Null Reference Exception unhandled

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VS2008

Hi!

I'm getting Null Reference Exception unhandled error. The error shows: "Object reference not set to an instance of an object" on the line

j=localgroupdata.Tables("GroupTable").Rows.Count()

If I set j=10, the error shows on i:
For i = 0 To (j - 1)

Please help me.

***************************************

VB

Private Sub FillListbox()
    Dim i, j As Integer
    Dim localGroup As New Group()
    localgroupdata = localGroup.GetGroups()
    localGroup = Nothing
    j = localgroupdata.Tables("GroupTable").Rows.Count()
    For i = 0 To (j - 1)
        lstGroups.Items.Add(localgroupdata.Tables(0).Rows(i)(0))
    Next
    lstGroups.SelectedIndex = 0
End Sub

**************************************

Thanks!

Posted 12-Jan-11 21:21pm

kumarsajith01

Updated 12-Jan-11 21:46pm

Dalek Dave

v2

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Dalek Dave 13-Jan-11 3:46am

Edited for Readability.

justinonday 13-Jan-11 5:17am

check j's value comming??

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CPallini · Accepted Answer · 2011-01-12T21:25:00

Solution 1

You didn't check the localGroup.GetGroups() return value, namely localgroupdata.
:)

Posted 12-Jan-11 21:25pm

CPallini

Comments

kumarsajith01 13-Jan-11 3:43am

when I debug, it shows nothing as value. How to solve this problem? Shall I use IF..? Could you suggest detailed correction to the code

CPallini 13-Jan-11 3:48am

Of course you should avoid to reference a 'nothing' object. You may use a condition (like you said) or you may just handle the exeception. In any case, why is it 'nothing' (I mean are you sure you should get it on a freshly created 'Group'?)?

kumarsajith01 13-Jan-11 3:57am

Thank you very much. I'll recode it.