一、构建辅助列

 /// <summary>     /// 合并GridView中某列相同信息的行（单元格）     /// </summary>     /// <param name="GridView1">GridView</param>     /// <param name="cellNum">第几列</param>     public static void GroupRows(GridView GridView1, int cellNum)     {         int i = 0, rowSpanNum = 1;         while (i < GridView1.Rows.Count - 1)         {             GridViewRow gvr = GridView1.Rows[i];             for (++i; i < GridView1.Rows.Count; i++)             {                 GridViewRow gvrNext = GridView1.Rows[i];                 if (gvr.Cells[cellNum].Text == gvrNext.Cells[cellNum].Text)                 {                     gvrNext.Cells[cellNum].Visible = false;                     rowSpanNum++;                 }                 else                 {                     gvr.Cells[cellNum].RowSpan = rowSpanNum;                     rowSpanNum = 1;                     break;                 }                 if (i == GridView1.Rows.Count - 1)                 {                     gvr.Cells[cellNum].RowSpan = rowSpanNum;                 }             }         }     }