zoukankan html css js c++ java

2017-6-2 Linq 高级查询（分页和组合查）、集合取交集

1、linq分页和组合查询：（用项目实战来解释）

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
        用户名：<asp:TextBox ID="txt_uname" runat="server"></asp:TextBox>
        昵称：<asp:TextBox ID="txt_nick" runat="server"></asp:TextBox>
        性别：<asp:DropDownList ID="dr_sex" runat="server">
            <asp:ListItem Text="男" Value="True"></asp:ListItem>
            <asp:ListItem Text="女" Value="False"></asp:ListItem>
            <asp:ListItem Text="全部" Value="null"></asp:ListItem>
           </asp:DropDownList>
        <asp:Button ID="Button1" runat="server" Text="查询" />
   <table style="100%;text-align:center;background-color:navy;">
        <tr style="color:white;">
            <td>编号</td>
             <td>用户名</td>
             <td>密码</td>
             <td>昵称</td>
             <td>性别</td>
             <td>生日</td>
             <td>民族</td>
            <td>编辑</td>
        </tr>
        <asp:Repeater ID="Repeater1" runat="server">
            <ItemTemplate>
         <tr style="background-color:white;">
            <td><%#Eval("ids") %></td>
             <td><%#Eval("username") %></td>
             <td><%#Eval("password") %></td>
             <td><%#Eval("nickname") %></td>
             <td><%#Eval("sex") %></td>
             <td><%#Eval("birthday") %></td>
             <td><%#Eval("nation") %></td>
             <td>
                 <a href="update.aspx?id=<%#Eval("ids") %>">修改</a>
                 <a href="delete.aspx?id=<%#Eval("ids") %>">删除</a>
             </td>
        </tr>
                </ItemTemplate>
            </asp:Repeater>
    </table>
        当前第【<asp:Literal ID="lit_nownumber" Text="1" runat="server"></asp:Literal>】页，
        共【<asp:Literal ID="lit_max" runat="server"></asp:Literal>】页
        <asp:Button ID="btn_prev" runat="server" Text="上一页" />
        <asp:Button ID="btn_next" runat="server" Text="下一页" />
    </form>
</body>
</html>

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

public partial class _Default : System.Web.UI.Page
{
    int pagecount = 2;
    protected void Page_Load(object sender, EventArgs e)
    {
        Button1.Click += Button1_Click;
        btn_next.Click += btn_next_Click;
        btn_prev.Click += btn_prev_Click;
        if(!IsPostBack)
        {
            //using(masterDataContext con=new masterDataContext())
            //{
                Repeater1.DataSource = data().Take(pagecount);
                Repeater1.DataBind();
                
                //List<users> ulist = con.users.ToList();
                //Repeater1.DataSource = ulist.Skip(0).Take(pagecount);
                //排序：升序
               // Repeater1.DataSource = ulist.OrderBy(r=>r.ids);
                //排序：降序
                //Repeater1.DataSource = ulist.OrderByDescending(r=>Convert.ToDecimal(r.password));
                //开头：
                //Repeater1.DataSource = con.users.Where(r=>r.nickname.StartsWith("王"));
                    //结尾：
                //Repeater1.DataSource = con.users.Where(r => r.nickname.EndsWith("六"));
                 //模糊查（包含）：
                //Repeater1.DataSource = con.users.Where(r=>r.nickname.Contains("a"));
                  //个数：
                //Response.Write("总个数：" + ulist.Count+"<br/>");
                //     //最大值：
                //Response.Write("最大值：" + ulist.Max(r => Convert.ToDecimal(r.password)) + "<br/>");
                //     //最小值：
                //Response.Write("最小值：" + ulist.Min(r => Convert.ToDecimal(r.password)) + "<br/>");
                //         //平均值：
                //Response.Write("平均值：" + ulist.Average(r =>Convert.ToDecimal( r.password)) + "<br/>");
                //           //求和：
                //Response.Write("求和：" + ulist.Sum(r => Convert.ToDecimal(r.password)) + "<br/>");
                //Repeater1.DataBind();
                
