使用JavaScriptSerializer序列化字典

Question

顯然，IDictionary<string,object>被序列化爲KeyValuePair對象的數組（例如，[{Key:"foo", Value:"bar"}, ...]）。是否可以將其序列化爲對象（例如，{foo:"bar"}）？

Answer 1

雖然我同意JavaScriptSerializer是廢話，Json.Net是一個更好的選擇，您可以使JavaScriptSerializer以您想要的方式序列化。 你將不得不註冊一個轉換器，並使用這樣的重寫Serialize方法：

public class KeyValuePairJsonConverter : JavaScriptConverter 
{ 
    public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer) 
    { 
     var instance = Activator.CreateInstance(type); 

     foreach (var p in instance.GetType().GetPublicProperties()) 
     { 
      instance.GetType().GetProperty(p.Name).SetValue(instance, dictionary[p.Name], null); 
      dictionary.Remove(p.Name); 
     } 

     foreach (var item in dictionary) 
      (instance).Add(item.Key, item.Value); 

     return instance; 
    } 
    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer) 
    { 
     var result = new Dictionary<string, object>(); 
     var dictionary = obj as IDictionary<string, object>; 
     foreach (var item in dictionary) 
      result.Add(item.Key, item.Value); 
     return result; 
    } 
    public override IEnumerable<Type> SupportedTypes 
    { 
     get 
     { 
      return new ReadOnlyCollection<Type>(new Type[] { typeof(your_type) }); 
     } 
    } 
} 

JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer(); 
javaScriptSerializer.RegisterConverters(new JavaScriptConverter[] { new ExpandoJsonConverter() }); 
jsonOfTest = javaScriptSerializer.Serialize(test); 
// {"x":"xvalue","y":"\/Date(1314108923000)\/"} 

希望這有助於！

Answer 2

不，這不可能與JavaScriptSerializer。這是可能的Json.NET：

public class Bar 
{ 
    public Bar() 
    { 
     Foos = new Dictionary<string, string> 
     { 
      { "foo", "bar" } 
     }; 
    } 

    public Dictionary<string, string> Foos { get; set; } 
} 

然後：

var bar = new Bar(); 
string json = JsonConvert.SerializeObject(bar, new KeyValuePairConverter()); 

產生所需：

{"Foos":{"foo":"bar"}} 

Answer 3

我能夠使用JavaScriptSerializer解決它，訣竅是創建自己的轉換器。下面的代碼工作代碼：

public class KeyValuePairJsonConverter : JavaScriptConverter { 
    public override object Deserialize(IDictionary<string, object> dictionary 
             , Type type 
             , JavaScriptSerializer serializer) { 
     throw new InvalidOperationException("Sorry, I do serializations only."); 
    } 

    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer) { 
     Dictionary<string, object> result = new Dictionary<string, object>(); 
     Dictionary<string, MyClass> dictionaryInput = obj as Dictionary<string, MyClass>; 

     if (dictionaryInput == null) { 
      throw new InvalidOperationException("Object must be of Dictionary<string, MyClass> type."); 
     } 

     foreach (KeyValuePair<string, MyClass> pair in dictionaryInput) 
      result.Add(pair.Key, pair.Value); 

     return result; 
    } 

    public override IEnumerable<Type> SupportedTypes { 
     get { 
      return new ReadOnlyCollection<Type>(new Type[] { typeof(Dictionary<string, MyClass>) }); 
     } 
    } 
} 

這裏是你如何使用它：

JavaScriptSerializer js = new JavaScriptSerializer(); 
js.RegisterConverters(new JavaScriptConverter[] { new KeyValuePairJsonConverter() }); 
Context.Response.Clear(); 
Context.Response.ContentType = "application/json"; 
Context.Response.Write(js.Serialize(myObject)); 

Answer 4

這裏有一個我相信從托馬斯的回答改進版本。奇蹟般有效。我們也可以爲ScriptIgnore屬性添加一個檢查，但是也可以自己敲一下。

順便說一下，我選擇了JavaScriptSerializer，因爲在我看來，第三方解決方案大部分時間都是這樣：不太知道，安裝時間長，經常被遺忘的先決條件和模糊的版權狀態，這使得它們在商業中分發風險更大。

P-S：我沒有理解爲什麼我們試圖將實例和實例反序列化爲字典，所以我剝去了這部分。

public class KeyValuePairJsonConverter : JavaScriptConverter 
{ 
    public override object Deserialize(IDictionary<string, object> deserializedJSObjectDictionary, Type targetType, JavaScriptSerializer javaScriptSerializer) 
    { 
     Object targetTypeInstance = Activator.CreateInstance(targetType); 

     FieldInfo[] targetTypeFields = targetType.GetFields(BindingFlags.Public | BindingFlags.Instance); 

     foreach (FieldInfo fieldInfo in targetTypeFields) 
      fieldInfo.SetValue(targetTypeInstance, deserializedJSObjectDictionary[fieldInfo.Name]); 

     return targetTypeInstance; 
    } 

    public override IDictionary<string, object> Serialize(Object objectToSerialize, JavaScriptSerializer javaScriptSerializer) 
    { 
     IDictionary<string, object> serializedObjectDictionary = new Dictionary<string, object>(); 

     FieldInfo[] objectToSerializeTypeFields = objectToSerialize.GetType().GetFields(BindingFlags.Public | BindingFlags.Instance); 

     foreach (FieldInfo fieldInfo in objectToSerializeTypeFields) 
      serializedObjectDictionary.Add(fieldInfo.Name, fieldInfo.GetValue(objectToSerialize)); 

     return serializedObjectDictionary; 
    } 

    public override IEnumerable<Type> SupportedTypes 
    { 
     get 
     { 
      return new ReadOnlyCollection<Type>(new Type[] { typeof(YOURCLASSNAME) }); 
     } 
    } 
} 

Answer 5

我能夠解決JavaScriptSerializer LINQ的選擇：

var dictionary = new Dictionary<int, string>(); 
var jsonOutput = new JavaScriptSerializer().Serialize(dictionary.Select(x => new { Id = x.Key, DisplayText = x.Value }));