dt = dt.AsEnumerable().OrderByDescending(x=>x.Field<decimal>("C_ID")).ThenByDescending(x=>x.Field<decimal>("C_NAME")) .Select(x=>x) .CopyToDataTable();
dt = dt.Select("1=1").OrderByDescending(x=>x["C_ID"]).ThenByDescending(x=>x.["C_NAME"]) .CopyToDataTable();
先按C_ID倒叙再按C_NAME正序然后转成Datatable