KB132535 - PRB: Releasing Object Variable Does Not Close Microsoft Excel

Article ID: 132535

Article Last Modified on 6/6/2003

Microsoft Visual FoxPro 3.0 Standard Edition
Microsoft Visual FoxPro 5.0 Standard Edition
Microsoft Visual FoxPro 5.0a
Microsoft Visual FoxPro 6.0 Professional Edition

This article was previously published under Q132535

SYMPTOMS

The CREATEOBJECT function can be used to create a reference to an instance of Microsoft Excel and assign that reference to a variable. However, releasing that variable does not cause the instance of Excel to quit.

Inadvertently creating multiple instances of Excel can cause a variety of error messages, depending on the machine configuration and Windows version. These error messages include:

"Insufficient Memory"
"Not enough memory"
"Page Fault"

RESOLUTION

If you are running Microsoft Excel 5.0, use the following code to close all instances of Microsoft Excel:

   PROCEDURE xlquit
   local llFlag
   ON ERROR  llFlag = .F. && Exit loop
   llFlag = .T.
   DO  WHILE  llFlag
      y=GETOBJECT (,"Excel.Application")
      y.QUIT
   ENDDO
   ON ERROR   && Set back to default

If you are using Microsoft Excel 7.0, use the following code:

   PROCEDURE xlquit
   DECLARE LONG FindWindowA IN USER32 AS FindA STRING,STRING
   DECLARE LONG SendMessageA IN USER32 AS SendA LONG, LONG, LONG, LONG
   WM_USER = 1024
   hwnd = FindA("XLMAIN", 0)
     DO  WHILE  hwnd > 0
       WhatD= SendA(hwnd, WM_USER + 18, 0, 0)
       y=GETOBJECT (,"Excel.Application")
       y.QUIT
       hwnd = FindA("XLMAIN", 0)
     ENDDO

The code is different because Microsoft Excel 95 contains a bug that was corrected in later versions.

If you are using Microsoft Office 2000 or Microsoft Office XP change the following code:

WhatD= SendA(hwnd, WM_USER + 18, 0, 0)

to the following:

WhatD= SendA(hwnd, WM_ACTIVATEAPP, 0, 0)

For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

153025 FIX: Microsoft Excel 95 Doesn't Respond Correctly toGetObject

NOTE: The DECLARE statements in the above example are case-sensitive and the functions must be called just as in the example.

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

Run the following code to create five instances of Microsoft Excel, none of which are visible:

   FOR i = 1 to 5
     x = CREATEOBJECT("Excel.Application")
     RELEASE x
   ENDFOR

Releasing the variable x does not terminate the instance of Microsoft Excel. To ensure that each instance is terminated, add the following command immediately before the RELEASE x command:

   x.Quit

To test if an instance of Microsoft Excel exists use this function:

   x=GETOBJECT(,"Excel.Application")  && The first argument is empty

This returns an OLE error if no instance of Microsoft Excel is in memory.

Additional query words: VFoxWin

Keywords: kbprb KB132535