using System;

using System.Collections;

class Program

{

    static void Main(string[] args)

    {

        TestIEnumerable test = new TestIEnumerable();

        foreach (string str in test)

        {

            Console.WriteLine(str);

        }

        Console.ReadKey();

    }

}

class TestIEnumerable : IEnumerable

{

    private string[] _item;

    public TestIEnumerable()

    {

        _item = new string[]

             {

                 "","","",""

             };

    }

    public string this[int index]

    {

        get { return _item[index]; }

    }

    public IEnumerator GetEnumerator()

    {

        return new EnumeratorActualize(this);

    }

    class EnumeratorActualize : IEnumerator

    {

        private int index;

        private TestIEnumerable _testEnumerable;

        private object currentObj;

        public EnumeratorActualize(TestIEnumerable testEnumerable)

        {

            _testEnumerable = testEnumerable;

            currentObj = new object();

            index = -;

        }

        public object Current

        {

            get

            {

                return currentObj;

            }

        }

        public bool MoveNext()

        {

            if (index < _testEnumerable._item.Length - )

            {

                index++;

                currentObj = _testEnumerable._item[index];

                return true;

            }

            index = _testEnumerable._item.Length;

            return false;

        }

        public void Reset()

        {

            index = -;

        }

    }

}

using System;

using System.Collections;

public class MyClass: IDisposable

{

    public MyClass()

    {

        Console.WriteLine("constructor");

    }

    ~MyClass()

    {

        Console.WriteLine("destructor");

    }

    public void Dispose()

    {

        Console.WriteLine("implementation of IDisposable.Dispose()");

    }

}

public class MainClass

{

    static void Main()

    {

        using (MyClass MyObject = new MyClass())

        //using 关键字用于创建一个对象MyObject 该对象属于MyClass类

        //当代吗分支到达using代码的闭花括号时，将自动撤销该对象

        {

        }

    }

}

using System;

public enum LegalDoorStates

{

    DoorStateOpen,

    DoorStateClosed

}

class DoorController

{

    private LegalDoorStates CurrentState;

    public LegalDoorStates State

    {

        get

        {

            return CurrentState;

        }

        set

        {

            CurrentState = value;

        }

    }

}

class MainClass

{

    public static void Main()

    {

        DoorController Door;

        string EnumName;

        Door = new DoorController();

        Door.State = LegalDoorStates.DoorStateOpen;

       // EnumName = LegalDoorStates.GetName(typeof(LegalDoorStates), Door.State);

        EnumName = LegalDoorStates.Format(typeof(LegalDoorStates),1,"f");//g,x,d,f

        Console.WriteLine(EnumName);

    }

}

using System;

public class MainClass

{

    public enum Color

    {

    Red = 0,

        Orange,

        Yellow,

        Green,

        Blue,

        Indigo,

        Violet

    }

    static void Main()

    {

        Color MyColor;

        MyColor = Color.Green;

        Console.WriteLine("{0}", MyColor.CompareTo(Color.Red));

        Console.WriteLine("{0}", MyColor.CompareTo(Color.Green));

        Console.WriteLine("{0}", MyColor.CompareTo(Color.Violet));//CompareTo方法 比较

        Array ValueArray;

        ValueArray = Color.GetValues(typeof(Color));//GetValue方法返回一个包含所有枚举值的数组

        foreach (Color ColorItem in ValueArray)

            Console.WriteLine(ColorItem.ToString());

    }

}