GridView中访问单元格

在protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)事件中
1.访问可写列：string newname =((TextBox)GridView1.Rows[e.RowIndex].Cells[2].Controls[0]).Text;
2.访问只读列：string tid = GridView1.Rows[e.RowIndex].Cells[1].Text;