LinQ的组合+分页

前台代码：

        名称：<asp:TextBox ID="Textname" runat="server"></asp:TextBox>
        油耗：<asp:TextBox ID="Textoil" runat="server"></asp:TextBox>
        马力：<asp:TextBox ID="Textpowers" runat="server"></asp:TextBox>
        <asp:Button ID="btncha" runat="server" Text="查询" /><br /><br />

当前第[<asp:Label ID="lb_now" runat="server" Text="0"></asp:Label>]页，共[<asp:Label ID="lb_all" runat="server" Text="0"></asp:Label>]页
        <asp:LinkButton ID="btnfirst" runat="server">首页</asp:LinkButton>
        <asp:LinkButton ID="btn_prev" runat="server">上一页</asp:LinkButton> <asp:LinkButton ID="btn_next" runat="server">下一页</asp:LinkButton>
        <asp:LinkButton ID="btnlast" runat="server">末页</asp:LinkButton>
        <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="true"></asp:DropDownList>

CarDA:数据访问类，

         mydbDataContext con = new mydbDataContext();
         public List<Car> Select()//查询表所有数据
            {
             return con.Car.ToList();
            }

 public List<Car> Selectname(string n)//查名称的方法
    {
        return con.Car.Where(r => r.Name.Contains(n)).ToList();
    }
    public List<Car> Selectoil(decimal o)//查油耗的方法
    {
        return con.Car.Where(r => r.Oil == o).ToList();
    }
    public List<Car> Selectpow(int p)//查马力的方法
    {
        return con.Car.Where(r => r.Powers == p).ToList();
    }

    public List<Car> Fenye(List<Car> list, int s, int t)//查分页的方法s是几条数据，t是几页
    {
        List<Car> li = con.Car.ToList();//查到所有数据
        return li.Intersect(list).Skip(s * t).Take(t).ToList();
    }

后台代码：

  int pagenum = 3;//每页显示三页
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            Repeater1.DataSource = new CarDA().Select().Take(pagenum);
            Repeater1.DataBind();
            lb_now.Text = "1";//定义打开显示第一页
            lb_all.Text = Math.Ceiling(Convert.ToDouble(new CarDA().Select().Count) / pagenum).ToString();//上限  最大页数   总条数÷一页显示的条数= 总共的页数

            for (int i = 1; i <= Convert.ToInt32(lb_all.Text); i++)
            {
                ListItem li = new ListItem(i.ToString(), i.ToString());
                DropDownList1.Items.Add(li);//跳转
            }
        }
       
       


        btncha.Click += btncha_Click;//查询

        btn_prev.Click += btn_prev_Click;//上一页
        btn_next.Click += btn_next_Click;//下一页
        btnfirst.Click += btnfirst_Click;//首页
        btnlast.Click += btnlast_Click;//末页
        DropDownList1.SelectedIndexChanged += DropDownList1_SelectedIndexChanged;//跳转
    }

    void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {//跳转

        int n = Convert.ToInt32(DropDownList1.SelectedItem.Text);//获取索引最小的选定向

        lb_now.Text = n.ToString();//当前页数
        CarDA ca = new CarDA();
        List<Car> list = ca.Select();

        if (Textname.Text != "")
        {
            List<Car> list1 = ca.Selectname(Textname.Text);
            list = list.Intersect(list1).ToList();
        }
        if (Textoil.Text != "")
        {
            List<Car> list1 = ca.Selectoil(Convert.ToDecimal(Textoil.Text));
            list = list.Intersect(list1).ToList();
        }
        if (Textpowers.Text != "")
        {
            List<Car> list1 = ca.Selectpow(Convert.ToInt32(Textpowers.Text));
            list = list.Intersect(list1).ToList();
        }

        lb_all.Text = Math.Ceiling(Convert.ToDouble(list.Count) / pagenum).ToString();
        Repeater1.DataSource = ca.Fenye(list, (Convert.ToInt32(lb_now.Text) - 1), pagenum);
        Repeater1.DataBind();  
    }

    void btnlast_Click(object sender, EventArgs e)
    {//末页
        CarDA ca = new CarDA();
        List<Car> list = ca.Select();

        if (Textname.Text != "")
        {
            List<Car> list1 = ca.Selectname(Textname.Text);
            list = list.Intersect(list1).ToList();
        }
        if (Textoil.Text != "")
        {
            List<Car> list1 = ca.Selectoil(Convert.ToDecimal(Textoil.Text));
            list = list.Intersect(list1).ToList();
        }
        if (Textpowers.Text != "")
        {
            List<Car> list1 = ca.Selectpow(Convert.ToInt32(Textpowers.Text));
            list = list.Intersect(list1).ToList();
        }
        lb_now.Text = Math.Ceiling(Convert.ToDouble(list.Count) / pagenum).ToString();
        lb_all.Text = Math.Ceiling(Convert.ToDouble(list.Count) / pagenum).ToString();
        Repeater1.DataSource = ca.Fenye(list, (Convert.ToInt32(lb_now.Text) - 1), pagenum);
        Repeater1.DataBind();  
    }

