实现 IEnumerator<T> GetEnumerator() 和 IEnumerator IEnumerable.GetEnumerator() 的动态生成类

using System;
using System.Collections;
using System.Collections.Generic;

public class DynamicEnumerator<T> : IEnumerator<T>, IEnumerator
{
    private List<T> collection;
    private int currentIndex;

    public DynamicEnumerator(List<T> collection)
    {
        this.collection = collection;
        currentIndex = -1;
    }

    public T Current
    {
        get
        {
            try
            {
                return collection[currentIndex];
            }
            catch (IndexOutOfRangeException)
            {
                throw new InvalidOperationException();
            }
        }
    }

    object IEnumerator.Current => Current;

    public bool MoveNext()
    {
        currentIndex++;
        return currentIndex < collection.Count;
    }

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

    public void Dispose()
    {
        // 清理资源
    }
}

public class DynamicEnumerable<T> : IEnumerable<T>, IEnumerable
{
    private List<T> collection;

    public DynamicEnumerable(List<T> collection)
    {
        this.collection = collection;
    }

    public IEnumerator<T> GetEnumerator()
    {
        return new DynamicEnumerator<T>(collection);
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}

public class Program
{
    public static void Main()
    {
        List<int> numbers = new List<int> { 1, 2, 3, 4, 5 };
        DynamicEnumerable<int> dynamicEnumerable = new DynamicEnumerable<int>(numbers);

        foreach (int number in dynamicEnumerable)
        {
            Console.WriteLine(number);
        }
    }
}