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();

    }
}