如何将 ISerializable 对象序列化为 SOAP 或 Json 或 Xml

Question

我有一个 ISerializable 的复杂对象，我想将它序列化为一个 XML 文档（我宁愿不更改源代码并添加 XML 序列化属性的节点）。 ISerializable 可以很好地与 BinaryFormatter 配合使用，但是没有标准的方法可以将其序列化为 XML 或 Json。 Json.NET 库确实支持将 ISerializable 对象序列化为 json，但是该实现有一个非常小的问题，那就是 class 的可序列化构造函数应该是 public 以便 Json.net 检测到它（参见 this issue），这确实使 Json.net 无法用于我的情况。

有没有其他方法可以serialize/deserialize ISerializable object to/from xml, Json 或任何其他平面文本格式？

Answer 1

DataContractSerializer and DataContractJsonSerializer both support ISerializable. See Types Supported by the Data Contract Serializer。

例如，考虑以下 class：

[Serializable]
public class SerializableClass : ISerializable
{
    readonly int valueField;

    public SerializableClass(int valueField)
    {
        this.valueField = valueField;
    }

    public int Value { get { return valueField; } }

    #region ISerializable Members

    protected SerializableClass(SerializationInfo info, StreamingContext context)
    {
        this.valueField = info.GetInt32("valueField");
    }

    void ISerializable.GetObjectData(SerializationInfo info, StreamingContext context)
    {
        info.AddValue("valueField", valueField);
    }

    #endregion
}

以及以下辅助方法：

public static partial class DataContractSerializerHelper
{
    public static string SerializeXml<T>(T obj, DataContractSerializer serializer = null, XmlWriterSettings settings = null)
    {
        serializer = serializer ?? new DataContractSerializer(obj.GetType());
        using (var textWriter = new StringWriter())
        {
            settings = settings ?? new XmlWriterSettings { Indent = true, IndentChars = "    " };
            using (var xmlWriter = XmlWriter.Create(textWriter, settings))
            {
                serializer.WriteObject(xmlWriter, obj);
            }
            return textWriter.ToString();
        }
    }

    public static T DeserializeXml<T>(string xml, DataContractSerializer serializer = null)
    {
        using (var textReader = new StringReader(xml ?? ""))
        using (var xmlReader = XmlReader.Create(textReader))
        {
            return (T)(serializer ?? new DataContractSerializer(typeof(T))).ReadObject(xmlReader);
        }
    }
}

public static partial class DataContractJsonSerializerHelper
{
    private static MemoryStream GenerateStreamFromString(string value)
    {
        return new MemoryStream(Encoding.Unicode.GetBytes(value ?? ""));
    }

    public static string SerializeJson<T>(T obj, DataContractJsonSerializer serializer = null)
    {
        serializer = serializer ?? new DataContractJsonSerializer(obj.GetType());
        using (var memory = new MemoryStream())
        {
            serializer.WriteObject(memory, obj);
            memory.Seek(0, SeekOrigin.Begin);
            using (var reader = new StreamReader(memory))
            {
                return reader.ReadToEnd();
            }
        }
    }

    public static T DeserializeJson<T>(string json, DataContractJsonSerializer serializer = null)
    {
        serializer = serializer ?? new DataContractJsonSerializer(typeof(T));
        using (var stream = GenerateStreamFromString(json))
        {
            var obj = serializer.ReadObject(stream);
            return (T)obj;
        }
    }
}

然后

var test = new SerializableClass(42);

var xml = DataContractSerializerHelper.SerializeXml(test);
Debug.WriteLine(xml);

生产

<SerializableClass xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:x="http://www.w3.org/2001/XMLSchema" xmlns="http://schemas.datacontract.org/2004/07/Question38188639">
    <valueField i:type="x:int" xmlns="">42</valueField>
</SerializableClass>

和

var json = DataContractJsonSerializerHelper.SerializeJson(test);
Debug.WriteLine(json);

生产

{"valueField":42}

Answer 2

Json.NET 实际上支持 ISerializable 类型的非公共流序列化构造函数。如需确认，请参阅 DefaultContractResolver.CreateISerializableContract().

的源代码

你的实际问题是 ISerializable type in question is also a collection, and it appears Json.NET uses an array contract in preference to a JsonISerializableContract for such types, as shown in DefaultContractResolver.CreateContract():

        if (typeof(IEnumerable).IsAssignableFrom(t))
        {
            return CreateArrayContract(objectType);
        }

        if (CanConvertToString(t))
        {
            return CreateStringContract(objectType);
        }

#if !(DOTNET || PORTABLE40 || PORTABLE)
        if (!IgnoreSerializableInterface && typeof(ISerializable).IsAssignableFrom(t))
        {
            return CreateISerializableContract(objectType);
        }
#endif

要解决此问题，您可以创建自己的 custom contract resolver 来反转此逻辑：

public class ISerializableCollectionContractResolver : DefaultContractResolver
{
    protected override JsonContract CreateContract(Type objectType)
    {
        var contract = base.CreateContract(objectType);
        var underlyingType = Nullable.GetUnderlyingType(objectType) ?? objectType;

        if (!IgnoreSerializableInterface 
            && typeof(ISerializable).IsAssignableFrom(underlyingType)
            && contract is JsonArrayContract
            && !underlyingType.GetCustomAttributes<JsonContainerAttribute>().Any())
        {
            contract = CreateISerializableContract(objectType);
        }

        return contract;
    }
}

您的自定义集合现在应该通过它们的 ISerializable 接口序列化。

您可能想要。

如何将 ISerializable 对象序列化为 SOAP 或 Json 或 Xml

How to serialize an ISerializable object into SOAP or Json or Xml

serialization

json.net

iserializable