取DataTable某一列的最大值
1.datatable.compute("max(列名)","")
2.Column.Expression = "max(数据列名)";
3.用视图来排序
Dim firstView As DataView
Dim maxvalue as string
firstView = dt.DefaultView
firstView.Sort = "数据列名 DESC"
maxvalue = firstView.Item(0).Item(0)
4.tbl.Select("", "columnName Asc")(0)(columnName)