Microsoft KB Archive/167528

= FIX: Class Browser Causes System Error on Exit =

Article ID: 167528

Article Last Modified on 12/6/2000

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APPLIES TO


 * Microsoft Visual FoxPro 5.0 Standard Edition, when used with:
 * Microsoft Windows 95
 * Microsoft Visual FoxPro 5.0a, when used with:
 * Microsoft Windows 95

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This article was previously published under Q167528



SYMPTOMS
If either of the TreeView ActiveX controls in the Class Browser have focus when you press Escape to close the Class Browser, a General Protection Fault (GPF) or Invalid Page Fault occurs. This problem occurs only under Windows 95; it does not occur under Windows NT.



CAUSE
This occurs when a new version of Comctl32.ocx has been installed. This problem occurs with any version of this file dated 1/16/97 or later.

The problem actually occurs in any form using the ActiveX controls from this .ocx file if the form is released before the code associated with the ActiveX control is completed.



RESOLUTION
Follow these steps to implement an add-in for the Class Browser to fix the problem described above:

  Create a program named Brwescfx.prg in the root Visual FoxPro directory with the following code: * Program...........: Brwescfx.prg * Author............: Ken R. Levy * Copyright.........: None (Public Domain) * Description.......: VFP 5.0 Class Browser patch for 1-16-97 *                     COMCTL32.OCX bug. * Note:  This add-in patch only fixes GPFs that occur when pressing * ESC to exit. *     *  Instructions for installation: * 1. Save Brwescfx.prg program file above into your VFP home/root *    directory. * 2. Launch the Class Browser in VFP 5.0 and open any VCX. * 3. Run Barwescfx.prg to automatically register the BrwESCFx Class *    Browser add-in. * 4. No more GPFs will occur using the Class Browser when pressing *    ESC. *

LPARAMETERS oSource

IF TYPE("oSource")#"O" OR ISNULL(oSource) IF TYPE("_oBrowser")#"O" OR ISNULL(_oBrowser) MESSAGEBOX("You must have the Class Browser running " + ;                 "to register BrwESCFx.", 48,"BrwESCFx") RETURN .F.         ENDIF IF _oBrowser.AddIn("BrwESCFx",HOME+"BrwESCFx","QueryUnload") MESSAGEBOX("BrwESCFx has successfully been " + ;                 "registered.",0,"BrwESCFx") RETURN ENDIF MESSAGEBOX("BrwESCFx failed to be registered.",16,"BrwESCFx") RETURN .F.     ENDIF IF NOT oSource.cAddInMethod=="QUERYUNLOAD" RETURN .F.     ENDIF IF TYPE("_screen.ActiveForm.ActiveControl")#"O" OR ; LOWER(LEFT(_screen.ActiveForm.ActiveControl.Name,3))=="ole" oSource.lNoDefault=.T.         oSource.cboClassType.SetFocus KEYBOARD "{ESC}" PLAIN ENDIF RETURN * END PROGRAM: BrwESCFx.PRG  Launch the Class Browser in Visual FoxPro and open any VCX. Run Brwescfx.prg (created in Step 1) to automatically register the BrwESCFx Class Browser add-in.



STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This has been corrected in Visual FoxPro 6.0.



Steps to Reproduce Behavior

 * 1) Launch the Class Browser and open any VCX.
 * 2) Click in one of the TreeView controls to ensure it has focus.
 * 3) Press Escape to exit the Class Browser.

If the version of Comctl32.ocx indicated in the "Cause" section above is installed, the error should occur.

Keywords: kbbug kbfix kbvfp600fix kbprb kbcode KB167528

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