C# 迭代器模式

public class Swimers : IEnumerable
{
    // Methods
    public IEnumerator GetEnumerator()
    {
        Program.Swimers iteratorVariable0 = new Program.Swimers {
            Name = "LBJ"
        };
        yield return iteratorVariable0;
        Program.Swimers iteratorVariable1 = new Program.Swimers {
            Name = "KB"
        };
        yield return iteratorVariable1;
        Program.Swimers iteratorVariable2 = new Program.Swimers {
            Name = "KB1"
        };
        yield return iteratorVariable2;
        Program.Swimers iteratorVariable3 = new Program.Swimers {
            Name = "KB1"
        };
        yield return iteratorVariable3;
    }

    public override string ToString()
    {
        return ("Name:" + this.Name);
    }

    // Properties
    public int Age { get; set; }

    public string Club { get; set; }

    public string Name { get; set; }

    // Nested Types
    [CompilerGenerated]
    private sealed class <GetEnumerator>d__4 : IEnumerator<object>, IEnumerator, IDisposable
    {
        // Fields
        private int <>1__state;
        private object <>2__current;
        public Program.Swimers <>4__this;
        public Program.Swimers <>g__initLocal0;
        public Program.Swimers <>g__initLocal1;
        public Program.Swimers <>g__initLocal2;
        public Program.Swimers <>g__initLocal3;

        // Methods
        [DebuggerHidden]
        public <GetEnumerator>d__4(int <>1__state)
        {
            this.<>1__state = <>1__state;
        }

        private bool MoveNext()
        {
            switch (this.<>1__state)
            {
                case 0:
                    this.<>1__state = -1;
                    this.<>g__initLocal0 = new Program.Swimers();
                    this.<>g__initLocal0.Name = "LBJ";
                    this.<>2__current = this.<>g__initLocal0;
                    this.<>1__state = 1;
                    return true;

                case 1:
                    this.<>1__state = -1;
                    this.<>g__initLocal1 = new Program.Swimers();
                    this.<>g__initLocal1.Name = "KB";
                    this.<>2__current = this.<>g__initLocal1;
                    this.<>1__state = 2;
                    return true;

                case 2:
                    this.<>1__state = -1;
                    this.<>g__initLocal2 = new Program.Swimers();
                    this.<>g__initLocal2.Name = "KB1";
                    this.<>2__current = this.<>g__initLocal2;
                    this.<>1__state = 3;
                    return true;

                case 3:
                    this.<>1__state = -1;
                    this.<>g__initLocal3 = new Program.Swimers();
                    this.<>g__initLocal3.Name = "KB1";
                    this.<>2__current = this.<>g__initLocal3;
                    this.<>1__state = 4;
                    return true;

                case 4:
                    this.<>1__state = -1;
                    break;
            }
            return false;
        }

        [DebuggerHidden]
        void IEnumerator.Reset()
        {
            throw new NotSupportedException();
        }

        void IDisposable.Dispose()
        {
        }

        // Properties
        object IEnumerator<object>.Current
        {
            [DebuggerHidden]
            get
            {
                return this.<>2__current;
            }
        }

        object IEnumerator.Current
        {
            [DebuggerHidden]
            get
            {
                return this.<>2__current;
            }
        }
    }
}

C# 迭代器：

1. 实现了IEnumerate 获知 IEnumerate<T> 就能使用。foreach.

2. 编译器自动生成了迭代器的代码。

3. yield return用来向迭代器增加对象。

4. 注意Dispose()

 refer this passage:

http://csharpindepth.com/Articles/Chapter6/IteratorBlockImplementation.aspx