Microsoft KB Archive/171835

= FIX: Crash When Viewing Data Tips on ParamArray =

Article ID: 171835

Article Last Modified on 12/10/2003

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APPLIES TO


 * Microsoft Visual Basic 5.0 Control Creation Edition
 * Microsoft Visual Basic 5.0 Learning Edition
 * Microsoft Visual Basic 5.0 Professional Edition
 * Microsoft Visual Basic 5.0 Enterprise Edition

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This article was previously published under Q171835



SYMPTOMS
A crash may occur while trying to display Data Tips in the IDE. This can occur when you have a variant that contains an array of non-variants and pass the element of that array to a ParamArray.



STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug has been fixed in Visual Studio 97 Service Pack 2.

For more information on the Visual Studio 97 Service Pack 2, please see the following article in the Microsoft Knowledge Base:

170365 INFO: Visual Studio 97 Service Packs - What, Where, and Why

For a list of the Visual Basic 5.0 bugs that were fixed in the Visual Studio 97 Service Pack 2, please see the following article in the Microsoft Knowledge Base:

171554 INFO: Visual Basic 5.0 Fixes in Visual Studio 97 Service Pack 2



Steps to Reproduce Behavior
 Start a new Standard EXE Project in Visual Basic 5.0. Click on Project | Add Module to add a basic module to the project. Note that if you have Visual Basic 5.0 set up to automatically include "Option Explicit" to new modules, remove this line.  In the General Declarations area of the module, add the following code: Sub main Dim x(5) as integer v = x         r = Formt("????", v(5)) End Sub

Public Function Formt(str As String, ParamArray rgArgs) As String Dim var As Variant Dim iPos As Integer, iLastPos As Integer Dim strRet As String

iPos = 0 iLastPos = 1 For Each var In rgArgs iPos = InStr(iPos + 1, str, "?") If iPos < 1 Then Exit For strRet = strRet & Mid(str, iLastPos, iPos - iLastPos) strRet = strRet & var iLastPos = iPos + 1 Next

If Len(str) > iPos Then strRet = _ strRet & Right(str, Len(str) - (iPos))

Formt = strRet End Function  From the Project menu select the Project1.Properties. On the General tab, make Sub Main the Startup Object. Press the F5 key to run this program. You will get a Type Mismatch error. Click on the dialog's Debug button.</li>  In the following line of code: strRet = strRet & Mid(str, iLastPos, iPos - iLastPos) move the mouse pointer over the variable str to display the Data Tips. Once the Data Tip for this variable has been displayed, move to the next variable, iLastPos, to display its Data Tip. Go back and forth between the two variables several times. </li>  Go to the following line of code: Public Function Format(str As String, ParamArray rgArgs) _ As String and move the mouse pointer over rgArgs. At this point an Invalid Page Fault and an application error in Visual Basic is displayed. </li></ol>

Keywords: kbbug kbfix kbvbp500sp2fix kbvs97sp2fix KB171835

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