BUG: Fatal Error When You Close Forms That Use DHTML Edit Control (266363)


The information in this article applies to:

  • Microsoft Visual FoxPro for Windows 6.0
This article was previously published under Q266363

SYMPTOMS

When you release a form being executed that contains a Dynamic HTML Edit Control (DHTMLed.ocx), a fatal exception error may occur.

CAUSE

The fatal exception error occurs when the _VFP.AutoYield property is set to False (.F.). The fatal exception error may occur on Microsoft Windows 2000, regardless of the setting of the _VFP.AutoYield property.

RESOLUTION

When you execute forms that contain the Dynamic HTML Edit Control, set the _VFP.AutoYield property to True (.T.).

NOTE: Setting the _VFP.AutoYield property to True (.T.) does not prevent the occurrence of a fatal exception on Windows 2000.

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

NOTE: The Microsoft Dynamic HTML Edit Control has not been tested with and may not be supported by Microsoft Visual FoxPro.

This behavior does not occur when forms containing the Dynamic HTML Edit Control are released on Microsoft Windows NT 4.0.

This behavior occurs when Microsoft Visual FoxPro forms that contain the Dynamic HTML Edit Control are released on the Microsoft Windows 2000 Server, regardless of the value of _VFP.AutoYield.

The Visual FoxPro Help Documentation indicates that the AutoYield property should be set to False (.F.) when a form contains an ActiveX control. Setting AutoYield to False (.F.) prevents events for an ActiveX control from executing between lines of user program code.

Steps to Reproduce Behavior

  1. Create a program file named Dhtml.prg, by using the following code:
    PUBLIC ox
OldAutoYield=_VFP.AutoYield
_VFP.AutoYield=.T.
FOR i=1 TO 10
   ox=CREATEOBJECT("DEMO")
   ox.SHOW
   IF _VFP.AUTOYIELD
      WAIT WINDOW "AutoYield = TRUE" NOWA
   ELSE
      WAIT WINDOW "AutoYield = FALSE" NOWA
   ENDIF
   FOR EACH oform IN _SCREEN.FORMS
      oform.RELEASE
   ENDFOR
   IF i=5
      _VFP.AUTOYIELD=.F.
   ENDIF
ENDFOR
*!* Reset the AutoYield property to default
_VFP.AUTOYIELD=OldAutoYield

DEFINE CLASS demo AS FORM
   TOP = 0
   LEFT = 0
   AUTOCENTER = .T.
   HEIGHT = 454
   WIDTH = 633
   DOCREATE = .T.
   CAPTION = "Form1"
   NAME = "Form1"

   ADD OBJECT olecontrol1 AS OLECONTROL WITH ;
      TOP = 24, ;
      LEFT = 12, ;
      HEIGHT = 276, ;
      WIDTH = 612, ;
      NAME = "Olecontrol1", ;
      OLECLASS = "DHTMLEdit.DHTMLEdit.1"

   ADD OBJECT text1 AS TEXTBOX WITH ;
      VALUE = "http://www.msn.com", ;
      HEIGHT = 25, ;
      LEFT = 24, ;
      TOP = 408, ;
      WIDTH = 577, ;
      NAME = "Text1"

   ADD OBJECT command1 AS COMMANDBUTTON WITH ;
      TOP = 324, ;
      LEFT = 24, ;
      HEIGHT = 25, ;
      WIDTH = 145, ;
      CAPTION = "\<Navigate", ;
      NAME = "Command1"

ENDDEFINE
  2. Save and run the program file, and note that after the fifth iteration, a fatal exception error may occur.

REFERENCES

For additional information, query the Visual FoxPro Help Files; search on "AutoYield."
(c) Microsoft Corporation 2000, All Rights Reserved. Contributions by John Desch, Microsoft Corporation.

Modification Type:MajorLast Reviewed:10/15/2002
Keywords:kbBug kbCodeSnippet kbCtrl kbDSupport KB266363
©2002 Microsoft Corporation. All rights reserved.