添加合计行

//添加合计列
DataTable dt = ds.Tables[0];
if (dt != null && dt.Rows.Count > 0)
{
DataRow dr = dt.NewRow();

dr[0] = "合计";
dr[1] = dt.Compute("sum(短信)", "");
dr[2] = dt.Compute("sum(电子邮件)", "");
dr[3] = dt.Compute("sum(电话)", "");
dr[4] = dt.Compute("sum(传真)", "");

dt.Rows.Add(dr);
}