Dictionary 字典

  使用简介：

   必须包含名空间System.Collection.Generic ;
    Dictionary里面的每一个元素都是一个键值对(由二个元素组成：键和值) 
    键必须是唯一的,而值不需要唯一的 
    键和值都可以是任何类型(比如：string, int, 自定义类型，等等) 

    在删除添加时，不会像列表一样，移动之后的所有元素，产生内存的开销。

 //定义
 Dictionary<string, string> openWith = new Dictionary<string, string>();

 //添加元素
    openWith.Add("txt", "notepad.exe");
    openWith.Add("bmp", "paint.exe");
    openWith.Add("dib", "paint.exe");
    openWith.Add("rtf", "wordpad.exe");

  //取值
    Console.WriteLine("For key = "rtf", value = {0}.", openWith["rtf"]);

  //更改值
    openWith["rtf"] = "winword.exe";
    Console.WriteLine("For key = "rtf", value = {0}.", openWith["rtf"]);

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

  //遍历value
    foreach (string value in openWith.Values)
    {
        Console.WriteLine("value = {0}", value);
    }

//遍历value, 第二种方法
    Dictionary<string, string>.ValueCollection valueColl = openWith.Values;
    foreach (string s in valueColl)
    {
        Console.WriteLine("Second Method, Value = {0}", s);
    }

   //遍历字典
    foreach (KeyValuePair<string, string> kvp in openWith)
    {
        Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
    }


 //添加存在的元素
    try
    {
        openWith.Add("txt", "winword.exe");
    }
    catch (ArgumentException)
    {
        Console.WriteLine("An element with Key = "txt" already exists.");
    }

   //删除元素
    openWith.Remove("doc");
    if (!openWith.ContainsKey("doc"))
    {
        Console.WriteLine("Key "doc" is not found.");
    }

 //判断键存在
    if (openWith.ContainsKey("bmp")) // True 
    {
        Console.WriteLine("An element with Key = "bmp" exists.");
    }

 //参数为其它类型 
    Dictionary<int, string[]> OtherType = new Dictionary<int, string[]>();
    OtherType.Add(1, "1,11,111".Split(','));
    OtherType.Add(2, "2,22,222".Split(','));
    Console.WriteLine(OtherType[1][2]);

参数为类

class DouCube
    {
        public int Code { get { return _Code; } set { _Code = value; } } private int _Code;
        public string Page { get { return _Page; } set { _Page = value; } } private string _Page;
    } 

 //声明并添加元素
    Dictionary<int, DouCube> MyType = new Dictionary<int, DouCube>();
    for (int i = 1; i <= 9; i++)
    {
        DouCube element = new DouCube();
        element.Code = i * 100;
        element.Page = "http://www.doucube.com/" + i.ToString() + ".html";
        MyType.Add(i, element);
    }

 //遍历元素
    foreach (KeyValuePair<int, DouCube> kvp in MyType)
    {
        Console.WriteLine("Index {0} Code:{1} Page:{2}", kvp.Key, kvp.Value.Code, kvp.Value.Page);
    } 

转：http://www.cnblogs.com/txw1958/archive/2012/11/07/csharp-dictionary.html