fang1004tw

        bool isExpand = true;
        private void simpleButton3_Click(object sender, EventArgs e)
        {
            ExpandAllRows(gridView1 , isExpand);
            isExpand = ! isExpand;
        }

        public void ExpandAllRows(DevExpress.XtraGrid.Views.Grid.GridView view ,bool Expand)
        {
            view.BeginUpdate();
            try
            {
                int dataRowCount = view.DataRowCount;
                for (int rHandle = 0; rHandle < dataRowCount; rHandle++)
                    view.SetMasterRowExpanded(rHandle, Expand);
            }
            finally
            {
                view.EndUpdate();
            }
        }