Question

假设我有以下词典：

private Dictionary<int, string> dic1 = new Dictionary<int, string>()
{
      { 1, "a" },
      { 2, "b" },
      { 3, "c" }
}

private Dictionary<SomeEnum, bool> dic2 = new Dictionary<SomeEnum, bool>()
{
      { SomeEnum.First, true },
      { SomeEnum.Second, false },
      { SomeEnum.Third, false }
}

我想将这两个词典转换为Dictionary<string, object>

例如：

 dic1 = new Dictionary<string, object>()
 {
     { "1", "a" },
     { "2", "b" },
     { "3", "c" }
 }

 dic2 = new Dictionary<string, object>()
 {
     { "First", true },
     { "Second", false },
     { "Third", false }
 }

正如您所看到的，这些词典的string键只是之前词典的string表示。

负责转换的方法具有以下签名：

 public static object MapToValidType(Type type, object value)
 {
     //....

     if(typeof(IDictionary).IsAssignableFrom(type))
     {
         //I have to return a Dictionary<string, object> here
         return ??;
     }
 }

我尝试了以下内容：

 ((IDictionary)value).Cast<object>().ToDictionary(i => ...);

但是i被转换为一个对象，所以我无法访问键或值项。为此，我需要将其投放到合适的KeyValuePair<TKey, TValue>，但我不知道TKey或TValue类型。

另一种解决方案是：

IDictionary dic = (IDictionary)value;
IList<string> keys = dic.Keys.Cast<object>().Select(k => Convert.ToString(k)).ToList();
IList<object> values = dic.Values.Cast<object>().ToList();
Dictionary<string, object> newDic = new Dictionary<string, object>();
for(int i = 0; i < keys.Count; i++)
   newDic.Add(keys[0], values[0]);
return newDic;

但是，我并不喜欢这种方法，我真的在寻找一个更简单，更友好的单行LINQ语句。

Answer 1

    static void Main(string[] args)
    {
        var blah = KeyToString(dic1);

        // Verify that we converted correctly
        foreach (var kvp in blah)
        {
            Console.WriteLine("{0} {1}, {2} {3}", kvp.Key.GetType(), kvp.Key, kvp.Value.GetType(), kvp.Value);
        }
    }

    static Dictionary<string, TValue> KeyToString<TKey, TValue>(IEnumerable<KeyValuePair<TKey, TValue>> dic1)
    {
        return dic1.ToDictionary(kvp => kvp.Key.ToString(), kvp => kvp.Value);
    }

Answer 2

你可以试试这个，不过LINQ，我觉得你不需要：

x.h

或者是Linq：

 Dictionary<string, object> ConvertToDictionary(System.Collections.IDictionary iDic) {
            var dic = new Dictionary<string, object>();
            var enumerator = iDic.GetEnumerator();
            while (enumerator.MoveNext()) {
                dic[enumerator.Key.ToString()] = enumerator.Value;
            }
        return dic;
    }

Answer 3

public static IDictionary<string, object> Convert<TKey, TValue>(IDictionary<TKey, TValue> genDictionary)
{
    return genDictionary.Select(kvp => new KeyValuePair<string, object>(kvp.Key.ToString(), (object)kvp.Value)).ToDictionary(x => x.Key, x => x.Value);
}

调用如：

    var dicIntInt = new Dictionary<int, string>{{123, "asdc"}, {456, "aa"} };

    Dictionary<string, object> dicStrObj = Convert(dicIntInt);

https://dotnetfiddle.net/eY41MQ

Answer 4

诀窍是将您的IDictionary转换为通用类型的DictionaryEntry。然后，您可以使用System.Linq中的ToDictionary（）。

static Dictionary<string,object> ToDictionary(IDictionary dic)
{
    return dic.Cast<DictionaryEntry> ().ToDictionary ((t) => t.Key.ToString (), (t) => t.Value);
}

IDictionary上的LINQ操作

4 个答案: