I hope I solved the problem - the datatable should be created as a new object every time I want to change the columns in grid group.

Hi,

 I have the same problem as Karen, I tried to solve it as you wrote in the post, but it doesn't work:( It's my code :

dataTable is of type DataTable. I want only to get rid of these grid columns, which have index greater than 2. When I launch my form, it works fine, but if I reload it because of data change, it throws an exception attached. It seems this exception occurs in grid.OnPaint event It's my code: 

UltraGridBand band = grid.DisplayLayout.Bands[0];
UltraGridGroup group = band.Groups[1];
UltraGridColumn col;
for (int i = 3; i < dataTable.Columns.Count; i++)
{
        String colKey = dataTable.Columns[i].Caption;
        if (!grid.DisplayLayout.Bands[0].Columns.Exists(colKey))
        {
             col = grid.DisplayLayout.Bands[0].Columns.Add(colKey);
             col.DataType = typeof(decimal);
         }
         else
             col = grid.DisplayLayout.Bands[0].Columns[colKey];
               
         if (!group.Columns.Exists(colKey))
             col.Group = group;
}

Thanks,

~Gosia

 Karen,

You're getting an exception because you're trying to add a column to a group that already contains a column with that key.  The code I changed in the LayoutGrid method is:

         'create columns for each column key
        Dim col As Infragistics.Win.UltraWinGrid.UltraGridColumn
        For Each key As String In myColumnKeys
            If grid.DisplayLayout.Bands(0).Columns.Exists(key) = False Then
                col = grid.DisplayLayout.Bands(0).Columns.Add(key)
                col.DataType = GetType(System.Boolean)
                col.DefaultCellValue = False
                col.Style = Infragistics.Win.UltraWinGrid.ColumnStyle.CheckBox

                Dim group As UltraGridGroup = grid.DisplayLayout.Bands(0).Groups("X Vals")
                If group.Columns.Exists(col.Key) = False Then
                    col.Group = group
                End If                
            End If
        Next key

-Matt

Hi Matt,

One other note on this problem...

If I don't try to put my columns in UltraGridGroups, I don't have any problems.

Thanks Matt, but the columns I'm trying to get rid of are NOT bound.  I have 2 Bound columns columns, but then a few unbound columns that I want to clear out.  I have attached a sample grid that shows my problem.  Try running it, and then change the number of rows or columns that are supposed to show.  You'll hit the error that way.

Thanks again for the help,

~Karen