在c＃中迭代JSON对象数组名称值对 [英] Iterating a JSON object array name value pair in c#

问题描述

我在这里提到了一个类似的问题：

I've taken this example from a similar question here:

在C＃中迭代JSON对象（不是数组）

但是我的数据格式有些不同，它有数组括号。

But my data format is a little different, it has array brackets.

正如我所指出的那样，我可以有一个未定义的条目数量，根据定义的类将数据结构提取为数组/对象列表。

As pointed out I can have an undefined number of entries, I want to walk through the entries and extract the data structure into an array/list of objects based on the class defined.

{
  "-KeArK3V02mXYWx2OMWh" : [{
    "Description" : "this is a description",
    "Location" : "Atlanta",
    "Name" : "Event One",
    "Time" : "2017-03-01T21:53:12.924645Z"
  }],
  "-KeAtCNF_rmewZ_U3PpH" : [{
    "Description" : "another description",
    "Location" : "Charlotte",
    "Name" : "Event Two",
    "Time" : "2017-03-01T22:01:25.603547Z"
  }],
  "-KeAtd8CQW_EfH3Sw4YQ" : [{
    "Description" : "description goes here",
    "Location" : "Toronto",
    "Name" : "Event Three",
    "Time" : "2017-03-01T22:03:19.3953859Z"
  }]
}

我有一个名为Event的类，定义如下

and I have a class called Event that is defined as follows

class Title {
  public string Description { get; set; }
  public string Location { get; set; }
  public string Name { get; set; }
  public DateTime Time { get; set; }
}

给我的答案（我认为是正确的）不工作

The answer given there (which I thought was correct) isn't working

Dictionary<string, Title> elist = JsonConvert.DeserializeObject<Dictionary<string, Title>>(jsonString);

它给我一个错误：

无法将当前JSON数组（例如[1,2,3]）反序列化为标题类型，因为该类型需要一个JSON对象（例如{name：value}）来正确反序列化。
要解决此错误，请将JSON更改为JSON对象（例如{name：value}），或将反序列化类型更改为实现集合接口的数组或类型（例如ICollection，IList）像可以从JSON数组反序列化的List。 JsonArrayAttribute也可以添加到类型，以强制它从JSON数组反序列化。
路径'-KeArK3V02mXYWx2OMWh'，第2行，位置XX。

Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'Title' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly. To fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List that can be deserialized from a JSON array. JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array. Path '-KeArK3V02mXYWx2OMWh', line 2, position XX.

推荐答案

是Json的结构问题。你的json格式与Key和value一样，但是值是根据json格式的数组。你必须做以下事情。

There is a problem with structure of Json. Your json has format like Key and value but value is array as per json format. You have to do following thing.

Dictionary<string,Title[]> elist = JsonConvert.DeserializeObject<Dictionary<string, Title[]>>(jsonString);

以上解决方案是最简单的。

Above solution is simplest one.

第二个解决方案。 （您必须根据需要进行修改，但目前的json将会工作）

Second solution. ( You have to modify as your need but current json will work)

 public class TitleConverter : JsonConverter
    {
        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            JArray jObject = JArray.Load(reader);

            Title title = JsonConvert.DeserializeObject<Title>(jObject[0].ToString());
                return title;
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }

        public override bool CanConvert(Type objectType)
        {
            if (objectType.Name == "Title")
                return true;
            return false;
        }
    }

现在使用这样。

Dictionary<string,Title> elist = JsonConvert.DeserializeObject<Dictionary<string, Title>>(jsonString,new TitleConverter());

这篇关于在c＃中迭代JSON对象数组名称值对的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！