Can you post a small sample project demonstrating this behavior? I tried it out and it works correctly for me.

My guess is that there is some other factor at work here, like something in your code that is causing the header checkbox to get out of synch.

Hi, Chris,

It was exactly what i was looking for. 

Thank you very much.

Hello Bishwa,

The functionality you are trying to achieve can be handled with a little bit of code in the UltraGrid's BeforeHeaderCheckStateChanged event handler, by calling SetHeaderCheckedState() on child RowsCollections for each row in e.Rows if it is a UltraGridGroupByRow. With the HeaderCheckBoxSynchronization set to RowsCollection, use the following code:

        private void ultraGrid1_BeforeHeaderCheckStateChanged(object sender, BeforeHeaderCheckStateChangedEventArgs e)
        {
            // If the rows in the Rows collection are GroupByRows, 
            // then call SetHeaderCheckedState on the child RowsCollection
            // Check IsCancelable to make sure we are only doing this when the Header CheckBox is clicked, not during synchronization.
            if (e.IsCancelable && 
                e.NewCheckState != CheckState.Indeterminate &&
                e.Rows != null &&
                e.Rows.Count > 0 &&
                e.Rows[0].IsGroupByRow)
            {
                int numRows = e.Rows.Count;
                for (int i = 0; i < numRows; i++)
                {
                    UltraGridGroupByRow groupByRow = e.Rows[i] as UltraGridGroupByRow;
                    e.Column.SetHeaderCheckedState(groupByRow.Rows, e.NewCheckState);
                }
            }
        }

This will hopefully meet your needs. Let me know if you require further assistance.

Thanks,

Chris