How To Produce a List of Other Applications Running in Windows

MORE INFORMATION

It is sometimes necessary for a FoxPro application to determine whether another application is running. The following article explains how to use the FindWindow() function to determine whether a particular application is running: In order to use the FindWindow() function, you need to know the complete text of the window title. In some cases, the complete text of the window title cannot be known. When a document is opened in Microsoft Word, for example, the title of the Microsoft Word window will contain the text "Microsoft Word - " followed by the name of the document that is being edited. Since it is not possible for a FoxPro application to know the full text of the window title in cases like this, the FindWindow() function cannot be used to determine whether the application is running.

To work around this situation, this article provides a code sample that uses the Windows API GetWindowText() function to produce a list of all visible windows currently running in Microsoft Windows, with the exception of Microsoft FoxPro.

The IsWindEx() function can be used in two ways. This function can be used to determine whether there is a visible window that contains the specified string of text. This function can also be used to produce a list of all visible windows currently in existence.

To determine whether there is a visible window that contains a specified string of text, call the function with the text that you are interested in checking. For example, to determine whether there are any windows that contain the text "Microsoft Word", call the function as follows:

   ? IsWindEx("Microsoft Word")
				

To produce a list of all visible windows currently in existence, call the function with a null value, as follows:

   =IsWindEx("")
				

Code Sample

FUNCTION IsWindEx
PARAMETERS WindowName

     IsWindEx = .F.

     SET LIBRARY TO foxtools.fll

     * Register the Windows API functions that will be called

     mGetWinTxt = RegFn("GetWindowText", "I@CI", "I")
     mGetWindow = RegFn("GetWindow", "II", "I")
     mIsWinVis =  RegFn("IsWindowVisible", "I", "I")

     * Get the HWND (handle) to the main FoxPro window

     foxhwnd = MAINHWND()

     * Produce a list of all windows

        hwndNext = CallFn(mGetWindow,foxhwnd,0)

     DO WHILE hwndNext <> 0

          IF (hwndnext <> foxhwnd) .AND. ;
               CallFn(mGetWindow,hwndnext,4) = 0 .AND. ;
               CallFn(mIsWinVis,hwndnext) <> 0

               Stuffer = SPACE(64)
               x = CallFn(mGetWinTxt,hwndnext,@Stuffer,64)

               * If a window name was specified, check to
               * see if this is the specified window. If a
               * window name was not specified, display the
               * name of the window.

               IF LEN(TRIM(WindowName)) = 0

                    ? Stuffer

               ELSE

                    IF WindowName $ Stuffer

                         IsWindEx = .T.
                         EXIT

                    ENDIF

               ENDIF

          ENDIF

         hwndNext = CallFn(mGetWindow,hwndnext,2)

        ENDDO

     SET LIBRARY TO

     IF LEN(TRIM(WindowName)) = 0

          IsWindEx = .T.

     ENDIF

RETURN IsWindEx

For more information about the functions called in this code sample, please refer to the documentation for the Windows 3.1 Software Development Kit or the Microsoft Developer's Network (MSDN) Development Library CD-ROM.

For more information about the algorithm used in this article, please refer to the following article in the Microsoft Knowledge Base: