FIX: Access Violation or Page Fault with Multiple Toolbars

ID: Q191636

The information in this article applies to:

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

SYMPTOMS

When running code that instantiates, docks, and releases multiple toolbars, you may see an error similar to the following under Windows NT:

Exception: access violation (0xc0000005), Address: 0x77f7d514

The following error occurs under Windows 95:

VFP caused an invalid page fault in module KERNEL32.DLL at 0137:bff78053

STATUS

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

MORE INFORMATION

Steps to Reproduce Behavior

Run the following code from a program (.prg) file:


      #DEFINE    ARRAYSIZE       14
      DIMENSION oRef[ARRAYSIZE]
      FOR lni = 1 TO ARRAYSIZE
         oRef[lni] = CREATEOBJECT("Toolbar")
         oRef[lni].SHOW
         oRef[lni].DOCK(1)
         WAIT WINDOW "Creating "+ STR(lni) NOWA
      ENDFOR
      WAIT CLEAR
      FOR lni = 1 TO ARRAYSIZE
         WAIT WINDOW "Releasing "+ STR(lni) NOWA
         oRef[lni] = .NULL. && Use this in VFP 5, 3.0b
      ENDFOR
      WAIT CLEAR

Under Windows NT, you see an error like the following:

Exception: access violation (0xc0000005), Address: 0x77f7d514

Under Windows 95, you will see an error like the following:

VFP caused an invalid page fault in module KERNEL32.DLL at 0137:bff78053

NOTE: It may take multiple runs of the preceding program before you see the error occur in Windows 95.

REFERENCES

Additional query words: kbVFp300bbug kbVFp500abug kbVFp600fix kbXBase kbfvp600fix

Keywords :
Version : WINDOWS:3.0,3.0b,5.0,5.0a
Platform : WINDOWS
Issue type : kbbug