反序列化JSON陣列與鍵的字典從JSON

Question

我有一個JSON文件中像這樣單獨提供：

{ 
    "price": ["123.50", "124.6", "126.30"], 
    "order": ["23", "30", "20"] 
} 

我想，以填補我的對象Product：

public class Product { 
    public Dictionary<string, Object> priceInfo; 
    public Dictionary<string, Object> orderInfo; 
} 

我有各JSON對象每個值的描述（這裏有數組）可能在Product類中，例如：

String[] defPriceInfo = {"price", "avgprice", "maxprice"}; 

最後，我將訪問Product對象的這些數值與priceInfo.TryGetValue("avgprice", ...)，它將返回給我，我中搜索堆棧溢出值

124.6

，但我沒有找到一個類似的問題。 其實我試圖覆蓋JsonConverter.ReadJson，但它沒有奏效;問題是我想要的個性化「鑰匙」。

編輯1：我有這個ReadJson()方法，但這是錯誤的。

public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) 
     { 
      object res = new Object(); 
      var tokenType = reader.TokenType; 
      if (tokenType == JsonToken.StartObject) 
      { 
       object obj = serializer.Deserialize(reader); 
       res = new Dictionary<string, string>(); 
      } 
      else if (tokenType == JsonToken.StartArray) 
      { 
       res = serializer.Deserialize(reader); 
      } 
      return res; 
     } 

Answer 1

以下是一種使用自定義JsonConverter作爲通用解決方案的方法。這個想法是，你建立一個公共的，靜態的，只讀的字符串數組，包含你想要處理的每個字典的關鍵字，然後用[JsonConverter]屬性標記每個字典字段，該屬性指定在哪裏找到包含關鍵字數組的靜態字段。轉換器然後使用指定的鍵從JSON數組填充字典。 （請注意，如果JSON數組屬性的名字從你的類字典成員名稱不同，你還需要一個[JsonProperty]屬性綁在一起。）

這裏是你如何將它設置你的榜樣Product類：

public class Product 
{ 
    public static readonly string[] defPriceInfo = { "price", "avgprice", "maxprice" }; 
    public static readonly string[] defOrderInfo = { "first", "second", "third" }; 

    [JsonProperty("price")] 
    [JsonConverter(typeof(ArrayToDictionaryConverter), typeof(Product), "defPriceInfo")] 
    public Dictionary<string, object> priceInfo; 

    [JsonProperty("order")] 
    [JsonConverter(typeof(ArrayToDictionaryConverter), typeof(Product), "defOrderInfo")] 
    public Dictionary<string, object> orderInfo; 
} 

這裏是自定義ArrayToDictionaryConverter代碼：

class ArrayToDictionaryConverter : JsonConverter 
{ 
    private string[] keysArray; 

    public ArrayToDictionaryConverter(Type containingObjectType, string keysArrayFieldName) 
    { 
     FieldInfo field = containingObjectType.GetField(keysArrayFieldName); 
     if (field == null) 
      throw new Exception("Could not find " + keysArrayFieldName + " field on type " + containingObjectType.Name + "."); 
     if (!field.Attributes.HasFlag(FieldAttributes.Static) || field.FieldType != typeof(String[])) 
      throw new Exception("The " + keysArrayFieldName + " field on " + containingObjectType.Name + " must be declared as static string[]."); 
     keysArray = (string[])field.GetValue(null); 
    } 

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

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) 
    { 
     JArray array = JArray.Load(reader); 
     Dictionary<string, object> dict = new Dictionary<string, object>(); 

     for (int i = 0; i < array.Count; i++) 
     { 
      string key = i < keysArray.Length ? keysArray[i] : "key" + i; 
      dict.Add(key, (string)array[i]); 
     } 

     return dict; 
    } 

    public override bool CanWrite 
    { 
     get { return false; } 
    } 

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

這裏是在一個快速演示它是如何工作：

using System; 
using System.Collections.Generic; 
using System.Reflection; 
using Newtonsoft.Json; 
using Newtonsoft.Json.Linq; 

public class Program 
{ 
    public static void Main() 
    { 
     string json = @" 
      { 
       ""price"": [""123.50"", ""124.6"", ""126.30""], 
       ""order"": [""23"", ""30"", ""20""] 
      }"; 

     try 
     { 
      Product prod = JsonConvert.DeserializeObject<Product>(json); 
      foreach (var kvp in prod.priceInfo) 
      { 
       Console.WriteLine(kvp.Key + ": " + kvp.Value); 
      } 
      foreach (var kvp in prod.orderInfo) 
      { 
       Console.WriteLine(kvp.Key + ": " + kvp.Value); 
      } 
     } 
     catch (Exception e) 
     { 
      Console.WriteLine(e.Message); 
      if (e.InnerException != null) Console.WriteLine(e.InnerException.Message); 
     } 
    } 
} 

輸出：

price: 123.50 
avgprice: 124.6 
maxprice: 126.30 
first: 23 
second: 30 
third: 20 

Answer 2

你可以先反序列化JSON到POCO，例如使用這樣的類做到這一點：

public class TempProduct 
{ 
    public Price price {get; set;} 
    public Order order {get; set;} 

    public class Price 
    { 
    public string price {get; set;} 
    public string avgprice {get; set;} 
    public string maxprice {get; set;} 
    } 

    public class Order 
    { 
    public string orderType1 {get; set;} 
    public string orderType2 {get; set;} 
    public string orderType3 {get; set;} 
    } 
} 

然後你可以從這個例如填充您的產品類別

var prod = new Product(); 

prod.priceInfo = new Dictionary<string,Object>(); 
prod.priceInfo.Add("price", tempProd.price.price); 
prod.priceInfo.Add("avgprice", tempProd.price.avgprice); 
prod.priceInfo.Add("maxprice", tempProd.price.maxprice);