如何将具有固定架构的值数组反序列化为强类型数据类?

Pat*_*ick 2 .net c# serialization json json.net

我在找出以特定格式反序列化某些 JSON 数据的干净(尽可能)方法时遇到了一些麻烦。我想将数据反序列化为强类型数据对象类,这在细节方面非常灵活。以下是数据外观的示例:

{
    "timestamp": 1473730993,
    "total_players": 945,
    "max_score": 8961474,
    "players": {
            "Player1Username": [
            121,
            "somestring",
            679900,
            5,
            4497,
            "anotherString",
            "thirdString",
            "fourthString",
            123,
            22,
            "YetAnotherString"],
        "Player2Username": [
            886,
            "stillAstring",
            1677,
            1,
            9876,
            "alwaysAstring",
            "thirdString",
            "fourthString",
            876,
            77,
            "string"]
        }
}
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我不确定的具体部分是:

  1. 玩家的合集会被认为是一本字典吗?用户名可以作为键,但值让我失望,因为它是字符串和整数值的混合集合。
  2. 玩家完全由未命名的值组成。我几乎总是使用具有命名属性和值的 JSON 数据(例如时间戳、total_players 等在最顶部)

假设我有一个这样的顶级课程:

public class ScoreboardResults
{
    public int timestamp { get; set; }
    public int total_players { get; set; }
    public int max_score { get; set; }
    public List<Player> players { get; set; }
}
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如果 Player 对象基本上是一个以用户名作为键的键/值,并且该值是混合整数和字符串的集合,那么它会是什么样子?每个玩家元素的数据总是以相同的顺序排列,所以我知道集合中的第一个值是他们的 UniqueID,第二个值是玩家描述,等等。我希望玩家类是这样的:

public class Player
{
    public string Username { get; set; }
    public int UniqueID { get; set; }
    public string PlayerDescription { get; set; }
    ....
    ....
    .... Following this pattern for all of the values in each player element
    ....
    ....
}
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我确信这是使用 JSON.NET 做的一件非常简单的事情,这就是为什么我想避免我对如何实现这一点的任何想法。我想出的东西是不优雅的,并且可能在序列化过程中在某种程度上容易出错。

编辑

以下是根据snow_FFFFFF 的建议使用过去作为 JSON 类时生成的类:

public class Rootobject
{
    public int timestamp { get; set; }
    public int total_players { get; set; }
    public int max_score { get; set; }
    public Players players { get; set; }
}

public class Players
{
    public object[] Player1Username { get; set; }
    public object[] Player2Username { get; set; }
}
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我不清楚的是如何将“players”元素中的 JSON 数据反序列化为 List,其中 Player1Username 是 Player 对象上的一个简单字符串属性。至于混合字符串和整数的集合,我相信我可以毫无问题地将它们放入 Player 对象的各个属性中。

sno*_*FFF 5

一个好的开始方法是让 Visual Studio 基于 JSON 生成您的类。打开一个空白类文件,然后转到“编辑”->“特殊粘贴”->“将 JSON 粘贴为类”。

这将生成一个包含序列化/反序列化 JSON 所需类的文件。


dbc*_*dbc 5

在 Visual Basic .NET 中反序列化 JSON的转换应该可以满足您的需求,从 VB.NET 适当地转换为 c#:

public class ObjectToArrayConverter<T> : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return typeof(T) == objectType;
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        var objectType = value.GetType();
        var contract = serializer.ContractResolver.ResolveContract(objectType) as JsonObjectContract;
        if (contract == null)
            throw new JsonSerializationException(string.Format("invalid type {0}.", objectType.FullName));
        writer.WriteStartArray();
        foreach (var property in SerializableProperties(contract))
        {
            var propertyValue = property.ValueProvider.GetValue(value);
            if (property.Converter != null && property.Converter.CanWrite)
                property.Converter.WriteJson(writer, propertyValue, serializer);
            else
                serializer.Serialize(writer, propertyValue);
        }
        writer.WriteEndArray();
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        var contract = serializer.ContractResolver.ResolveContract(objectType) as JsonObjectContract;
        if (contract == null)
            throw new JsonSerializationException(string.Format("invalid type {0}.", objectType.FullName));

        if (reader.MoveToContentAndAssert().TokenType == JsonToken.Null)
            return null;
        if (reader.TokenType != JsonToken.StartArray)
            throw new JsonSerializationException(string.Format("token {0} was not JsonToken.StartArray", reader.TokenType));

