将对象序列化为 JSON 时 DataContract 框架不起作用

Question

这是我的模型：

namespace RESTalm
{
    [DataContract]
    [KnownType(typeof(Entity))]
    [KnownType(typeof(Field))]
    [KnownType(typeof(Value))]
    public class Entities
    {
        [DataMember(IsRequired = true)]
        public List<Entity> entities;

        [DataMember(IsRequired = true)]
        public int TotalResults;
    }

    [DataContract]
    [KnownType(typeof(Field))]
    [KnownType(typeof(Value))]
    public class Entity
    {
        [DataMember(IsRequired = true)]
        public Field[] Fields;

        [DataMember(IsRequired = true)]
        public String Type;
    }

    [DataContract]
    [KnownType(typeof(Value))]
    public class Field
    {
        [DataMember(IsRequired = true)]
        public String Name;

        [DataMember(IsRequired = true)]
        public Value[] values;
    }

    [DataContract]
    [KnownType(typeof(Value))]
    public class Value
    {
        [DataMember(IsRequired = true)]
        public String value;
    }    
}

这是我的程序：

        private String toJSON(Object poco)
        {
            String json;
            DataContractJsonSerializer jsonParser = new DataContractJsonSerializer(poco.GetType());
            MemoryStream buffer = new MemoryStream();

            jsonParser.WriteObject(buffer, poco);
            StreamReader reader = new StreamReader(buffer);
            json = reader.ReadToEnd();
            reader.Close();
            buffer.Close();

            return json;
    }

当对象 jsonParser 初始化时，它似乎根本无法识别我的模型。这导致空 MemoryStream()。请帮忙。

P.S。我在我的程序中删除了异常处理，因为它会分散注意力。谢谢。此外，目前对象 poco 始终被假定为我模型中的一种类型。

Answer 1

您需要通过重置其 Position 将流倒回到开头，然后才能从中读取，例如：

public static string ToJson<T>(T obj, DataContractJsonSerializer serializer = null)
{
    serializer = serializer ?? new DataContractJsonSerializer(obj == null ? typeof(T) : 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();
        }
    }
}

将对象序列化为 JSON 时 DataContract 框架不起作用

DataContract framework not working when serializing objects to JSON

c#

asp.net

json

datacontract