将HashTable转换为C＃中的字典＃

Question

如何将HashTable转换为C＃中的字典？可能吗？例如，如果我有HashTable中的对象集合，并且如果我想将它转换为具有特定类型的对象的字典，那么该怎么做？

Answer 1

public static Dictionary<K,V> HashtableToDictionary<K,V> (Hashtable table) 
{ 
    return table 
    .Cast<DictionaryEntry>() 
    .ToDictionary (kvp => (K)kvp.Key, kvp => (V)kvp.Value); 
} 

Answer 2

var table = new Hashtable(); 

table.Add(1, "a"); 
table.Add(2, "b"); 
table.Add(3, "c"); 


var dict = table.Cast<DictionaryEntry>().ToDictionary(d => d.Key, d => d.Value); 

Answer 3

你也可以创建代理-J的回答是

Dictionary<KeyType, ItemType> d = new Dictionary<KeyType, ItemType>(); 
foreach (var key in hashtable.Keys) 
{ 
d.Add((KeyType)key, (ItemType)hashtable[key]); 
} 

Answer 4

Hashtable openWith = new Hashtable(); 
    Dictionary<string, string> dictionary = new Dictionary<string, string>(); 

    // Add some elements to the hash table. 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"); 

    foreach (string key in openWith.Keys) 
    { 
     dictionary.Add(key, openWith[key].ToString()); 
    } 

Answer 5

扩展方法版本的扩展方法：

using System.Collections; 
using System.Collections.Generic; 
using System.Linq; 

public static class Extensions { 

    public static Dictionary<K,V> ToDictionary<K,V> (this Hashtable table) 
    { 
     return table 
     .Cast<DictionaryEntry>() 
     .ToDictionary (kvp => (K)kvp.Key, kvp => (V)kvp.Value); 
    } 
}