1、在已有表头上添加自定义表头
精简后的伪代码如下：
1 e.Row.Cells.RemoveAt(0); 2 e.Row.Cells.AddAt(0, new TableHeaderCell()); 3 e.Row.Cells[0].ColumnSpan = 3; 4 e.Row.Cells[0].Text = "Row1</th></tr><tr><th>Row2</th></tr><tr><th>Original Row1 Cell1";
