Dictionary<string, string> myDic = new Dictionary<string, string>();
myDic.Add("aaa", "111");
myDic.Add("bbb", "222");
myDic.Add("ccc", "333");
myDic.Add("ddd", "444");
//如果添加已經(jīng)存在的鍵，add方法會拋出異常
try
{
 myDic.Add("ddd","ddd");
}
catch (ArgumentException ex)
{
 Console.WriteLine("此鍵已經(jīng)存在：" + ex.Message);
}
//解決add()異常的方法是用ContainsKey()方法來判斷鍵是否存在
if (!myDic.ContainsKey("ddd"))
{
 myDic.Add("ddd", "ddd");
}
else
{
 Console.WriteLine("此鍵已經(jīng)存在：");
 
}
 
//而使用索引器來負值時，如果建已經(jīng)存在，就會修改已有的鍵的鍵值，而不會拋出異常
myDic ["ddd"]="ddd";
myDic["eee"] = "555";
 
//使用索引器來取值時，如果鍵不存在就會引發(fā)異常
try
{
 Console.WriteLine("不存在的鍵""fff""的鍵值為：" + myDic["fff"]);
}
catch (KeyNotFoundException ex)
{
 Console.WriteLine("沒有找到鍵引發(fā)異常：" + ex.Message);
}
//解決上面的異常的方法是使用ContarnsKey() 來判斷時候存在鍵，如果經(jīng)常要取健值得化最好用 TryGetValue方法來獲取集合中的對應鍵值
string value = "";
if (myDic.TryGetValue("fff", out value))
{
 Console.WriteLine("不存在的鍵""fff""的鍵值為：" + value );
}
else
{
 Console.WriteLine("沒有找到對應鍵的鍵值");
}
 
//下面用foreach 來遍歷鍵值對
//泛型結構體 用來存儲健值對
foreach (KeyValuePair<string, string> kvp in myDic)
{
 Console.WriteLine("key={0},value={1}", kvp.Key, kvp.Value);
}
//獲取值得集合
foreach (string s in myDic.Values)
{
 Console.WriteLine("value={0}", s);
}
//獲取值得另一種方式
Dictionary<string, string>.ValueCollection values = myDic.Values;
foreach (string s in values)
{
 Console.WriteLine("value={0}", s);
}

<?xml version="1.0" encoding="UTF-8"?>
<data>
 <resource key="123">foo</resource>
 <resource key="456">bar</resource>
 <resource key="789">bar</resource>
</data>
i want to put this into a Dictionary (sorted) as key value pairs. i.e: 123:foo, 456:bar...etc
the keys are unknown.
 
string s = "<data><resource key=/"123/">foo</resource><resource key=/"456/">bar</resource><resource key=/"789/">bar</resource></data>";
 XmlDocument xml = new XmlDocument();
 xml.LoadXml(s);
 XmlNodeList resources = xml.SelectNodes("data/resource");
 SortedDictionary<string,string> dictionary = new SortedDictionary<string,string>();
 foreach (XmlNode node in resources){
 dictionary.Add(node.Attributes["key"].Value, node.InnerText);
 }

linq to xml:
var xml = XDocument.Load(...);
var sequence = from e in xml.Root.Elements() 
let key = (string)e.Attribute("key")
order by key
select new { 
 Key = key, 
 Value = (string)e 
};

希望本文所述對大家的C#程序設計有所幫助。