Datatable 中数据怎么排序 DataTable dt3 = new DataTable();
            dt3.TableName = "dt3";
            dt3.Columns.Add("filepath", Type.GetType("System.String"));            dt3.Columns.Add("size", Type.GetType("System.Double"));            DataRow dr1 = dt3.NewRow();
            dr1["filepath"] = "\\d:AA\\";
            dr1["size"] = 0;
            dt3.Rows.Add(dr1);            DataRow dr2 = dt3.NewRow();
            dr2["filepath"] = "\\d:AA\\1.jpg";
            dr2["size"] = 100;
            dt3.Rows.Add(dr2);            DataRow dr3 = dt3.NewRow();
            dr3["filepath"] = "\\d:BB\\";
            dr3["size"] = 0;
            dt3.Rows.Add(dr3);            DataRow dr4 = dt3.NewRow();
            dr4["filepath"] = "\\d:BB\\1.jpg";
            dr4["size"] = 200;
            dt3.Rows.Add(dr4);
现在的数据就是
\\d:AA\\           0
\\d:AA\\1.jpg  100
\d:BB\\            0
\\d:BB\\1.jpg  200
而我想先根据跟目录长短排序,再根据 size 由大变小我要得到
\\d:AA\\           0
\d:BB\\            0
\\d:BB\\1.jpg  200
\\d:AA\\1.jpg  100
c#怎么完成这个功能
private DataTable  do(DataTable t1)
{
????
return t2;
}