Question

当我使用DataContractJsonSerializer序列化枚举值时，它序列化枚举的数值，而不是字符串名称。

IE：

enum foo
{
   bar,
   baz
}

序列化foo.bar的值会返回“0”，而不是“bar”。

我更喜欢它，是否有办法覆盖这个？

编辑：

因为我不想更改序列化程序，所以我使用了一个简单的解决方法。

我在类中公开了一个属性，用于序列化调用ToString的值，即：

// Old
[DataMember]
public EnumType Foo
{
    get { return _foo; }
    set { _foo = value; }
}

// New, I still kept the EnumType but I only serialize the string version

public EnumType Foo
{
    get { return _foo; }
    set { _foo = value; }
}

[DataMember]
public string FooType
{
    get { return _foo.ToString(); }
    private set {}
}

Answer 1

It looks like this is by design并且无法更改此行为：

处理枚举成员值作为JSON中的数字，这是不同的从如何处理数据合同，包括在内会员名称。

以下是使用an alternative（以及更好，更可扩展的IMO）序列化程序实现您所需要的示例：

using System;
using Newtonsoft.Json;

class Program
{
    static void Main(string[] args)
    {
        var baz = Foo.Baz;
        var serializer = new JsonSerializer();
        serializer.Converters.Add(new JsonEnumTypeConverter());
        serializer.Serialize(Console.Out, baz);
        Console.WriteLine();
    }
}

enum Foo
{
    Bar,
    Baz
}

public class JsonEnumTypeConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(Foo);
    }
    public override void WriteJson(JsonWriter writer, object value)
    {
        writer.WriteValue(((Foo)value).ToString());
    }

    public override object ReadJson(JsonReader reader, Type objectType)
    {
        return Enum.Parse(typeof(Foo), reader.Value.ToString());
    }
}

Answer 2

要获得wcf json的2路序列化/去除，你可以添加第二个类型为string的get set属性，当你在javascript中构建你的json对象时，使用 string 命名属性，服务器端使用强类型枚举版本：例如

public class DTOSearchCriteria
{
    public int? ManufacturerID { get; set; }
    public int? ModelID { get; set; }


    private SortBy _sort;


    public SortBy SortType
    {
        get
        {
            return _sort;
        }
        set
        {
            _sort = value;
        }
    }

    public String Sort 
    {
        get
        {
            return _sort.ToString();
        }
        set
        {
            _sort = (SortBy) Enum.Parse(typeof(SortBy), value);
        }
    }





    public int PageSize { get; set; }
    public int PageNumber { get; set; }
}


public enum SortBy
{
    PriceDescending,
    PriceAscending
}

Answer 3

我疯狂地试图找到这个问题的优雅解决方案，因为似乎每个人都默认使用Newtonsoft的序列化程序来解决这个问题。尽管Newtonsoft提供了更多功能，但它确实存在一些严重缺陷。列举一些：对无参数构造函数的需求，如果你希望序列化实现IEnumerable的类的疯狂行为，并且在使用抽象类型时执行非常糟糕（因为它没有使用KnownTypes属性，并且变通方法生成一个将您的内部命名空间公开给调用者的详细输出。）

另一方面，在MVC4 WebApi解决方案中使用DataContractJsonSerializer时，几乎没有关于如何自定义DataContractJsonSerializer的示例。

我花了一段时间才找到一个表示枚举为字符串的解决方案，并解决了DataContractJsonSerializer附带的已知DateTime格式问题。

第一部分 - 将这些扩展方法放在扩展类中 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~

#region JSon

    /// <summary>Serializes an object to JSon.</summary>
    /// <param name="obj">The object to serialize.</param>
    /// <returns>Returns a byte array with the serialized object.</returns>
    /// <remarks>This implementation outputs dates in the correct format and enums as string.</remarks>
    [SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1650:ElementDocumentationMustBeSpelledCorrectly", Justification = "Reviewed.")]
    public static byte[] SerializeJson(this object obj)
    {
        using (MemoryStream b = new MemoryStream())
        {
            SerializeJson(obj, b);
            return b.ToArray();
        }
    }

