> I am trying to set a tooltip for a column cell in a data grid as
> documented in the MS Visual Studio 2005 documentation.  I set up a test
> to match the example exactly including database column, data grid
> column and data values.  I also have a tooltip control on the form.  If
> I comment out the 'if' test, it works fine, but uncommented, I get a
> NullReferenceException error on the
> Me.dataGridView1.Columns("Rating").Index reference.  Here is the code
> snippet from the help doc:
>
> ' Sets the ToolTip text for cells in the Rating column.
> Sub dataGridView1_CellFormatting(ByVal sender As Object, _
>     ByVal e As DataGridViewCellFormattingEventArgs) _
>     Handles dataGridView1.CellFormatting
>
>     If e.ColumnIndex = Me.dataGridView1.Columns("Rating").Index _
>         AndAlso Not (e.Value Is Nothing) Then
>
>         With Me.dataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex)
>
>             If e.Value.Equals("*") Then
>                 .ToolTipText = "very bad"
>             ElseIf e.Value.Equals("**") Then
>                 .ToolTipText = "bad"
>             ElseIf e.Value.Equals("***") Then
>                 .ToolTipText = "good"
>             ElseIf e.Value.Equals("****") Then
>                 .ToolTipText = "very good"
>             End If
>
>         End With
>
>     End If
>
> End Sub 'dataGridView1_CellFormatting
>
>
> I'm new to vb.net, so be kind :-)
>
> Thanks for the help.

> rowe_newsgroups wrote:
> > Well, lets check the simple cause first. Does the column named "Rating"
> > exist when this code executes?
> >
> > Thanks,
> >
> > Seth Rowe
> >
>
> Yes it does.  It is visible in the column properties within the
> datagridview.

> Are you adding the Rating Column with code or by using the "Add Column"
> dialog in design view? Also what are you putting in for the Name
> property and the Header Text property of the column? I used the
> following in my form_load event to add the "Rating" column and
> everything works fine.
>
>         DataGridView1.Columns.Add("Rating", "Rating")
>         Dim values() As String = {"*", "**", "***", "****"}
>         For i As Integer = 0 To 4
>             DataGridView1.Rows.Add(values(i))
>         Next i
>
> Let me know what you find out.
>
> Thanks,
>
> Seth Rowe
>
>