C# System.Collections.Generic.Dictionary

 using System;
 using System.Collections.Generic;

 public class Example
 {
     public static void Main()
     {
         // Create a new dictionary of strings, with string keys.
         //
         Dictionary<string, string> openWith =
             new Dictionary<string, string>();

         // Add some elements to the dictionary. There are no
         // duplicate keys, but some of the values are duplicates.
         openWith.Add("txt", "notepad.exe");
         openWith.Add("bmp", "paint.exe");
         openWith.Add("dib", "paint.exe");
         openWith.Add("rtf", "wordpad.exe");

         // The Add method throws an exception if the new key is
         // already in the dictionary.
         try
         {
             openWith.Add("txt", "winword.exe");
         }
         catch (ArgumentException)
         {
             Console.WriteLine("An element with Key = \"txt\" already exists.");
         }

         // The Item property is another name for the indexer, so you
         // can omit its name when accessing elements.
         Console.WriteLine("For key = \"rtf\", value = {0}.",
             openWith["rtf"]);

         // The indexer can be used to change the value associated
         // with a key.
         openWith["rtf"] = "winword.exe";
         Console.WriteLine("For key = \"rtf\", value = {0}.",
             openWith["rtf"]);

         // If a key does not exist, setting the indexer for that key
         // adds a new key/value pair.
         openWith["doc"] = "winword.exe";

         // The indexer throws an exception if the requested key is
         // not in the dictionary.
         try
         {
             Console.WriteLine("For key = \"tif\", value = {0}.",
                 openWith["tif"]);
         }
         catch (KeyNotFoundException)
         {
             Console.WriteLine("Key = \"tif\" is not found.");
         }

         // When a program often has to try keys that turn out not to
         // be in the dictionary, TryGetValue can be a more efficient
         // way to retrieve values.
         string value = "";
         if (openWith.TryGetValue("tif", out value))
         {
             Console.WriteLine("For key = \"tif\", value = {0}.", value);
         }
         else
         {
             Console.WriteLine("Key = \"tif\" is not found.");
         }

         // ContainsKey can be used to test keys before inserting
         // them.
         if (!openWith.ContainsKey("ht"))
         {
             openWith.Add("ht", "hypertrm.exe");
             Console.WriteLine("Value added for key = \"ht\": {0}",
                 openWith["ht"]);
         }

         // When you use foreach to enumerate dictionary elements,
         // the elements are retrieved as KeyValuePair objects.
         Console.WriteLine();
         foreach( KeyValuePair<string, string> kvp in openWith )
         {
             Console.WriteLine("Key = {0}, Value = {1}",
                 kvp.Key, kvp.Value);
         }

         // To get the values alone, use the Values property.
         Dictionary<string, string>.ValueCollection valueColl =
             openWith.Values;

         // The elements of the ValueCollection are strongly typed
         // with the type that was specified for dictionary values.
         Console.WriteLine();
         foreach( string s in valueColl )
         {
             Console.WriteLine("Value = {0}", s);
         }

         // To get the keys alone, use the Keys property.
         Dictionary<string, string>.KeyCollection keyColl =
             openWith.Keys;

         // The elements of the KeyCollection are strongly typed
         // with the type that was specified for dictionary keys.
         Console.WriteLine();
         foreach( string s in keyColl )
         {
             Console.WriteLine("Key = {0}", s);
         }

         // Use the Remove method to remove a key/value pair.
         Console.WriteLine("\nRemove(\"doc\")");
         openWith.Remove("doc");

         if (!openWith.ContainsKey("doc"))
         {
             Console.WriteLine("Key \"doc\" is not found.");
         }
     }
 }

 /* This code example produces the following output:

 An element with Key = "txt" already exists.
 For key = "rtf", value = wordpad.exe.
 For key = "rtf", value = winword.exe.
 Key = "tif" is not found.
 Key = "tif" is not found.
 Value added for key = "ht": hypertrm.exe

 Key = txt, Value = notepad.exe
 Key = bmp, Value = paint.exe
 Key = dib, Value = paint.exe
 Key = rtf, Value = winword.exe
 Key = doc, Value = winword.exe
 Key = ht, Value = hypertrm.exe

 Value = notepad.exe
 Value = paint.exe
 Value = paint.exe
 Value = winword.exe
 Value = winword.exe
 Value = hypertrm.exe

 Key = txt
 Key = bmp
 Key = dib
 Key = rtf
 Key = doc
 Key = ht

 Remove("doc")
 Key "doc" is not found.
  */

 using System;
 using System.Collections.Generic;
 public class Example
 {
          public static void Main()
          {
                //一、创建泛型哈希表，然后加入元素
                Dictionary<string, string> oscar = new Dictionary<string, string>();
                oscar.Add("哈莉?贝瑞", "《死囚之舞》");
                oscar.Add("朱迪?丹奇", "《携手人生》");
                oscar.Add("尼科尔?基德曼", "《红磨坊》");
                oscar.Add("詹妮弗?康纳利", "《美丽心灵》");
                oscar.Add("蕾妮?齐维格", "《BJ单身日记》");

                //二、删除元素
                oscar.Remove("詹妮弗?康纳利");

                //三、假如不存在元素则加入元素
                if (!oscar.ContainsKey("茜茜?斯派克")) oscar.Add("茜茜?斯派克", "《不伦之恋》");

                //四、显然容量和元素个数
                Console.WriteLine("元素个数: {0}", oscar.Count);

