本文实例讲述了C#实现自定义Dictionary类。分享给大家供大家参考。具体如下：
1.关于MyDictionary类
本文中实现的MyDictionary类具有如下功能
1）可以增加、修改、删除键值对
2）可以通过索引器，找到一个键对应的值
3）可以遍历打印类中全部的键值对
4）可以将类中的序列转化为有序的（不排序、升序、降序）List类型
MyDictionary类是一个具有两个参数的泛型类，内部机制采用以键值对（KeyValuePair）类型为元素的双向链表（LinkedList）实现
2.实现代码
class MyDictioinary<TKey, TValue> { LinkedList<KeyValuePair<TKey, TValue>> llDictionary = new LinkedList<KeyValuePair<TKey, TValue>>(); /// <summary> /// 索引器，输入TKey可以找到对应的TValue /// </summary> /// <param name="tk">键值</param> /// <returns></returns> public TValue this[TKey tk] { get { foreach(KeyValuePair<TKey, TValue> kvp in llDictionary) { if (tk.Equals(kvp.Key)) { return kvp.Value; } } return default(TValue); } } /// <summary> /// 添加一组数据 /// </summary> /// <param name="tk"></param> /// <param name="tv"></param> public void Add(TKey tk, TValue tv) { foreach (KeyValuePair<TKey, TValue> kvp in llDictionary) { if (tk.Equals(kvp.Key)) { throw new Exception("新增失败：主键已经存在"); } } llDictionary.AddLast(new KeyValuePair<TKey, TValue>(tk, tv)); } /// <summary> /// 删除一组数据 /// </summary> /// <param name="tk"></param> public void Delete(TKey tk) { foreach (KeyValuePair<TKey, TValue> kvp in llDictionary) { if (tk.Equals(kvp.Key)) { llDictionary.Remove(kvp); return; } } throw new Exception("删除失败：不存在这个主键"); } /// <summary> /// 修改一组数据 /// </summary> /// <param name="tk"></param> /// <param name="tv"></param> public void Modify(TKey tk, TValue tv) { LinkedListNode<KeyValuePair<TKey, TValue>> lln = llDictionary.First; while (lln != null ) { if (tk.Equals(lln.Value.Key)) { llDictionary.AddBefore(lln, new KeyValuePair<TKey, TValue>(tk, tv)); llDictionary.Remove(lln); return; } lln = lln.Next; } throw new Exception("修改失败：不存在这个主键"); } /// <summary> /// 打印整个Dictionary内的全部数据 /// </summary> public void PrintData() { Console.WriteLine("=================="); Console.WriteLine("输出数据"); Console.WriteLine("=================="); foreach (KeyValuePair<TKey, TValue> kvp in llDictionary) { Console.WriteLine(kvp.Key.ToString() + "t:" + kvp.Value.ToString()); } Console.WriteLine(string.Format("共计输出 {0} 项", llDictionary.Count)); Console.WriteLine(DateTime.Now.ToLongTimeString()); Console.WriteLine("=================="); } /// <summary> /// 决定按什么顺序打印Dictionary内的数据 /// </summary> public enum PrintType { Normal = 0, //不排序 Ascend = 1, //升序排列 Descend = 2 //降序佩列 }; /// <summary> /// 返回List类型的数据 /// </summary> /// <param name="printType">List内数据的排序情况</param> /// <returns></returns> public List<KeyValuePair<TKey, TValue>> ToList(PrintType printType = PrintType.Normal) { switch (printType) { case PrintType.Normal: { return llDictionary.ToList(); } case PrintType.Ascend: { if (llDictionary.Count == 0) return null; LinkedList<KeyValuePair<TKey, TValue>> newll = new LinkedList<KeyValuePair<TKey, TValue>>(); try { LinkedListNode<KeyValuePair<TKey, TValue>> lln = llDictionary.First; while (lln != null) { LinkedListNode<KeyValuePair<TKey, TValue>> lln2 = newll.First; while (lln2 != null) { //Key是字符串的情况 