#有个水果篮里面最多可以装10个苹果和香蕉，她们都派生自一个叫水果的基类。使用接口IEnumerable和IEnumerator实现装入水果及遍历水果的过程

好的，下面是一个使用C#语言实现的示例，展示了如何使用`IEnumerable`和`IEnumerator`接口来装入水果及遍历水果的过程。 首先，我们定义一个水果基类： ```csharp public class Fruit { public string Name { get; set; } public Fruit(string name) { Name = name; } } ``` 接下来，我们定义苹果和香蕉类，它们都继承自水果基类： ```csharp public class Apple : Fruit { public Apple(string name) : base(name) { } } public class Banana : Fruit { public Banana(string name) : base(name) { } } ``` 然后，我们定义一个水果篮类，该类实现了`IEnumerable`接口： ```csharp using System; using System.Collections; using System.Collections.Generic; public class FruitBasket : IEnumerable<Fruit> { private List<Fruit> fruits; private int capacity; public FruitBasket(int capacity) { this.capacity = capacity; fruits = new List<Fruit>(capacity); } public void Add(Fruit fruit) { if (fruits.Count < capacity) { fruits.Add(fruit); } else { Console.WriteLine("水果篮已满，无法添加更多水果。"); } } public IEnumerator<Fruit> GetEnumerator() { return new FruitBasketEnumerator(fruits); } IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); } private class FruitBasketEnumerator : IEnumerator<Fruit> { private List<Fruit> fruits; private int currentIndex; public FruitBasketEnumerator(List<Fruit> fruits) { this.fruits = fruits; currentIndex = -1; } public Fruit Current { get { if (currentIndex == -1 || currentIndex >= fruits.Count) { throw new InvalidOperationException(); } return fruits[currentIndex]; } } object IEnumerator.Current => Current; public bool MoveNext() { if (currentIndex < fruits.Count - 1) { currentIndex++; return true; } return false; } public void Reset() { currentIndex = -1; } public void Dispose() { // No unmanaged resources to dispose } } } ``` 最后，我们编写一个测试程序来装入水果并遍历水果： ```csharp public class Program { public static void Main() { FruitBasket basket = new FruitBasket(10); basket.Add(new Apple("苹果1")); basket.Add(new Banana("香蕉1")); basket.Add(new Apple("苹果2")); basket.Add(new Banana("香蕉2")); foreach (var fruit in basket) { Console.WriteLine(fruit.Name); } } } ``` 运行上述程序，你会看到水果篮中的水果被遍历并打印出来。