LINQ to SQL ,直接在datagridview中修改，结合使用submitchange()

思路是：

直接将IQueryable<T>绑定到BindingSource
再把BindingSource绑定到DataGridView
这样就可以直接用DataContext.SubmitChanges()来向数据库提交更改

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace _18
{
public partial class Form1 : Form
{
booksDataClassesDataContext bookstore = new booksDataClassesDataContext();

public Form1()
{

InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
this.book_infoDataGridView.DataSource = this.bookstore.book_info;
BindingSource bds = new BindingSource();
bds.DataSource = this.bookstore.book_info;
this.book_infoBindingSource = bds;
this.book_infobindingNavigator.BindingSource = bds;

}

private void save_Click(object sender, EventArgs e)
{
//this.book_infoBindingSource.EndEdit();
this.book_infoDataGridView.EndEdit();
var bookquery = from booked in bookstore.book_info
select booked;
////将泛型集合IQueryable<T>的 bookquery对象集赋给DataGridView
this.book_infoDataGridView.DataSource = bookquery;

bookstore.SubmitChanges();
}
}
}