                //五、遍历集合
                Console.WriteLine("74届奥斯卡最佳女主角及其电影：");
                foreach (KeyValuePair<string, string> kvp in oscar)
                {
                       Console.WriteLine("姓名：{0},电影：{1}", kvp.Key, kvp.Value);
                }

               //六、得到哈希表中键的集合
               Dictionary<string, string>.KeyCollection keyColl = oscar.Keys;
               //遍历键的集合
               Console.WriteLine("最佳女主角：");
               foreach (string s in keyColl)
               {
                    Console.WriteLine(s);
               }

               //七、得到哈希表值的集合
               Dictionary<string, string>.ValueCollection valueColl = oscar.Values;
               //遍历值的集合
               Console.WriteLine("最佳女主角电影：");
               foreach (string s in valueColl)
               {
                    Console.WriteLine(s);
               }

               //八、使用TryGetValue方法获取指定键对应的值
               string slove = string.Empty;
               if (oscar.TryGetValue("朱迪?丹奇", out slove))
                      Console.WriteLine("我最喜欢朱迪?丹奇的电影{0}", slove);
               else
                      Console.WriteLine("没找到朱迪?丹奇的电影");

               //九、清空哈希表
               oscar.Clear();
               Console.ReadLine();
        }
 }

 //定义字典
                 Dictionary<string, string> d = new Dictionary<string, string>();

                 //添加字典的元素
                 for (int i = ; i < ; i++)
                 {
                     d.Add("key" + i, "value" + i);
                 }

                 //取值/赋值
                 string val = d["key1"];
                 d["key1"] = "new value";

                 //遍历key
                 foreach (string key in d.Keys)
                 {
                     Console.WriteLine("Key = {0}", key);
                 }
                 //遍历value
                 foreach (string v in d.Values)
                 {
                     Console.WriteLine("value = {0}", v);
                 }

                 //遍历value, Second Method
                 Dictionary<string, string>.ValueCollection valueColl = d.Values;
                 foreach (string s in valueColl)
                 {
                     Console.WriteLine("Second Method, Value = {0}", s);
                 }

                 //遍历字典
                 foreach (KeyValuePair<string, string> kvp in d)
                 {
                     Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
                 }
                 //删除元素
                 d.Remove("key1");
                 if (!d.ContainsKey("key1"))
                 {
                     Console.WriteLine("Key \"key1\" is not found.");
                 }
                 //判断键存在
                 if (d.ContainsKey("key1")) // True
                 {
                     Console.WriteLine("An element with Key = \"key1\" exists.");
                 }

构造函数

Dictionary<TKey,TValue>()	初始化 Dictionary<TKey,TValue> 类的新实例，该实例为空且具有默认的初始容量，并使用键类型的默认相等比较器。
Dictionary<TKey,TValue>(IDictionary<TKey,TValue>)	初始化 Dictionary<TKey,TValue> 类的新实例，该实例包含从指定的 IDictionary<TKey,TValue> 中复制的元素并为键类型使用默认的相等比较器。
Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>)	初始化 Dictionary<TKey,TValue> 类的新实例，该实例包含从指定的 IDictionary<TKey,TValue> 中复制的元素并使用指定的 IEqualityComparer<T>。
Dictionary<TKey,TValue>(IEqualityComparer<TKey>)	初始化 Dictionary<TKey,TValue> 类的新实例，该实例为空且具有默认的初始容量，并使用指定的 IEqualityComparer<T>。
Dictionary<TKey,TValue>(Int32)	初始化 Dictionary<TKey,TValue> 类的新实例，该实例为空且具有指定的初始容量，并为键类型使用默认的相等比较器。
Dictionary<TKey,TValue>(Int32, IEqualityComparer<TKey>)	初始化 Dictionary<TKey,TValue> 类的新实例，该实例为空且具有指定的初始容量，并使用指定的 IEqualityComparer<T>。
Dictionary<TKey,TValue>(SerializationInfo, StreamingContext)	用序列化数据初始化 Dictionary<TKey,TValue> 类的新实例。

属性

Comparer	获取用于确定字典中的键是否相等的 IEqualityComparer<T>。
Count	获取包含在 Dictionary<TKey,TValue> 中的键/值对的数目。
Item[TKey]	获取或设置与指定的键关联的值。
Keys	获取包含 Dictionary<TKey,TValue> 中的键的集合。
Values	获取包含 Dictionary<TKey,TValue> 中的值的集合。

方法

Add(TKey, TValue)	将指定的键和值添加到字典中。
Clear()	将所有键和值从 Dictionary<TKey,TValue> 中移除。
ContainsKey(TKey)	确定是否 Dictionary<TKey,TValue> 包含指定键。
ContainsValue(TValue)	确定 Dictionary<TKey,TValue> 是否包含特定值。
Equals(Object)	确定指定的对象是否等于当前对象。 (Inherited from Object)
GetEnumerator()	返回循环访问 Dictionary<TKey,TValue> 的枚举数。
GetHashCode()	作为默认哈希函数。 (Inherited from Object)
GetObjectData(SerializationInfo, StreamingContext)	实现 ISerializable 接口，并返回序列化 Dictionary<TKey,TValue> 实例所需的数据。
GetType()	获取当前实例的 Type。 (Inherited from Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (Inherited from Object)
OnDeserialization(Object)	实现 ISerializable 接口，并在完成反序列化之后引发反序列化事件。
Remove(TKey)	从 Dictionary<TKey,TValue> 中移除所指定的键的值。
ToString()	返回表示当前对象的字符串。 (Inherited from Object)
TryGetValue(TKey, TValue)	获取与指定键关联的值。