<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Index.aspx.cs" Inherits="WebApplication1.Index" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> </head> <body> <form id="form1" runat="server"> <div> <asp:Button ID="Button1" runat="server" Text="隐式类型局部变量" onclick="Button1_Click" /> <br /> <asp:Button ID="Button2" runat="server" onclick="Button2_Click" Text="自动属性" /> <br /> <asp:Button ID="Button3" runat="server" Text="对象初始化器" onclick="Button3_Click" /> <br /> <asp:Button ID="Button4" runat="server" Text="集合初始化器" onclick="Button4_Click" /> <br /> <asp:Button ID="Button5" runat="server" Text="匿名类型" onclick="Button5_Click" /> <br /> <asp:Button ID="Button6" runat="server" Text="扩展方法" onclick="Button6_Click" style="height: 21px" /> <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> <br /> <asp:Button ID="Button7" runat="server" Text="Lambda表达式" onclick="Button7_Click" /> </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; namespace WebApplication1 { //委托类型 public delegate int DelDemo(int a,int b); public partial class Index : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void Button1_Click(object sender, EventArgs e) { //隐式类别局部变量 //1.定义时必须给值 //2.定义时变量的类型会根据值自动识别,所以在重新赋值时给的值必须对应类型的值 //3.局部变量可以用它定义 var v = 10; var v2 = 12.5; //v = "abc";//错 int i; i = 10; //var v3;//错 //v3 = 20; } //自动属性 protected void Button2_Click(object sender, EventArgs e) { Student stu = new Student(); stu.Sex = "男"; stu.StuName = "张三"; stu.StuId = "12"; } //对象初始化 protected void Button3_Click(object sender, EventArgs e) { //可以少写构造函数， Student stu = new Student() { StuId="12" }; Student stu1 = new Student() { StuName = "李四", StuId = "13" }; Student stu2 = new Student() { Sex = "男" }; } //集合初始化器 protected void Button4_Click(object sender, EventArgs e) { int[] arr = { 10, 20, 30, 40 }; List<int> list = new List<int>() { 102, 221, 411, 225 }; Response.Write("长度:"+list.Count); //例定义一个list，默认存放三个学生 List<Student> list1 = new List<Student>() { new Student(){ StuId="1001",StuName="李四",Sex="男"}, new Student(){ StuId="1002",StuName="张三",Sex="女"}, new Student(){ StuId="1003", StuName="王五",Sex="男"} }; } //匿名类型 protected void Button5_Click(object sender, EventArgs e) { //直接创建分数对象 var g = new { Gid = "1001", Score = 89, StuId = "1001" };//编译器会为我们自动生成一个类,类中包函以上属性 Response.Write("分数:"+g.Score); } //扩展方法 protected void Button6_Click(object sender, EventArgs e) { string pwd = TextBox1.Text; string str = pwd.MD5(); string str1 = pwd.SHA1(); Response.Write("MD5加密后"+str); Response.Write("SHA1加密后" + str1); this.Alert("你好"); } public int Sum(int a, int b) { return a + b; } protected void Button7_Click(object sender, EventArgs e) { //Lambda表达本质上就是一个委托对象 DelDemo dd = new DelDemo(Sum);//委托的标准写法 //2.C#2.0中的匿名方法的写法 DelDemo dd2 = delegate(int a, int b) { return a - b; }; //3.C#3.0中退出的Lambda表达式的写法 DelDemo dd3 = (a, b) => a - b;//{int x=a-b}; //调用委托的方法 int i = dd3(10,20); Response.Write(i); //需要用Lambda表达式的扩展方法 List<int> list=new List<int>(){ 54,20,67,44,77,89}; int s = list.Sum(); Response.Write("所有人的成绩:"+s); //把及格人的总分算出来 //func<方法的参数类型,方法的返回值类型> Func<int, bool> f = (a) => a > 60; //where 查询符合委托条件的数，以集合返回 //IEnumerable是所有数组与集合父接口 IEnumerable<int> ds = list.Where(f); int d = ds.Sum(); Response.Write("结果:"+d); } } }
using System; using System.Collections.Generic; using System.Linq; using System.Web; namespace WebApplication1 { public class Student { string stuId; public string StuId { get { return stuId; } set { stuId = value; } } string stuName; public string StuName { get { return stuName; } set { stuName = value; } } //1.自动属性，在编译器编译时，会为这个属性生成一个变量 //get与set操作的是这个变量 //2.get与set必须都有 public string Sex{ get;set; } } }