NorthwindDBDataContext dc = new NorthwindDBDataContext();

    protected void Page_Load(object sender, EventArgs e)

    {

        if (IsPostBack)

            return;

        Bind();

    }

    /// <summary>

    /// 绑定数据

    /// </summary>

    private void Bind()

    {

        GridView1.DataSource = dc.Users;

        GridView1.DataBind();

    }

    /// <summary>

    /// 添加

    /// </summary>

    /// <param name="sender"></param>

    /// <param name="e"></param>

    protected void Button1_Click(object sender, EventArgs e)

    {

        //把需要的值存起来

        string name = TextBox1.Text;

        string pass = TextBox2.Text;

        bool sex = CheckBox1.Checked;

        Users user = new Users() { UserName = name, UserPwd = pass, Sex = sex }; //初始化一个用户类

        dc.Users.InsertOnSubmit(user); //提交数据

        //List<Users> list = new List<Users>() { user };//生成一个用户集合

        //dc.Users.InsertAllOnSubmit(list);    //提交数据

        dc.SubmitChanges();  //对数据库进行修改

        Bind();

    }

    /// <summary>

    /// 删除

    /// </summary>

    /// <param name="sender"></param>

    /// <param name="e"></param>

    protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)

    {

        //把需要删除的ID找到

        string id = GridView1.DataKeys[e.RowIndex].Value.ToString(); //ID进行过绑定

       ① var result = from u in dc.Users

                     where u.ID.ToString() == id

                     select u;    //把需要删除的行先找出来

        dc.Users.DeleteAllOnSubmit(result);   //删除多行     result 就是一个集合

        //dc.Users.DeleteOnSubmit(result.First());   删除单行

        dc.SubmitChanges();  //跟新数据库

        Bind();

    }

     ①=var result = dc.Users.Where((x) => x.ID.ToString() == id);  //相当于LINQ语句查询  确定是那张表where里面接Lambda表达式

 NorthwindDBDataContext dc = new NorthwindDBDataContext();

    protected void Page_Load(object sender, EventArgs e)

    {

        if (IsPostBack)

            return;

        string id = Request.QueryString["id"].ToString();   //拿到需要修改行的ID

        Users user = dc.Users.Where((x) => x.ID.ToString() == id).First();   //拿到需要修改的那行数据

        TextBox1.Text = user.UserName;

        TextBox2.Text = user.UserPwd;

        CheckBox1.Checked = user.Sex;

    }

    protected void Button1_Click(object sender, EventArgs e)

    {

        string id = Request.QueryString["id"].ToString();

        Users user = dc.Users.Where((x) => x.ID.ToString() == id).First(); //找到需要修改行，进行修改

        user.UserName = TextBox1.Text;

        user.UserPwd = TextBox2.Text;

        user.Sex = CheckBox1.Checked;

        dc.SubmitChanges();

        Response.Redirect("test.aspx");   //再回原来的页面

    }