反序列化不同类型的 JSON 数组

Question

我是 JSON.NET 新手，我需要帮助来反序列化以下 JSON

{
   "items": [
      [10, "file1", "command 1"],
      [20, "file2", "command 2"],
      [30, "file3", "command 3"]
   ]
}

对此

IList<Item> Items {get; set;}
class Item
{
   public int    Id      {get; set}
   public string File    {get; set}
   public string Command {get; set}
}

JSON 中的内容始终按相同的顺序排列。

Answer 1

您可以使用

自定义JsonConverter将 JSON 中的每个子数组转换为Item。 以下是转换器所需的代码：

class ItemConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return (objectType == typeof(Item));
    }
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JArray array = JArray.Load(reader);
        return new Item
        {
            Id = (int)array[0],
            File = (string)array[1],
            Command = (string)array[2]
        };
    }
    public override bool CanWrite
    {
        get { return false; }
    }
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

使用上面的转换器，您可以轻松地反序列化到您的类中，如下所示：

class Program
{
    static void Main(string[] args)
    {
        string json = @"
        {
           ""items"": [
              [10, ""file1"", ""command 1""],
              [20, ""file2"", ""command 2""],
              [30, ""file3"", ""command 3""]
           ]
        }";
        Foo foo = JsonConvert.DeserializeObject<Foo>(json, new ItemConverter());
        foreach (Item item in foo.Items)
        {
            Console.WriteLine("Id: " + item.Id);
            Console.WriteLine("File: " + item.File);
            Console.WriteLine("Command: " + item.Command);
            Console.WriteLine();
        }
    }
}
class Foo
{
    public List<Item> Items { get; set; }
}
class Item
{
    public int Id { get; set; }
    public string File { get; set; }
    public string Command { get; set; }
}

输出：

Id: 10
File: file1
Command: command 1
Id: 20
File: file2
Command: command 2
Id: 30
File: file3
Command: command 3

小提琴：https://dotnetfiddle.net/RXggvl

Answer 2

对于反序列化，您的 JSON 应该是这样的

{
   "items": [
      {Id: 10, File: "file1", Command: "command 1"},
      {Id: 20, File: "file2", Command: "command 2"},
      {Id: 30, File: "file3", Command: "command 3"}
   ]
}

这将在反序列化期间分别映射variables Id, File and Command to properties Id, File and Command

您可以使用以下代码反序列化它

public List<Item> DeserializeJSON(string jsonString)
{
    DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(List<Item>)); 
    MemoryStream stream = new MemoryStream(Encoding.UTF8.GetBytes(jsonString)); 
    var obj = (List<Item>)ser.ReadObject(stream);
    return obj;
}

Answer 3

为此，

您可以使用中间类型捕获从 Json 的转换，然后将其映射到Item类。所以首先我们有中间类：

public class IntermediateType
{
    public object[][] items { get; set; }
}

现在我们可以得到这样的结果：

var json = "{"items": [ [10, "file1", "command 1"], [20, "file2", "command 2"], [30, "file3", "command 3"] ]}";
var result = JsonConvert
    .DeserializeObject<IntermediateType>(json)
    .items
    .Select(o => new Item
    {
        Id = int.Parse(o[0].ToString()),
        File = (string)o[1],
        Command = (string)o[2]
    });