DOCUMENT:Q221702 20-MAY-1999 [foxpro] TITLE :FIX: C0000005 Fatal Error w/ ISBLANK( ) and Array Prop in Init PRODUCT :Microsoft FoxPro PROD/VER:WINDOWS:5.0a,6.0 OPER/SYS: KEYWORDS:kbservicepack kbContainer kbCtrl kbOOP kbvfp500aBUG kbvfp600 kbvfp600bug kbXBase kbVS60 ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual FoxPro for Windows, versions 5.0a, 6.0 ------------------------------------------------------------------------------- SYMPTOMS ======== Placing an ISBLANK() function in the Init of a form created programmatically causes the following error in Visual FoxPro 6.0: Fatal Error C0000005 In Visual FoxPro 5.0x, the following error appears: An application has occurred and an application error log is being generated. VFP.exe Exception: access violation(0xc0000005); address: If the ISBLANK() function is in the Init event of a form create with the Form Designer, no error occurs but the Show event of the form never fires. Therefore, the form flashes and disappears. RESOLUTION ========== To work around this behavior, put parentheses around the array variable. In the example below, this works: IIF(isblank((THISFORM.WorkerData[2])) while this does not: IIF((isblank(THISFORM.WorkerData[2])) In Steps to Reproduce Behavior below, comment and uncomment the specified lines of code as indicated in the example and it operates as expected. STATUS ====== Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information about Visual Studio service packs, please see the following articles in the Microsoft Knowledge Base: Q194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why Q194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed MORE INFORMATION ================ Steps to Reproduce Behavior --------------------------- 1. Create a program that contains the following code: ***Code begins here PUBLIC oisblkerr oisblkerr=CREATEOBJECT("arrform") oisblkerr.SHOW READ EVENTS RELEASE oisblkerr RETURN DEFINE CLASS arrform AS FORM DIMENSION myar[3],larray[4,3] ADD OBJECT text1 AS TEXTBOX ADD OBJECT cmdexit AS COMMANDBUTTON cmdexit.TOP = THISFORM.text1.TOP+THISFORM.text1.HEIGHT+10 text1.width=150 PROCEDURE init THISFORM.myar[1]="John" THISFORM.myar[2]="X." THISFORM.myar[3]="Smith"
* Comment this line below to prevent problem. THISFORM.text1.VALUE = ALLTRIM(THISFORM.myar[1])+" "+IIF(isblank(THISFORM.myar[2]),; "",THISFORM.myar[2])+ " "+RTRIM(THISFORM.myar[3])
* Uncomment these lines below for it to work properly *!* THISFORM.text1.VALUE = ALLTRIM(THISFORM.myar[1])+" "+IIF(isblank((THISFORM.myar[2])),; *!* "",THISFORM.myar[2])+ " "+RTRIM(THISFORM.myar[3]) ENDPROC PROCEDURE cmdexit.CLICK THISFORM.RELEASE CLEAR EVENTS RETURN ENDPROC ENDDEFINE 2. Run the program. Depending on what code is commented, the form either appears or Visual FoxPro crashes with one of the errors mentioned in the Symptoms section. To see the behavior in a form created with the Form Designer, follow these steps: 1. Create a form. 2. Add the property "WorkerName" to the form. This will store the concatenated name. 3. Add the property "WorkerData[3]" to the form. This is an array to store the parts of the name. 4. In the Init event of the form, add the following code: THISFORM.WorkerData[1] = "JOHN" THISFORM.WorkerData[2] = "X" THISFORM.WorkerData[3] = "SMITH" * This code causes the error THISFORM.WorkerName = THISFORM.WorkerData[1] + ; IIF((isblank(THISFORM.WorkerData[2])), " ", " " + THISFORM.WorkerData[2] + " "); + THISFORM.WorkerData[3] * This code does not cause the error *!* THISFORM.WorkerName = THISFORM.WorkerData[1] + ; *!* IIF(isblank((THISFORM.WorkerData[2])), " ", " " + THISFORM.WorkerData[2] + " "); *!* + THISFORM.WorkerData[3] 5. Save the form and run it. Notice that the form flashes and disappears. 6. Modify the form and edit the Init event. Comment the code that causes the error and uncomment the code that functions properly. 7. Run the form and notice that it appears on the screen. Additional query words: ====================================================================== Keywords : kbservicepack kbContainer kbCtrl kbOOP kbvfp500aBUG kbvfp600 kbvfp600bug kbXBase kbVS600sp2 kbVS600SP1 kbVS600sp3fix kbGrpDSFox Technology : kbVFPsearch kbAudDeveloper kbVFP600 kbVFP500a Version : WINDOWS:5.0a,6.0 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 1999.