    void btnfirst_Click(object sender, EventArgs e)
    {//首页
        lb_now.Text = "1";
        CarDA ca = new CarDA();
        List<Car> list = ca.Select();

        if (Textname.Text != "")
        {
            List<Car> list1 = ca.Selectname(Textname.Text);
            list = list.Intersect(list1).ToList();
        }
        if (Textoil.Text != "")
        {
            List<Car> list1 = ca.Selectoil(Convert.ToDecimal(Textoil.Text));
            list = list.Intersect(list1).ToList();
        }
        if (Textpowers.Text != "")
        {
            List<Car> list1 = ca.Selectpow(Convert.ToInt32(Textpowers.Text));
            list = list.Intersect(list1).ToList();
        }

        lb_all.Text = Math.Ceiling(Convert.ToDouble(list.Count) / pagenum).ToString();
        Repeater1.DataSource = ca.Fenye(list, (Convert.ToInt32(lb_now.Text) - 1), pagenum);
        Repeater1.DataBind();
       
    }

    void btn_next_Click(object sender, EventArgs e)
    {//下一页
        
        int a =Convert.ToInt32( lb_now.Text)+1;每点一下加1
        
        CarDA ca = new CarDA();
        List<Car> list = ca.Select();

        if (Textname.Text != "")
        {
            List<Car> list1 = ca.Selectname(Textname.Text);
            list = list.Intersect(list1).ToList();
        }
        if (Textoil.Text != "")
        {
            List<Car> list1 = ca.Selectoil(Convert.ToDecimal(Textoil.Text));
            list = list.Intersect(list1).ToList();
        }
        if (Textpowers.Text != "")
        {
            List<Car> list1 = ca.Selectpow(Convert.ToInt32(Textpowers.Text));
            list = list.Intersect(list1).ToList();
        }
        lb_now.Text = a.ToString();//让现在的页数显示+1之后的数据
        lb_all.Text = Math.Ceiling(Convert.ToDouble(list.Count) / pagenum).ToString();
        Repeater1.DataSource = ca.Fenye(list, (Convert.ToInt32(lb_now.Text) - 1), pagenum);
        Repeater1.DataBind();
       
    }

    void btn_prev_Click(object sender, EventArgs e)
    {//上一页
        if (Convert.ToInt32(lb_now.Text) > 1)判断是否可以点上一页
        {
            int nownum = Convert.ToInt32(lb_now.Text) - 1;
            CarDA ca = new CarDA();
            List<Car> list = ca.Select();

            if (Textname.Text != "")
            {
                List<Car> list1 = ca.Selectname(Textname.Text);
                list = list.Intersect(list1).ToList();
            }
            if (Textoil.Text != "")
            {
                List<Car> list1 = ca.Selectoil(Convert.ToDecimal(Textoil.Text));
                list = list.Intersect(list1).ToList();
            }
            if (Textpowers.Text != "")
            {
                List<Car> list1 = ca.Selectpow(Convert.ToInt32(Textpowers.Text));
                list = list.Intersect(list1).ToList();
            }

            Repeater1.DataSource = ca.Fenye(list, (nownum - 1), pagenum);
            Repeater1.DataBind();
            lb_now.Text = nownum.ToString();
        }
    }

    void btncha_Click(object sender, EventArgs e)
    {//查询
        lb_now.Text = "1";
        int nownum = Convert.ToInt32(lb_now.Text);
        CarDA ca = new CarDA();
        List<Car> list = ca.Select();

        if (Textname.Text != "")
        {
            List<Car> list1 = ca.Selectname(Textname.Text);
            list = list.Intersect(list1).ToList();
        }
        if (Textoil.Text != "")
        {
            List<Car> list1 = ca.Selectoil(Convert.ToDecimal(Textoil.Text));
            list = list.Intersect(list1).ToList();
        }
        if (Textpowers.Text != "")
        {
            List<Car> list1 = ca.Selectpow(Convert.ToInt32(Textpowers.Text));
            list = list.Intersect(list1).ToList();
        }
        lb_all.Text = Math.Ceiling(Convert.ToDouble(list.Count) / pagenum).ToString();
        DropDownList1.Items.Clear();
        for (int i = 1; i <= Convert.ToInt32(lb_all.Text); i++)
        {
            ListItem li = new ListItem(i.ToString(), i.ToString());
            DropDownList1.Items.Add(li);
        }
        Repeater1.DataSource = ca.Fenye(list, (nownum - 1), pagenum);
        Repeater1.DataBind();
    }