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  • KeyValuePair VS DictionaryEntry

    There are some difference between KeyValuePair which is the generic version and DictionaryEntry which is non generic version. 

    1. KeyValuePair < T,T > is for iterating through Dictionary < T,T >. This is the .Net 2 way of doing things.
    2. DictionaryEntry is for iterating through HashTables. This is the .Net 1 way of doing things.
    3. KeyValuePair<TKey,TValue> is used in place of DictionaryEntry because it is generic.
    The advantage of using a KeyValuePair<TKey,TValue> is that we can give the compiler more information about what is in our dictionary. Esp. the data type
    Dictionary<string, int> dict = new Dictionary<string, int>();
    foreach (KeyValuePair<string, int> item in dict) {
      int i = item.Value;
    }
    
    Hashtable hashtable = new Hashtable();
    foreach (DictionaryEntry item in hashtable) {
      // Cast required because compiler doesn't know it's a <string, int> pair.
      int i = (int) item.Value;
    }
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  • 原文地址:https://www.cnblogs.com/dennysong/p/5621277.html
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