PRB: Releasing Object Variable Does Not Close Microsoft Excel

ID: Q132535

The information in this article applies to:

Microsoft Visual FoxPro for Windows, versions 3.0, 5.0, 5.0a, 6.0

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 of a change in behavior between Microsoft Excel 7.0 and Microsoft Excel 5.x. For more information, please see the following article in the Microsoft Knowledge Base.

Q147573 PRB: Microsoft Excel Not Registered in Running Object Table

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.

REFERENCES

For more information about the GETOBJECT function, please see the following article in the Microsoft Knowledge Base:

Q128994 Behavior of GETOBJECT() with Excel and Word for Windows

Additional query words: VFoxWin

Keywords : kbVFp300 kbVFp500 kbVFp600 FxinteropExcel
Version : WINDOWS: 3.0,5.0,5.0a,6.0
Platform : WINDOWS
Issue type :