01.C#核心语法

class A
{
    private int[] array = new int[20];
    public int this[int index]//索引器
    {
        get
        { return array[index]; }
        set
        { array[index] = value; }
    }
}
class Program
{
    static void Main(string[] args)
    {
        A a = new A();
        a[0] = 1;//访问索引器set
        a[19] = 2;//访问索引器set
        Console.WriteLine(a[0] + " " + a[19]);//访问索引器get
    }
}

class A
{
    private Hashtable m_map = new Hashtable();
    public string this[string key]//索引器
    {
        get
        { return m_map[key].ToString(); }
        set
        { m_map[key] = value; }
    }
    public string this[int key]//重载索引器
    {
        get
        { return m_map[key].ToString(); }
        set
        { m_map[key] = value; }
    }
}
class Program
{
    static void Main(string[] args)
    {
        A a = new A();
        a["001"] = "lizhiwei";
        a[2] = "li";
        Console.WriteLine(a["001"] + " " + a[2]);
    }
}

class A
{
    private string m_name;
    private int m_age;
    private string m_sex;
    public string Name
    {
        get
        { return m_name; }
        set
        { m_name = value; }
    }
    public int Age
    {
        get
        { return m_age; }
        set
        { m_age = value; }
    }
    public string Sex
    {
        get
        { return m_sex; }
        set
        { m_sex = value; }
    }
}
class B
{
    private ArrayList m_list = new ArrayList();
    public int this[string name, string sex]
    {
        get
        {
            foreach (A a in m_list)
            {
                if (a.Name.Equals(name) && a.Sex.Equals(sex))
                {
                    return a.Age;
                }
            }
            return -1;
        }
        set
        {
            A a = new A();
            a.Name = name;
            a.Sex = sex;
            a.Age = value;//value的类型与返回值类型一致(这里是int)
            m_list.Add(a);
        }
    }
}
class Program
{
    static void Main(string[] args)
    {
        B b = new B();
        b["李志伟", "男"] = 20;
        b["张三", "男"] = 10;
        Console.Write(b["李志伟", "男"] + " " + b["张三", "男"]);
    }
}

delegate void PrintDelegate(string s);//申明委托
class A
{
    public void Print(string s)//与委托的返回值、参数相同的函数
    {
        Console.WriteLine(s);
    }
}
class Program
{
    static void Main(string[] args)
    {
        A a = new A();
        PrintDelegate s = new PrintDelegate(a.Print);//新建委托链
        s("李志伟");//执行委托连
    }
}

delegate void PrintDelegate(string s);//申明委托
class A
{
    private string name;
    public A(string name)
    {
        this.name = name;
    }
    public void Print(string s)//与委托的返回值、参数相同的函数
    {
        Console.Write(name + s + " ");
    }
}
class Program
{
    static void Main(string[] args)
    {
        A a1 = new A("a1");
        A a2 = new A("a2");
        PrintDelegate s = new PrintDelegate(a1.Print);//新建委托链
        s += new PrintDelegate(a2.Print);//增加委托链
        s += new PrintDelegate(a2.Print);//增加委托链
        s("李志伟");//执行委托链
        Console.WriteLine();
        s -= new PrintDelegate(a2.Print);//减少委托链
        s("李志伟");//执行委托链
    }
}

delegate void PrintDelegate(string s);//申明委托
class Program
{
    static void Main(string[] args)
    {
        PrintDelegate s = null;
        s += delegate(string temp) { Console.WriteLine(temp); };//委托指向匿名方法
        s("李志伟");//执行委托连
    }
}

class Program
{
    private void Hello(string name)//无返回值
    {
        Console.WriteLine("你好，" + name + "!");
    }
    private string GETAge(int age)//有返回值
    {
        Console.WriteLine("我的年龄：" + age + "!");
        return "我的年龄：" + age + "!";
    }
    static void Main(string[] args)
    {
        Program p = new Program();
        Action<string> action = p.Hello;
        //Action<string> hello = new Action<string>(p.Hello);
        action("李志伟");//执行委托
        Func<int, string> fun = p.GETAge;
        Console.WriteLine(fun(20));//执行委托
    }
}

class Program
{
    static void Main(string[] args)
    {
        //标准的Lambda格式
        Func<int, int, string> sum = (int a, int b) => { return "和是：" + (a + b); };
        Console.WriteLine(sum(5, 6));//和是：11
        //简写格式
        Action<string> action = param => Console.WriteLine(param);//委托匿名方法
        action("调用委托");
        Func<int, Double> func = param => param * param;//有返回值的匿名方法
        Console.WriteLine(func(5));//25，调用委托返回25
    }
}