    /// <summary>Serializes an object to JSon.</summary>
    /// <param name="obj">The object to serialize.</param>
    /// <param name="stream">The stream to write to.</param>
    /// <remarks>This implementation outputs dates in the correct format and enums as string.</remarks>
    [SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1650:ElementDocumentationMustBeSpelledCorrectly", Justification = "Reviewed.")]
    public static void SerializeJson(this object obj, Stream stream)
    {
        var settings = new DataContractJsonSerializerSettings();
        settings.DateTimeFormat = new System.Runtime.Serialization.DateTimeFormat("yyyy-MM-dd'T'HH:mm:ssZ");
        settings.DataContractSurrogate = new EnumToStringDataContractSurrogate();

        var type = obj == null ? typeof(object) : obj.GetType();

        var enumerationValue = obj as System.Collections.IEnumerable;

        var fixedValue = enumerationValue != null
                         ? type.IsGenericType && !type.GetGenericArguments()[0].IsInterface
                            ? enumerationValue.ToArray(type.GetGenericArguments()[0])
                            : enumerationValue.OfType<object>().ToArray()
                         : obj;

        if (enumerationValue != null && (!type.IsGenericType || (type.IsGenericType || type.GetGenericArguments()[0].IsInterface)))
        {
            var firstMember = (fixedValue as System.Collections.IEnumerable).OfType<object>().FirstOrDefault();
            if (firstMember != null)
                fixedValue = enumerationValue.ToArray(firstMember.GetType());
        }

        var fixedType = obj == null
                        ? type
                        : fixedValue.GetType();

        var jsonSer = new DataContractJsonSerializer(fixedType, settings);
        jsonSer.WriteObject(stream, fixedValue);
    }

    /// <summary>
    /// Deserializes an object.
    /// </summary>
    /// <typeparam name="T">The output type of the object.</typeparam>
    /// <param name="data">The serialized contents.</param>
    /// <returns>Returns the typed deserialized object.</returns>
    /// <remarks>This implementation outputs dates in the correct format and enums as string.</remarks>
    [SuppressMessage("Microsoft.Naming", "CA1702:CompoundWordsShouldBeCasedCorrectly", MessageId = "JSon")]
    [SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1650:ElementDocumentationMustBeSpelledCorrectly", Justification = "Reviewed.")]
    public static T DeserializeJSon<T>(this byte[] data)
    {
        using (MemoryStream b = new MemoryStream(data))
            return DeserializeJSon<T>(b);
    }

    /// <summary>Deserializes a JSon object.</summary>
    /// <typeparam name="T">The output type of the object.</typeparam>
    /// <param name="stream">The stream to read from.</param>
    /// <returns>Returns the typed object.</returns>
    /// <remarks>This implementation outputs dates in the correct format and enums as string.</remarks>
    [SuppressMessage("Microsoft.Naming", "CA1702:CompoundWordsShouldBeCasedCorrectly", MessageId = "JSon")]
    [SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1650:ElementDocumentationMustBeSpelledCorrectly", Justification = "Reviewed.")]
    public static T DeserializeJSon<T>(this Stream stream)
    {
        var settings = new DataContractJsonSerializerSettings();
        settings.DateTimeFormat = new System.Runtime.Serialization.DateTimeFormat("yyyy-MM-dd'T'HH:mm:ssZ");
        settings.DataContractSurrogate = new EnumToStringDataContractSurrogate();

        var jsonSer = new DataContractJsonSerializer(typeof(T), settings);
        return (T)jsonSer.ReadObject(stream);
    }

    /// <summary>Deserializes a JSon object.</summary>
    /// <param name="data">The serialized contents.</param>
    /// <param name="targetType">The target type.</param>
    /// <returns>Returns the typed deserialized object.</returns>
    /// <remarks>This implementation outputs dates in the correct format and enums as string.</remarks>
    [SuppressMessage("Microsoft.Naming", "CA1702:CompoundWordsShouldBeCasedCorrectly", MessageId = "JSon")]
    [SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1650:ElementDocumentationMustBeSpelledCorrectly", Justification = "Reviewed.")]
    public static object DeserializeJSon(this byte[] data, Type targetType)
    {
        using (MemoryStream b = new MemoryStream(data))
        {
            return DeserializeJSon(b, targetType);
        }
    }

    /// <summary>Deserializes a JSon object.</summary>
    /// <param name="data">The serialized contents.</param>
    /// <param name="targetType">The target type.</param>
    /// <returns>Returns the typed deserialized object.</returns>
    /// <remarks>This implementation outputs dates in the correct format and enums as string.</remarks>
    [SuppressMessage("Microsoft.Naming", "CA1702:CompoundWordsShouldBeCasedCorrectly", MessageId = "JSon")]
    [SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1650:ElementDocumentationMustBeSpelledCorrectly", Justification = "Reviewed.")]
    public static object DeserializeJSon(this Stream data, Type targetType)
    {
        var settings = new DataContractJsonSerializerSettings();
        settings.DateTimeFormat = new System.Runtime.Serialization.DateTimeFormat("yyyy-MM-dd'T'HH:mm:ssZ");
        settings.DataContractSurrogate = new EnumToStringDataContractSurrogate();

        var jsonSer = new DataContractJsonSerializer(targetType, settings);
        return jsonSer.ReadObject(data);            
    }

