如何把返回的datatable按某个字段排序升序或者降序

DataTable dtdata = GetXmlData(doc, "DetailList").Tables[0];

//修改显示报告按审核时间AuthDate 倒序排列

DataTable dtCopy = dtdata.Copy();
DataView dv = dtdata.DefaultView;
dv.Sort = "AuthDate DESC";
dtCopy = dv.ToTable();
dtdata = dtCopy.Copy();