Devexpress中Gridcontrol查找分组

         private void button1_Click(object sender, EventArgs e)
         {
             DataTable dt = new DataTable();
             dt.Columns.Add("Group");
             dt.Columns.Add("idex");
             dt.Columns.Add("name");
             for (int i = ; i < ; i++)
             {
                 DataRow dr = dt.NewRow();
                 dr["Group"] = "<5";
                 dr["idex"] = i.ToString();
                 dr["name"] = "姓名" + i.ToString();
                 dt.Rows.Add(dr);
             }
             for (int i = ; i <= ; i++)
             {
                 DataRow dr = dt.NewRow();
                 dr["Group"] = "(5,10]";
                 dr["idex"] = i.ToString();
                 dr["name"] = "姓名" + i.ToString();
                 dt.Rows.Add(dr);
             }
             for (int i = ; i <= ; i++)
             {
                 DataRow dr = dt.NewRow();
                 dr["Group"] = "(10,15]";
                 dr["idex"] = i.ToString();
                 dr["name"] = "姓名" + i.ToString();
                 dt.Rows.Add(dr);
             }

             gridColumnNumber.FieldName = "idex";
             gridColumnName.FieldName = "name";
             gridColumnGroup.FieldName = "Group";
             gridColumnGroup.GroupIndex = ;
             gdc.DataSource = dt;
             gdv.ExpandAllGroups();

             for (int i = -; gdv.IsGroupRow(i); i--)
             {
                 DataRow dr = gdv.GetDataRow(gdv.GetDataRowHandleByGroupRowHandle(i));
                 if (dr == null) return;
                 if (dr["Group"].ToString() == "(5,10]")
                 {
                     gdv.CollapseAllGroups();
                     gdv.FocusedRowHandle = i;
                     gdv.SetRowExpanded(i, true);
                     return;
                 }
             }
         }