    /// <summary>Enumerator contract surrogate.</summary>
    internal class EnumToStringDataContractSurrogate : IDataContractSurrogate
    {
        Type IDataContractSurrogate.GetDataContractType(Type type)
        {
            return type == typeof(Enum) ? typeof(string) : type;
        }

        object IDataContractSurrogate.GetDeserializedObject(object obj, Type targetType)
        {
            if (targetType.IsEnum)
            {
                return obj == null
                       ? System.Enum.GetValues(targetType).OfType<int>().FirstOrDefault()
                       : System.Enum.Parse(targetType, obj.ToString());
            }
            return obj;
        }

        object IDataContractSurrogate.GetObjectToSerialize(object obj, Type targetType)
        {
            if (obj is Enum)
            {
                var pair = Enum.GetName(obj.GetType(), obj);
                return pair;
            }

            return obj;
        }

        object IDataContractSurrogate.GetCustomDataToExport(Type clrType, Type dataContractType)
        {
            throw new NotImplementedException();
        }

        object IDataContractSurrogate.GetCustomDataToExport(System.Reflection.MemberInfo memberInfo, Type dataContractType)
        {
            throw new NotImplementedException();
        }

        void IDataContractSurrogate.GetKnownCustomDataTypes(System.Collections.ObjectModel.Collection<Type> customDataTypes)
        {
            throw new NotImplementedException();
        }

        Type IDataContractSurrogate.GetReferencedTypeOnImport(string typeName, string typeNamespace, object customData)
        {
            throw new NotImplementedException();
        }

        System.CodeDom.CodeTypeDeclaration IDataContractSurrogate.ProcessImportedType(System.CodeDom.CodeTypeDeclaration typeDeclaration, System.CodeDom.CodeCompileUnit compileUnit)
        {
            throw new NotImplementedException();
        }
    }

    #endregion


    /// <summary>Creates an array from a non generic source.</summary>
    /// <param name="source">The source.</param>
    /// <param name="type">The target type of the array.</param>
    /// <returns>Returns a typed array.</returns>
    public static Array ToArray(this IEnumerable source, Type type)
    {
        var param = Expression.Parameter(typeof(IEnumerable), "source");
        var cast = Expression.Call(typeof(Enumerable), "Cast", new[] { type }, param);
        var toArray = Expression.Call(typeof(Enumerable), "ToArray", new[] { type }, cast);
        var lambda = Expression.Lambda<Func<IEnumerable, Array>>(toArray, param).Compile();

        return lambda(source);
    }

第二部分 - 通过封装DataContractJsonSerializer创建自己的格式化程序 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

/// <summary>Custom implementation of DataContract formatter.</summary>
public class DataContractJsonFormatter : MediaTypeFormatter
{

    /// <summary>Creates a new instance.</summary>
    public DataContractJsonFormatter()
    {
        SupportedMediaTypes.Add(new System.Net.Http.Headers.MediaTypeHeaderValue("application/json"));
    }

    /// <summary>Gets if the formatter the write a given type.</summary>
    /// <param name="type">The type to handle.</param>
    /// <returns>Returns if the formatter the write a given type.</returns>
    public override bool CanWriteType(Type type)
    {
        return true;
    }

    /// <summary>Gets if the formatter the read a given type.</summary>
    /// <param name="type">The type to handle.</param>
    /// <returns>Returns if the formatter the read a given type.</returns>
    public override bool CanReadType(Type type)
    {
        return true;
    }

    /// <summary>Deserializes an object.</summary>
    /// <param name="type">The target type.</param>
    /// <param name="readStream">The stream to read from.</param>
    /// <param name="content">The http content.</param>
    /// <param name="formatterLogger">A logger.</param>
    /// <returns>Returns the deserialized object.</returns>
    public override Task<object> ReadFromStreamAsync(Type type, Stream readStream, System.Net.Http.HttpContent content, IFormatterLogger formatterLogger)
    {
        var task = Task<object>.Factory.StartNew(() =>
        {
            return readStream.DeserializeJSon(type);
        });

        return task;
    }

    /// <summary>Serializes an object.</summary>
    /// <param name="type">The target type.</param>
    /// <param name="value">The object to serialize.</param>
    /// <param name="writeStream">The stream to write to.</param>
    /// <param name="content">The http content.</param>
    /// <param name="transportContext">The context.</param>
    /// <returns>Returns the deserialized object.</returns>
    public override Task WriteToStreamAsync(Type type, object value, Stream writeStream, System.Net.Http.HttpContent content, System.Net.TransportContext transportContext)
    {
        var task = Task.Factory.StartNew(() =>
        {
            value.SerializeJson(writeStream);
        });

        return task;
    }
}

第三部分 - 编辑Global.asax文件并使用新的JSon格式化程序 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~

