Hi,

Are you making the assumption that the grid rows will always be the same? What happens if a user sorts a column in one grid? Or applies filtering to one of the grids?

Assuming that neither of those is enabled, then you would have to find the parent row of the active row first in order to find the matching child row.

        private void ultraGrid_AfterRowActivate(object sender, EventArgs e)
        {
            UltraGrid grid = (UltraGrid)sender;
            UltraGrid otherGrid = grid == this.ultraGrid1
                ? this.ultraGrid1
                : this.ultraGrid2;
            
            // Disable this event to prevent recursion
            grid.EventManager.SetEnabled(GridEventIds.AfterRowActivate, false);
            otherGrid.EventManager.SetEnabled(GridEventIds.AfterRowActivate, false);

            try
            {
                UltraGridRow activeRow = grid.ActiveRow;
                if (activeRow == null)
                {
                    // If there is no activerow, just clear the ActiveRow in the other grid. 
                    otherGrid.ActiveRow = null;
                    return;
                }

                UltraGridBand band = activeRow.Band;
                if (band.Index == 0)
                {
                    // If the active row is in band 0, it's very easy to find. 
                    otherGrid.Rows[activeRow.Index].Activate();
                    return;
                }

                // If we reach this code, then the active row is a child row. So first find the
                // matching parent row.
                UltraGridRow parentRow = activeRow.ParentRow;
                UltraGridRow otherParentRow = otherGrid.Rows[parentRow.Index];
                
                // Now that we have the matching parent row, we can activate the 
                // matching child row.
                otherParentRow.ChildBands[0].Rows[activeRow.Index].Activate();
                
            }
            finally
            {
                // Re-enabole this event.
                grid.EventManager.SetEnabled(GridEventIds.AfterRowActivate, true);
                otherGrid.EventManager.SetEnabled(GridEventIds.AfterRowActivate, true);
            }
        }