there more than once.



4. If the process of running the Almost application, rebuilding it and running it again is repeated a few times, this may cause Visual FoxPro to unexpectedly quit. This is currently under investigation. The application termination seems to always happen during the building of the application and should not effect the running application. Another problem that may occur is that a "phantom" copy of the Top-Level form may also be noticed on the Windows Taskbar for each time the application is run in the development environment. Although this appears as a problem in the Visual FoxPro development environment, no problems have been observed if the project is built into an executable file and it is run as a stand-alone executable and the Top-Level form is the main form in the executable's interface. If the Top-Level form is only one part of an executable, the method of closing the child forms illustrated in Good.app should be used. The executable also has problems if run under the development environment. That is why this version of the application is named "almost." It almost works.

Q175682 PRB: VFP Crashes When Working With Top-Level and Child Forms

Discussion Of Sample Files' Behavior

*** QueryUnload of Good Top-Level form

   LOCAL lAllClosed, lFormOpen
   lAllClosed=.T.
   lFormOpen=.F.
   LOCAL xx
   xx=_Screen.FormCount

   * The CloseBox or Close command in the application menu was chosen
   IF This.ReleaseType=1
      IF MESSAGEBOX(;
         "Are you ready to close this top-level form?",36,;
         "QueryUnload of "+THIS.Caption) = 7
         NODEFAULT
         lAllClosed=.F.
         RETURN lAllClosed
      ENDIF
   ENDIF

   * The Quit menu option was chosen
   IF This.ReleaseType=0 AND xx>1

      IF MESSAGEBOX(;
         "Are you ready to close this top-level form?",36,;
         "QueryUnload of "+THIS.Caption) = 7
         NODEFAULT
         lAllClosed=.F.
         RETURN lAllClosed
      ENDIF
   ENDIF

   * Attempt to close all active forms via each form's QueryUnload event
      DO WHILE TYPE('_SCREEN.ACTIVEFORM') = "O" AND ;
                  _SCREEN.ACTIVEFORM.NAME <> "_"
            IF NOT _SCREEN.ACTIVEFORM.QUERYUNLOAD()
                  lAllClosed = .F.
                  NODEFAULT
                  EXIT
            ENDIF
         ENDDO
   RETURN lAllClosed
   *** End of QueryUnload of Good Top-Level form **********************

   *** QueryUnload of a Child form - either the GoodRed or GoodGreen.scx

   LOCAL x,xx,ans,cTopLevelCaption
   * Getting the caption of the Top-Level form to use in dialog boxes
   xx = _SCREEN.FormCount
   FOR x = 1 TO xx
      IF _SCREEN.FORMS[x].NAME = "_"
         cTopLevelCaption = _SCREEN.FORMS[x].Caption
         EXIT
      ENDIF
   ENDFOR
   ******

   * Optionally save changes before closing the form
   ans = MESSAGEBOX(;

         "Do you want to save changes to the "+CHR(13)+;
         THIS.Caption+"?",35,cTopLevelCaption)
   DO CASE
      CASE ans = 6   && Yes
         WAIT WINDOW "Changes saved" TIMEOUT 1
      CASE ans = 7   && No
         WAIT WINDOW "Changes NOT saved" TIMEOUT 1
      CASE ans = 2   && Cancel
         * Abort closing this form
         NODEFAULT
         * Return to calling program
         RETURN .F.
   ENDCASE
   THIS.RELEASE && if QueryUnload called as a method 

REFERENCES

Visual FoxPro Help; search on ShowWindow property and QueryUnload method.

© Microsoft Corporation 1999, All Rights Reserved.
Contributions by John W. Spilker, Microsoft Corporation

Additional query words:

Keywords : kbcode kbfile kbsample kbOOP kbVFp500 kbGrpFox
Version : WINDOWS:5.0,5.0a,6.0
Platform : WINDOWS
Issue type : kbinfo