LINQ初学1.1--Where

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
{
    protected void Page_Load(object sender, EventArgs e)
    {
        
       // Server.Transfer("Default2.aspx");
         #region 根据条件查询数组
        Response.Write("<hr>列出数组中字符长度大于等于6的字符串数组：<br>");
        string[] Demo1 = { "Ajax", "Csharp", "Javascript", "Css Desige", "Asp.net", "Gis" };
        var books = from n in Demo1 
                    where n.Length >= 6 
                    select n;

        foreach (var book in books){
            Response.Write(string.Format("<span class='result'>{0}</span>",book));
        }
        #endregion

        #region where查询的Lambda表达式
        Response.Write("<hr>where查询的快捷方法：<br>");
        var books2 = Demo1.Where(book => book.Length >= 6);

        foreach (var book in books2)
        {
            Response.Write(string.Format("<span class='result'>{0}</span>", book));
        }
        #endregion
        
        #region 根据条件查询集合体

        Response.Write("<hr>列出集合中语言为Chinese的学生：<br>");
        List<Student> Demo2 = GetStudents();
        var students1 = from n in Demo2
                        where n.Language == "Chinese"
                        select n.Name;

        foreach (var student in students1){
            Response.Write(string.Format("<span class='result'>{0}</span>", student));
        }
        #endregion

        #region 根据条件查询集合体
        Response.Write("<hr>列出集合中名字里包含“B”的学生姓名和语言：<br>");
        var student2 = from n in Demo2
                       where n.Name.IndexOf("B") > -1
                       select n;
        foreach (var student in student2)
        {
            Response.Write("<span class='result'>"+student.Name+"   "+student.Language+"</span><br />");
        }
       #endregion
          

        #region 根据条件查询集合体
        Response.Write("<hr>列出集合中年龄大于等于20的英国或苏格兰学生：<br>");
        var students2 = from n in Demo2
                        where (n.Language == "English" || n.Language == "Scotland") && n.Age >= 20
                        select n;

        foreach (var student in students2){
            Response.Write(string.Format("<span class='result'>{0}</span>", student.Name));
        }
        #endregion
    }

    #region 构造一个学生集合体
    private List<Student> GetStudents()
    {
        List<Student> students = new List<Student> { 
             new Student{ Name="YOUNG", Age=25, Language="Chinese"},
             new Student{ Name="JESSIE", Age=21, Language="Scotland"},
             new Student{ Name="KELLY", Age=18, Language="English"},
             new Student{ Name="JUNE", Age=20, Language="English"},
             new Student{ Name="ADRIAN", Age=22, Language="Italy"},
             new Student{ Name="BRUCE", Age=17, Language="Scotland"},
             new Student{ Name="BRANT", Age=30, Language="Germany"},
             new Student{ Name="BEN", Age=25, Language="Chinese"}
        };
        return students;
    }
    #endregion


    #region 学生类
    class Student
    {
        public int Age { get; set; }
        public string Name { get; set; }
        public string Language { get; set; }
    }
    #endregion


}

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