C# 中实现 foreach 功能

1. MySplit 类

    /// <summary>
    /// MySplit 类
    /// </summary>
    public class MySplit : IEnumerable
    {
        private string[] elements;

        public MySplit(string source, char[] delimiters)
        {
            elements = source.Split(delimiters);
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return new MyEnumerator(this);
        }

        #region 在嵌套类中实现 IEnumerator 接口
        /// <summary>
        /// 在嵌套类中实现 IEnumerator 接口，以便以后方便创建多个枚举
        /// </summary>
        public class MyEnumerator : IEnumerator
        {
            private int position = -1;
            private MySplit t;

            public MyEnumerator(MySplit t)
            {
                this.t = t;
            }

            public bool MoveNext()
            {
                if (position < t.elements.Length - 1)
                {
                    position++;
                    return true;
                }
                else
                {
                    return false;
                }
            }

            public void Reset()
            {
                position = -1;
            }

            object IEnumerator.Current
            {
                get
                {
                    try
                    {
                        return t.elements[position];
                    }
                    catch (IndexOutOfRangeException)
                    {
                        throw new InvalidOperationException();
                    }
                }
            }
        }
        #endregion
    }

2. 使用

    MySplit mySplit = new MySplit("大豆男生: I Love You!", new char[] { ' ', '-' });
    foreach (string item in mySplit)
    {
        Console.WriteLine(item);
    }

3. 输出结果
   大豆男生:
   I
   Love
   You!

相关文章：C# 中实现索引指示器

本文地址：http://www.cnblogs.com/anjou/archive/2007/07/05/807357.html