将List <KeyValuePair <string,string >>序列化为JSON

Question

我是JSON的新手,请帮忙!

我试图将a序列List<KeyValuePair<string, string>>化为JSON

目前:

[{"Key":"MyKey 1","Value":"MyValue 1"},{"Key":"MyKey 2","Value":"MyValue 2"}]

预期:

[{"MyKey 1":"MyValue 1"},{"MyKey 2":"MyValue 2"}]

我提到了这个和这个的一些例子.

这是我的KeyValuePairJsonConverter:JsonConverter

public class KeyValuePairJsonConverter : JsonConverter
{
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        List<KeyValuePair<object, object>> list = value as List<KeyValuePair<object, object>>;
        writer.WriteStartArray();
        foreach (var item in list)
        {
            writer.WriteStartObject();
            writer.WritePropertyName(item.Key.ToString());
            writer.WriteValue(item.Value.ToString());
            writer.WriteEndObject();
        }
        writer.WriteEndArray();
    }

    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(List<KeyValuePair<object, object>>);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        var jsonObject = JObject.Load(reader);
        var target = Create(objectType, jsonObject);
        serializer.Populate(jsonObject.CreateReader(), target);
        return target;
    }

    private object Create(Type objectType, JObject jsonObject)
    {
        if (FieldExists("Key", jsonObject))
        {
            return jsonObject["Key"].ToString();
        }

        if (FieldExists("Value", jsonObject))
        {
            return jsonObject["Value"].ToString();
        }
        return null;
    }

    private bool FieldExists(string fieldName, JObject jsonObject)
    {
        return jsonObject[fieldName] != null;
    }
}

我是从这样的WebService方法调用它

List<KeyValuePair<string, string>> valuesList = new List<KeyValuePair<string, string>>();
Dictionary<string, string> valuesDict = SomeDictionaryMethod();

foreach(KeyValuePair<string, string> keyValue in valuesDict)
{
    valuesList.Add(keyValue);
}

JsonSerializerSettings jsonSettings = new JsonSerializerSettings { Converters = new [] {new KeyValuePairJsonConverter()} };
string valuesJson = JsonConvert.SerializeObject(valuesList, jsonSettings);

Answer 1

您可以使用Newtonsoft和字典:

    var dict = new Dictionary<int, string>();
    dict.Add(1, "one");
    dict.Add(2, "two");

    var output = Newtonsoft.Json.JsonConvert.SerializeObject(dict);

输出是:

{"1":"one","2":"two"}

编辑

感谢 @Sergey Berezovskiy提供的信息.

您目前正在使用Newtonsoft,因此只需将您更改List<KeyValuePair<object, object>>为Dictionary<object,object>并使用包中的serialize和deserialize方法.

Answer 2

所以我不想使用除本机 c# 之外的任何东西来解决类似的问题，作为参考，这是使用 .net 4、jquery 3.2.1 和主干 1.2.0。

我的问题是List<KeyValuePair<...>>控制器会处理到主干模型中，但是当我保存该模型时，控制器无法绑定列表。

public class SomeModel {
    List<KeyValuePair<int, String>> SomeList { get; set; }
}

[HttpGet]
SomeControllerMethod() {
    SomeModel someModel = new SomeModel();
    someModel.SomeList = GetListSortedAlphabetically();
    return this.Json(someModel, JsonBehavior.AllowGet);
}

网络捕获：

"SomeList":[{"Key":13,"Value":"aaab"},{"Key":248,"Value":"aaac"}]

但是，即使在支持 model.js 中正确设置 SomeList 尝试保存模型而不对其进行任何更改，也会导致绑定 SomeModel 对象与请求正文中的参数具有相同的长度，但所有键和值都为空：

[HttpPut]
SomeControllerMethod([FromBody] SomeModel){
    SomeModel.SomeList; // Count = 2, all keys and values null.
}

我唯一能找到的是 KeyValuePair 是一个结构，而不是可以以这种方式实例化的东西。我最终做的是以下内容：

• 在包含键、值字段的某处添加一个模型包装器：

  public class KeyValuePairWrapper {
      public int Key { get; set; }
      public String Value { get; set; }
  
      //default constructor will be required for binding, the Web.MVC binder will invoke this and set the Key and Value accordingly.
      public KeyValuePairWrapper() { }
  
      //a convenience method which allows you to set the values while sorting
      public KeyValuePairWrapper(int key, String value)
      {
          Key = key;
          Value = value;
      }
  }
  

• 设置您的绑定类模型以接受您的自定义包装器对象。

  public class SomeModel
  {
      public List<KeyValuePairWrapper> KeyValuePairList{ get; set }; 
  }
  

• 从控制器中获取一些 json 数据

  [HttpGet]
  SomeControllerMethod() {
      SomeModel someModel = new SomeModel();
      someModel.KeyValuePairList = GetListSortedAlphabetically();
      return this.Json(someModel, JsonBehavior.AllowGet);
  }
  

• 稍后做一些事情，也许调用了model.save(null, ...)

  [HttpPut]
  SomeControllerMethod([FromBody] SomeModel){
      SomeModel.KeyValuePairList ; // Count = 2, all keys and values are correct.
  }