12.事件(event)

class A
    { 
        public delegate void Publish();//事件方法的委托
        public event Publish OnPublish;//事件委托链
        public void OnEvent()//触发事件，执行事件委托链
        {
            if (OnPublish != null)//事件委托链不为null
            {
                Console.WriteLine("事件被触发，执行事件委托链!");
                OnPublish();//执行事件委托链
            }
        }
        public void Event()//触发事件执行的方法
        {
            Console.WriteLine("执行触发事件执行的方法!");
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            A a = new A();
            a.OnPublish += new A.Publish(a.Event);//订阅(注册)事件，本质是增加委托链
            a.OnPublish += new A.Publish(a.Event);//订阅(注册)事件，本质是增加委托链
            a.OnEvent();//触发事件，执行事件委托链
        }
    }

//包含事件数据的类，命名方式:EventNameEventArgs
class AEventArgs : EventArgs
{
    private readonly string name;//只读属性
    public AEventArgs(string name)
    {
        this.name = name;
    }
    public string Name
    {
        get
        { return name; }
    }
}
//引发事件的类
class B
{
    //事件方法的委托，命名方式EventNameEventHandler
    public delegate void PublishEventHandler(object sender, AEventArgs e);
    //事件委托链
    public event PublishEventHandler Publish;
    //引发执行事件委托链的方法，命名方式:OnEventName
    protected virtual void OnEvent(AEventArgs e)
    {
        PublishEventHandler handler = Publish;
        if (handler != null)
        {
            handler(this, e);
        }
    }
    //触发事件的方法
    public void TriggerEvent(string name)
    {
        Console.WriteLine("事件被触发！！！");
        //调用引发执行事件委托链的方法
        OnEvent(new AEventArgs(name));
    }
    //事件处理的方法
    public void HandlingEvents(object sender, AEventArgs e)
    {
        Console.WriteLine(e.Name + " 处理事件！！！");
    }
}
class Program
{
    static void Main(string[] args)
    {
        B b = new B();
        //订阅(注册)事件，本质是增加委托链
        b.Publish += new B.PublishEventHandler(b.HandlingEvents);
        b.TriggerEvent("李志伟");
    }
}

interface IA
{
    void print();//抽象方法，不能使用public等修饰符
    string Name//抽象属性，也可使用抽象索引器
    {
        set;
        get;
    }
}
class B : IA
{
    private string m_name;
    public void print()//不能使用override或new
    {
        Console.WriteLine(m_name);
    }
    public string Name//不能使用override或new
    {
        set { m_name = value; }
        get { return m_name; }
    }
}
class Program
{
    static void Main(string[] args)
    {
        B b = new B();
        b.Name = "李志伟";
        b.print();
    }
}

interface IA
{
    void print();
}
interface IB
{
    void print();
}
class A : IA, IB
{
    void IA.print()//显示接口成员实现，不能使用public等关键字,只能是private
    {
        Console.WriteLine("IA.print");
    }
    void IB.print()//显示接口成员实现，不能使用public等关键字,只能是private
    {
        Console.WriteLine("IB.print");
    }
    public void print()
    {
        Console.WriteLine("A.print");
    }
}
class Program
{
    static void Main(string[] args)
    {
        A a = new A();
        ((IA)a).print();//使用IA接口访问，IA的print()
        ((IB)a).print();//使用IB接口访问，IB的print()
        a.print();//只能访问自己的print()
    }
}

interface IA
{
    void F();
}
interface IB : IA
{
    new void F();//隐藏了IA的F()
}
interface IC : IA
{
    void G();
}
interface IBC : IB, IC
{
}
class Test : IBC
{
    public void F()
    {
        Console.WriteLine("IB.F");//由于IB隐藏了IA的F(),所以这里实现的是IB的F()
    }
    public void G()
    {
        Console.WriteLine("IC.G");
    }
}
class Program
{
    static void Main(string[] args)
    {
        Test t = new Test();
        t.F();
        ((IA)t).F();
        ((IB)t).F();
        ((IC)t).F();//值得注意，由于IB隐藏了IA的F(),所以这里调用的是IB的F()
        ((IBC)t).F();
    }
}

interface IA
{
    void print();
}
class A : IA
{
    void IA.print()//接口的继承
    {
        Console.WriteLine("A.print");
    }
}
class B : A, IA
{
    public void print()//接口的重新实现，将会覆盖接口的继承，所以A的print()被完全覆盖
    {
        Console.WriteLine("B.print");
    }
}
class Program
{
    static void Main(string[] args)
    {
        B b = new B();
        ((IA)b).print();
    }
}