        // Not implemented: JsonObjectContract.CreatorParameters, serialization callbacks, 
        existingValue = existingValue ?? contract.DefaultCreator();

        using (var enumerator = SerializableProperties(contract).GetEnumerator())
        {
            while (true)
            {
                switch (reader.ReadToContentAndAssert().TokenType)
                {
                    case JsonToken.EndArray:
                        return existingValue;

                    default:
                        if (!enumerator.MoveNext())
                        {
                            reader.Skip();
                            break;
                        }
                        var property = enumerator.Current;
                        object propertyValue;
                        // TODO:
                        // https://www.newtonsoft.com/json/help/html/Properties_T_Newtonsoft_Json_Serialization_JsonProperty.htm
                        // JsonProperty.ItemConverter, ItemIsReference, ItemReferenceLoopHandling, ItemTypeNameHandling, DefaultValue, DefaultValueHandling, ReferenceLoopHandling, Required, TypeNameHandling, ...
                        if (property.Converter != null && property.Converter.CanRead)
                            propertyValue = property.Converter.ReadJson(reader, property.PropertyType, property.ValueProvider.GetValue(existingValue), serializer);
                        else
                            propertyValue = serializer.Deserialize(reader, property.PropertyType);
                        property.ValueProvider.SetValue(existingValue, propertyValue);
                        break;
                }
            }
        }
    }

    static IEnumerable<JsonProperty> SerializableProperties(JsonObjectContract contract)
    {
        return contract.Properties.Where(p => !p.Ignored && p.Readable && p.Writable);
    }
}

public static partial class JsonExtensions
{
    public static JsonReader ReadToContentAndAssert(this JsonReader reader)
    {
        return reader.ReadAndAssert().MoveToContentAndAssert();
    }

    public static JsonReader MoveToContentAndAssert(this JsonReader reader)
    {
        if (reader == null)
            throw new ArgumentNullException();
        if (reader.TokenType == JsonToken.None)       // Skip past beginning of stream.
            reader.ReadAndAssert();
        while (reader.TokenType == JsonToken.Comment) // Skip past comments.
            reader.ReadAndAssert();
        return reader;
    }

    public static JsonReader ReadAndAssert(this JsonReader reader)
    {
        if (reader == null)
            throw new ArgumentNullException();
        if (!reader.Read())
            throw new JsonReaderException("Unexpected end of JSON stream.");
        return reader;
    }
}
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接下来,将转换器添加到您的Player类中,并使用JsonPropertyAttribute.Order以下命令指示每个属性的顺序:

[JsonConverter(typeof(ObjectToArrayConverter<Player>))]
public class Player
{
    [JsonProperty(Order = 1)]
    public int UniqueID { get; set; }
    [JsonProperty(Order = 2)]
    public string PlayerDescription { get; set; }
    // Other fields as required.
}
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最后,按如下方式声明您的根对象:

public class ScoreboardResults
{
    public int timestamp { get; set; }
    public int total_players { get; set; }
    public int max_score { get; set; }
    public Dictionary<string, Player> players { get; set; }
}
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请注意,我已经感动Username了的Player阶级和进入词典,作为重点。

请注意,可以使用数据协定属性代替 Newtonsoft 属性来指定顺序:

[JsonConverter(typeof(ObjectToArrayConverter<Player>))]
[DataContract]
public class Player
{
    [DataMember(Order = 1)]
    public int UniqueID { get; set; }
    [DataMember(Order = 2)]
    public string PlayerDescription { get; set; }
    // Other fields as required.
}
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演示在这里这里这里摆弄。