Linq如何查询弱类型的Datatable

可以通过调用DataTable的扩展方法AsEnumerable方法，返回IEnumerable<T>对象，便于LINQ查询。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.OleDb;

public partial class Default3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        var products = from product in GetDataTable().AsEnumerable()
                       select new { ProductID = product.Field<int>("产品ID"), ProductName = product.Field<string>("产品名称")};
        this.GridView1.DataSource = products;
        this.GridView1.DataBind();
    }

    private DataTable GetDataTable()
    {
        DataTable table = new DataTable();
        using (OleDbConnection conn = new OleDbConnection("provider=microsoft.jet.oledb.4.0;data source=" + Server.MapPath("~/App_Data/Northwind.mdb")))
        {
            using (OleDbCommand comm = new OleDbCommand())
            {
                comm.Connection = conn;
                comm.CommandText = "SELECT * FROM Products";
                comm.CommandType = CommandType.Text;
                conn.Open();
                table.Load(comm.ExecuteReader(CommandBehavior.CloseConnection));
            }
        }
        return table;
    }
}