class Program
{
    static void Main(string[] args)
    {
        int[] array = { 2, 3, 6, 9, 8, 4, 7, 5, 0 };
        Array.Sort(array);//排序方法
        foreach (int i in array)
        {
            Console.Write(i + " ");
        }
    }
}

class A : IComparable
{
    private string name;
    private int age;
    public A(string name, int age)
    {
        this.name = name;
        this.age = age;
    }
    public int CompareTo(object obj)//实现比较的方法
    {
        A temp;
        if (obj is A)
        {
            temp = obj as A;
        }
        else
        {
            throw new ArgumentException("类型不一致！");
        }
        return this.name.CompareTo(temp.name);//根据姓名排序
    }
    public override string ToString()
    {
        return "[" + name + " " + age + "]";
    }
}
class Program
{
    static void Main(string[] args)
    {
        A[] array = new A[3];
        array[0] = new A("李志伟", 20);
        array[1] = new A("张三", 19);
        array[2] = new A("李四", 17);
        Array.Sort(array);//排序方法，对自定义类型进行排序
        foreach (A i in array)
        {
            Console.Write(i + " ");
        }
    }
}

class A
{
    private string name;
    private int age;
    public A(string name, int age)
    {
        this.name = name;
        this.age = age;
    }
    public string Name
    {
        get { return name; }
    }
    public int Age
    {
        get { return age; }
    }
    public override string ToString()
    {
        return "[" + name + " " + age + "]";
    }
}
class B : IComparer//专为类A设计的排序类
{
    private static B b;
    private B()
    {
    }
    public static B GetB()
    {
        if (b == null)
        {
            b = new B();
        }
        return b;
    }
    public int Compare(Object x, Object y)//实现排序方法
    {
        A xa, ya;
        if ((x is A) && (y is A))
        {
            xa = x as A;
            ya = y as A;
        }
        else
        {
            throw new ArgumentException("类型不一致！");
        }
        return xa.Name.CompareTo(ya.Name);//根据姓名排序
    }
}
class Program
{
    static void Main(string[] args)
    {
        A[] array = new A[3];
        array[0] = new A("李志伟", 20);
        array[1] = new A("张三", 19);
        array[2] = new A("李四", 17);
        Array.Sort(array, B.GetB());//排序方法
        foreach (A i in array)
        {
            Console.Write(i + " ");
        }
    }
}

17.扩展方法

public static class MyExtensions//静态的扩展类
{
    public static int StringExtensions(this String str)//为String类增加一个方法
    {
        Console.WriteLine(str);
        return str.Length;
    }
    public static String StringJoin(this String str1, String str2)//为String类增加一个方法
    {
        Console.WriteLine(str1 + str2);
        return str1 + str2;
    }
}
class Program
{
    static void Main(string[] args)
    {
        String s = "12345678";
        s.StringExtensions();//测试自定义的扩展方法
        s.StringJoin("000000000000000");//测试自定义的扩展方法
    }
}

18.密封类和密封方法(sealed)

19.yield return语句动态的返回集合

class Program
{
    static IEnumerable<string> GetEnumerator(int a, int b)
    {
        long d = 1;
        for (int i = 1; i <= b; i++)
        {
            d = a * d;
            yield return a + "的" + i + "次方是：" + d;//多次被执行
        }
    }
    static void Main(string[] args)
    {
        foreach (string s in GetEnumerator(2, 20))//遍历返回的集合
        {
            Console.WriteLine(s);
        }
    }
}

class Program
    {
        static void Main(string[] args)
        {
            for (int i = 0; i < 30; i++)
            {
                ThreadStart threadStart = new ThreadStart(Calculate);
                Thread thread = new Thread(threadStart);
                thread.Start();
            }
            Thread.Sleep(2000);
            Console.Read();
        }
        public static void Calculate()
        {
            DateTime time = DateTime.Now;//得到当前时间
            Random ra = new Random();//随机数对象
            Thread.Sleep(ra.Next(10,100));//随机休眠一段时间
            Console.WriteLine(time.Minute + ":" + time.Millisecond);
        }
}

class Program
{
    static void Main(string[] args)
    {
        for (int i = 0; i < 30; i++)
        {
            ParameterizedThreadStart tStart = new ParameterizedThreadStart(Calculate);
            Thread thread = new Thread(tStart);
            thread.Start(i * 10 + 10);//传递参数
        }
        Thread.Sleep(2000);
        Console.Read();
    }
    public static void Calculate(object arg)
    {
        Random ra = new Random();//随机数对象
        Thread.Sleep(ra.Next(10, 100));//随机休眠一段时间
        Console.WriteLine(arg);
    }
}