            //}
        }
    }

  
    void btn_prev_Click(object sender, EventArgs e)
    {
        //using (masterDataContext con = new masterDataContext())
        //{
        //    int a = Convert.ToInt32(lit_nownumber.Text) - 1;
        //    Repeater1.DataSource = con.users.Skip((a - 1) * pagecount).Take(pagecount);
        //    Repeater1.DataBind();
        //    lit_nownumber.Text = a.ToString();
        //}
        int a = Convert.ToInt32(lit_nownumber.Text) - 1;
        Repeater1.DataSource = data().Skip((a - 1) * pagecount).Take(pagecount);
        Repeater1.DataBind();
        lit_nownumber.Text = a.ToString();
    }

    void btn_next_Click(object sender, EventArgs e)
    {
        //using (masterDataContext con = new masterDataContext())
        //{
        //    int a = Convert.ToInt32(lit_nownumber.Text) + 1;
        //    Repeater1.DataSource = con.users.Skip((a - 1) * pagecount).Take(pagecount);
        //    Repeater1.DataBind();
        //    lit_nownumber.Text = a.ToString();
        //}
        int a = Convert.ToInt32(lit_nownumber.Text) + 1;
        Repeater1.DataSource = data().Skip((a-1)*pagecount).Take(pagecount);
        Repeater1.DataBind();
        lit_nownumber.Text = a.ToString();
    }

    void Button1_Click(object sender, EventArgs e)
    {
       // using(masterDataContext con=new masterDataContext())
       // {
       //     List<users> ulist = con.users.ToList();
       //if(txt_uname.Text.Trim().Length>0)
       //{
       //    ulist = ulist.Where(r=>r.username.Contains(txt_uname.Text.Trim())).ToList();
       //}
       // if(txt_nick.Text.Trim().Length>0)
       // {
       //     ulist = ulist.Where(r => r.nickname.Contains(txt_nick.Text.Trim())).ToList();
       // }
       // if(dr_sex.SelectedValue!="null")
       // {
       //     ulist = ulist.Where(r => r.sex == Convert.ToBoolean(dr_sex.SelectedValue)).ToList();
       // }
       // Repeater1.DataSource = ulist;
       // Repeater1.DataBind();

       // }
        Repeater1.DataSource = data().Take(pagecount);
        Repeater1.DataBind();
        lit_nownumber.Text = "1";

    }

    public List<users> data() 
    {
        using (masterDataContext con = new masterDataContext())
        {
            List<users> ulist = con.users.ToList();
            if (txt_uname.Text.Trim().Length > 0)
            {
                ulist = ulist.Where(r => r.username.Contains(txt_uname.Text.Trim())).ToList();
            }
            if (txt_nick.Text.Trim().Length > 0)
            {
                ulist = ulist.Where(r => r.nickname.Contains(txt_nick.Text.Trim())).ToList();
            }
            if (dr_sex.SelectedValue != "null")
            {
                ulist = ulist.Where(r => r.sex == Convert.ToBoolean(dr_sex.SelectedValue)).ToList();
            }
            lit_max.Text = Convert.ToInt32(Math.Ceiling(Convert.ToDecimal(ulist.Count) / pagecount)).ToString();
            return ulist;
        }
    }

  
}

2、取集合交集：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    </div>
    </form>
</body>
</html>

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

public partial class Default2 : System.Web.UI.Page
{

    List<test1> tlist1 = new List<test1>();
    List<test1> tlist2 = new List<test1>();
    List<test1> tlist3 = new List<test1>();
    protected void Page_Load(object sender, EventArgs e)
    {
        tlist1.Add(new test1() {code="001", name="张三" });
        tlist1.Add(new test1() { code = "002", name = "李四" });
        tlist1.Add(new test1() { code = "003", name = "王五" });

        tlist2.Add(new test1() { code = "001", name = "张三" });
        tlist2.Add(new test1() { code = "004", name = "李四" });
        tlist2.Add(new test1() { code = "005", name = "王五" });

        tlist3.Add(new test1() { code = "001", name = "张三" });
        tlist3.Add(new test1() { code = "006", name = "李四" });
        tlist3.Add(new test1() { code = "003", name = "王五" });

        List<test1> ttlist = tlist1.Intersect(tlist2).Intersect(tlist3).ToList();
    }
}

public class test1
{
    public string code { get; set; }
    public string name { get; set; }
}

查看全文

相关阅读:
LeetCode 453 Minimum Moves to Equal Array Elements
LeetCode 112 Path Sum
LeetCode 437 Path Sum III
LeetCode 263 Ugly Number
Solutions and Summay for Linked List Naive and Easy Questions
AWS–Sysops notes
Linked List
All About Linked List
datatable fix error–Invalid JSON response
[转]反编译c#的相关问题

原文地址：https://www.cnblogs.com/zhengqian/p/6935015.html

2017-6-2 Linq 高级查询 （分页和组合查）、集合取交集

2017-6-2 Linq 高级查询（分页和组合查）、集合取交集