DataView dvGrade = new DataView(dtScore);//没排序啊,烦……
dvGrade.Sort = "Mark DESC"; for(int m = 0;m < dvGrade.Count;m ++)
{
int nNo = m + 1;
dtScore.Rows[m]["No"] = nNo.ToString();
DataRowView dtv = dvGrade[m];
dtScore.Rows[m]["Name"] = dtv["Name"].ToString();
dtScore.Rows[m]["Mark"] = Convert.ToDouble(dtv["Mark"]);
}