if (llDictionary.First.Value.Key.GetType() == "string".GetType()) { if (string.Compare(lln2.Value.Key.ToString(), lln.Value.Key.ToString()) > 0) { newll.AddBefore(lln2, new LinkedListNode <KeyValuePair<TKey, TValue>>(lln.Value)); break; } } else //Key可以被转化为浮点数的情况 { if (double.Parse(lln2.Value.Key.ToString()) > double.Parse(lln.Value.Key.ToString())) { newll.AddBefore(lln2, new LinkedListNode <KeyValuePair<TKey, TValue>>(lln.Value)); break; } } lln2 = lln2.Next; } if (lln2 == null) { newll.AddLast(new LinkedListNode <KeyValuePair<TKey, TValue>>(lln.Value)); } lln = lln.Next; } } catch (Exception ex) { Console.WriteLine(ex.Message); } return newll.ToList(); } case PrintType.Descend: { if (llDictionary.Count == 0) return null; LinkedList<KeyValuePair<TKey, TValue>> newll = new LinkedList<KeyValuePair<TKey, TValue>>(); try { LinkedListNode<KeyValuePair<TKey, TValue>> lln = llDictionary.First; while (lln != null) { LinkedListNode<KeyValuePair<TKey, TValue>> lln2 = newll.First; while (lln2 != null) { //Key是字符串的情况 if (llDictionary.First.Value.Key.GetType() == "string".GetType()) { if (string.Compare(lln2.Value.Key.ToString(), lln.Value.Key.ToString()) < 0) { newll.AddBefore(lln2, new LinkedListNode <KeyValuePair<TKey, TValue>>(lln.Value)); break; } } else //Key可以被转化为浮点数的情况 { if (double.Parse(lln2.Value.Key.ToString()) < double.Parse(lln.Value.Key.ToString())) { newll.AddBefore(lln2, new LinkedListNode <KeyValuePair<TKey, TValue>>(lln.Value)); break; } } lln2 = lln2.Next; } if (lln2 == null) { newll.AddLast(new LinkedListNode <KeyValuePair<TKey, TValue>>(lln.Value)); } lln = lln.Next; } } catch (Exception ex) { Console.WriteLine(ex.Message); } return newll.ToList(); } default: return null; } } }
3.Main函数调用示例
static void Main(string[] args) { MyDictioinary<string, string> dic = new MyDictioinary<string, string>(); //插入两组数据 dic.Add("1", "MERCURY"); dic.Add("2", "VENUS"); //尝试插入重复主键的数据 报警：主键不存在 try { dic.Add("1", "EARTH"); } catch (Exception ex) { Console.WriteLine(ex.Message); } //删除一组数据 dic.Delete("1"); //添加一组数据 dic.Add("1", "MARS"); //修改两组数据 dic.Modify("1", "JUPITER"); dic.Modify("2", "SATURN"); //添加两组数据 dic.Add("6", "SUN"); dic.Add("5", "MOON"); dic.Add("8", "URANUS"); dic.Add("9", "NEPTUNE"); dic.PrintData(); //通过索引找到对应值 Console.WriteLine("key为6的元素value为：" + dic["6"]); Console.WriteLine("key为3的元素value为：" + dic["3"]); List<KeyValuePair<string, string>> l; //输出升序排列好的List l = dic.ToList(MyDictioinary<string, string>.PrintType.Ascend); Console.WriteLine("升序排列后的List："); for (int i = 0; i < l.Count; i++) { Console.WriteLine(l[i].Key.ToString() + "t:" + l[i].Value.ToString()); } //输出降序排列好的List l = dic.ToList(MyDictioinary<string, string>.PrintType.Descend); Console.WriteLine("降排列后的List："); for (int i = 0; i < l.Count; i++) { Console.WriteLine(l[i].Key.ToString() + "t:" + l[i].Value.ToString()); } Console.ReadLine(); }
4.运行示例
希望本文所述对大家的C#程序设计有所帮助。
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