C#基础知识（以宝马，车，车轮为例）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using ClassLibrary1.util;
using ClassLibrary1.util.util2;namespace ClassLibrary1
{//声明代理类public delegate void MyEvent();public class Class1{//enum是C#的关键字，定义枚举类型， Enum 是C#的一个类enum color:int {red=1, blue=2, white=3, gray=4, yellow=5};static void Main(string[] args){//ReadOrWriteFile();//BaseTest();//TestEnum();//ExceptionDeal();//varStringIsNull();// DeleGateTest();Class1 c = new Class1();c.TestEvent();Console.ReadKey();}/// <summary>/// 类，抽象类以及接口/// </summary>private static void varStringIsNull(){//String s = "";//bool b = StringUtil.IsNullOrEmpty(s);//Console.WriteLine(b);//Cars mycar = new Cars();//mycar.Name1 = "BMW";//mycar.Number1 = "888888";//Console.WriteLine("我是{0}，牌号为{1}.", mycar.Name1, mycar.Number1);//基类和派生类//Bmw bmw = new Bmw();//bmw.Name1 = "BMW";//bmw.Number1 = "888888";//Console.WriteLine("我是{0}，牌号为{1}.", bmw.Name1, bmw.Number1);//bmw.Country = "Germany";//Console.WriteLine("生产地：{0}", bmw.Country);//Console.WriteLine(bmw.getReturnValue());//抽象类 和 接口Bmw bmw = new Bmw();bmw.Name1 = "BMW";bmw.Number1 = "888888";Console.WriteLine("我是{0}，牌号为{1}.", bmw.Name1, bmw.Number1);bmw.Country = "Germany";bmw.Count = 4;Console.WriteLine("生产地：{0}", bmw.Country);Console.WriteLine(bmw.getReturnValue());Console.WriteLine("轮子数目：{0}", bmw.getWheelCount());bmw.createCar();bmw.useCar();bmw.destroyCar();}/// <summary>/// 声明一个委托类/// </summary>public delegate void MyDel(String msg);/// <summary>/// 声明调用委托/// </summary>/// <param name="msg"></param>public static void DelMessage(String msg){Console.WriteLine(msg);}/// <summary>/// 委托测试方法/// </summary>public static void DeleGateTest(){MyDel del = DelMessage;del("I am a delegate.");}public event MyEvent DelEvent;//定义事件，绑定代理/// <summary>/// 事件触发方法/// </summary>public virtual void FireEvent(){if (DelEvent != null){DelEvent();}}/// <summary>/// 事件测试方法/// </summary>public  void TestEvent(){DelEvent += new MyEvent(Test2Event);//注册FireEvent();//触发事件
        }/// <summary>/// 事件处理函数/// </summary>public void Test2Event(){Console.WriteLine("事件处理");}/// <summary>/// 捕获异常/// </summary>private static void ExceptionDeal(){int x = 1;int y = 0;try{int a = x / y;}catch (Exception e){Console.WriteLine(e.ToString());}}/// <summary>/// 枚举类型/// </summary>private static void TestEnum(){Console.WriteLine(color.blue);color c = color.red;switch (c){case color.blue: Console.WriteLine(color.blue); break;case color.gray: Console.WriteLine(color.gray); break;default: Console.WriteLine("other"); break;}String[] s = { "a", "b" };foreach (String e in s){Console.WriteLine(e);}}/// <summary>/// 基础测试/// </summary>private static void BaseTest(){//float f = 12.23F;//long  a = 1266666777777777863L;//String str = @"D:\files\temp\a.txt\t";//逐字符串：按原样输出//String str1 = "D:\files\temp\a.txt\t";//String str2 = @"""";//String str3 = """";编译时报错//Console.WriteLine(f);//Console.WriteLine(a);//Console.WriteLine("\v");//Console.WriteLine(str);//Console.WriteLine(str1);//Console.WriteLine(str2);//Console.WriteLine(str3);//String str = "XiaoLi";//Console.WriteLine("My name is {0}, how are you?", str);//字符串格式化， 参数化//字符串比较,可以直接用==号,也可以用Equals//String s1 = "hello,world";//String s2 = "hello,world";//if (s1 == s2)//{//    Console.WriteLine("相等");//}//if (s1.Equals(s2))//{//    Console.WriteLine("相等");//}//else//{//    Console.WriteLine("不相等");//}//值比较， 也可判断是否指向同一对象//String s1 = "hello,world";//String s2 = "hello,wor2ld";//if (s1.CompareTo(s2) <= 0)//{//    Console.WriteLine("指向同一对象");//}//else//{//    Console.WriteLine("不是指向同一对象");//}
}/// <summary>/// 读写文件/// </summary>private static void ReadOrWriteFile(){//@string path = @"e:\MyTest.txt";// Delete the file if it exists.if (File.Exists(path)){File.Delete(path);}//Create the file.//using using (FileStream fs = File.Create(path)){AddText(fs, "This is some text");AddText(fs, "This is some more text,");AddText(fs, "\r\nand this is on a new line");AddText(fs, "\r\n\r\nThe following is a subset of characters:\r\n");for (int i = 1; i < 120; i++){AddText(fs, Convert.ToChar(i).ToString());//Split the output at every 10th character.if (Math.IEEERemainder(Convert.ToDouble(i), 10) == 0){AddText(fs, "\r\n");}}}//Open the stream and read it back.using (FileStream fs = File.OpenRead(path)){byte[] b = new byte[1024];UTF8Encoding temp = new UTF8Encoding(true);while (fs.Read(b, 0, b.Length) > 0){Console.WriteLine(temp.GetString(b));}}}/// <summary>/// 写文件/// </summary>/// <param name="fs"></param>/// <param name="value"></param>private static void AddText(FileStream fs, string value){byte[] info = new UTF8Encoding(true).GetBytes(value);fs.Write(info, 0, info.Length);}}
}

using System;
using System.Collections.Generic;
using System.Linq;


namespace ClassLibrary1.util
{
    class StringUtil
    {
        public static bool IsNullOrEmpty(String str)
        {
            if (str == null || "".Equals(str)) return true;
            return false;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ClassLibrary1.util.util2;

namespace ClassLibrary1.util.util2
{
    class Cars:Wheels
    {
        private String Name;

        public String Name1
        {
            get { return Name; }
            set { Name = value; }
        }
        private String Number;

        public String Number1
        {
            get { return Number; }
            set { Number = value; }
        }
        public Cars()
        {
            Console.WriteLine("调用基类构造方法:{0}", DateTime.Now);
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ClassLibrary1.util.util2;

namespace ClassLibrary1.util.util2
{
    class Bmw:Cars,MyObjects
    {
        private String country;

        public String Country
        {
            get { return country; }
            set { country = value; }
        }
        public Bmw()
        {
            Console.WriteLine("调用派生类构造方法:{0}", DateTime.Now);
        }
        public  String getReturnValue()
        {
            return Name1 + Number1;
        
        }

        #region MyObjects 成员

        public void createCar()
        {
            Console.WriteLine("创建车。");
        }

        public void useCar()
        {
            Console.WriteLine("车使用中...");
        }

        public void destroyCar()
        {
            Console.WriteLine("销毁车。");
        }

        #endregion
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ClassLibrary1.util.util2
{
    interface MyObjects
    {
         void createCar();
         void useCar();
         void destroyCar();

    }
}