//Dictionary  
System.Collections.DictionaryEntry dic=new System.Collections.DictionaryEntry("key1","value1");  
 
Dictionary<int, string> fruit = new Dictionary<int, string>();  
 
//加入重复键会引发异常  
fruit.Add(1, "苹果");  
fruit.Add(2, "桔子");  
fruit.Add(3, "香蕉");  
fruit.Add(4, "菠萝");  
 
//因为引入了泛型，所以键取出后不需要进行Object到int的转换，值的集合也一样  
foreach (int i in fruit.Keys)  
{  
Console.WriteLine("键是：{0} 值是：{1}",i,fruit);  
}  
//删除指定键，值  
fruit.Remove(1);  
//判断是否包含指定键  
if (fruit.ContainsKey(1))  
{  
Console.WriteLine("包含此键");  
}  
//清除集合中所有对象  
fruit.Clear();  
}