Linq to DataSet查询

首先手动建个DataSet

public DataSet BulidDataSet()

        {

            DataSet ds=new DataSet();

            DataTable dt = new DataTable();

            DataColumn col = new DataColumn("姓名",typeof(string));

            col.MaxLength = 20;

            dt.Columns.Add(col);                   //注意是dt.columns 然后ADD

            DataColumn col1 = new DataColumn("年龄", typeof(int));

            col.MaxLength = 20;

            dt.Columns.Add(col1);

            DataRow rw =dt.NewRow();          //给DT增加一个新行对象

            rw["姓名"] = "aking";

            rw["年龄"] = 26;

            dt.Rows.Add(rw);                         //   dt.Rows.Add(dt.NewRow());   增加一个空

            DataRow rw1 = dt.NewRow();

            rw1["姓名"] = "yao";

            rw1["年龄"] = 26;

            dt.Rows.Add(rw1);

            DataRow rw2 = dt.NewRow();

            rw2["姓名"] = "Ayao";

            rw2["年龄"] = 26;

            dt.Rows.Add(rw2);

            ds.Tables.Add(dt);

            return ds;

        }
   Linq查询部分
DataTable persons=ds.Tables[0];
  var num1=from p in persons.AsEnumerable() where p.Field<int>("姓名") ==“yao”
                     select new {
                         ID=p.Field<int>("ID")
        };