    /// <summary>Event handlers of when the application starts.</summary>
    [SuppressMessage("Microsoft.Performance", "CA1822:MarkMembersAsStatic")]
    protected void Application_Start()
    {
       //Register my custom DataContract JSon serializer
        GlobalConfiguration.Configuration.Formatters.Insert(0, new DataContractJsonFormatter());

        //Register areas
        AreaRegistration.RegisterAllAreas();

        WebApiConfig.Register(GlobalConfiguration.Configuration);
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);
       // BundleConfig.RegisterBundles(BundleTable.Bundles);

        //JSON serialization config
        var json = GlobalConfiguration.Configuration.Formatters.JsonFormatter;
        json.UseDataContractJsonSerializer = false;
    }

Answer 4

编辑：抱歉刚起床不喝咖啡:(

以下是使用Json Serializer执行操作的代码，而不是DataContractJsonSerializer。

我还没有对DataContractJsonSerializer做过任何工作，但在快速扫描文档后，我对MS感到很失望。他们显然是极端地使WCF非常可扩展，但是使用DataContractJsonSerializer没有可扩展性。你必须使用MS风格的JSON。 MS的超级跛脚...已经弄乱了WCF。

    using System;
    using System.Collections.Generic;
    using System.Runtime.Serialization;
    using System.Web.Script.Serialization;

一些测试对象＆amp;枚举：

    public enum SomeSillyEnum
    {
        Foo,Bar,Doo,Daa,Dee
    }

    public class UseSillyEnum
    {
        public SomeSillyEnum PublicEnum { get; set; }
        public string SomeOtherProperty { get; set; }
        public UseSillyEnum()
        {
            PublicEnum = SomeSillyEnum.Foo;
            SomeOtherProperty = "Testing";
        }
    }

JavaScriptConverters。一个用于所有枚举，一个用于使用枚举的对象。

public class EnumStringConverter : JavaScriptConverter
{
    public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
    {
        foreach(string key in dictionary.Keys)
        {
            try { return Enum.Parse(type, dictionary[key].ToString(), false); }
            catch(Exception ex) { throw new SerializationException("Problem trying to deserialize enum from JSON.",ex); }
        }
        return Activator.CreateInstance(type);
    }

    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
    {
        Dictionary<string,object> objs = new Dictionary<string, object>();
        objs.Add(obj.ToString(), ((Enum)obj).ToString("D"));
        return objs;
    }

    public override IEnumerable<Type> SupportedTypes{get {return new Type[] {typeof (Enum)};}}
}

public class SillyConverter : JavaScriptConverter
{
    public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
    {
        UseSillyEnum se = new UseSillyEnum();
        foreach (string key in dictionary.Keys)
        {
            switch(key)
            {
                case "PublicEnum":
                    se.PublicEnum = (SomeSillyEnum) Enum.Parse(typeof (SomeSillyEnum), dictionary[key].ToString(), false);
                    break;
                case "SomeOtherProperty":
                    se.SomeOtherProperty = dictionary[key].ToString();
                    break;
            }
        }
        return se;
    }

    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
    {
        UseSillyEnum se = (UseSillyEnum)obj;
        Dictionary<string, object> objs = new Dictionary<string, object>();
        objs.Add("PublicEnum", se.PublicEnum);
        objs.Add("SomeOtherProperty", se.SomeOtherProperty);
        return objs;
    }

    public override IEnumerable<Type> SupportedTypes { get { return new Type[] { typeof(UseSillyEnum) }; } }
}

在页面中使用它：

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
        /* Handles ALL Enums

        JavaScriptSerializer jsonSer = new JavaScriptSerializer(); 
        jsonSer.RegisterConverters( new JavaScriptConverter[] { new EnumStringConverter() } );

        string json = jsonSer.Serialize(new UseSillyEnum());
        Response.Write(json);

        UseSillyEnum obj = jsonSer.Deserialize<UseSillyEnum>(json);
        Response.Write(obj.PublicEnum);

        */

        /* Handles Object that uses an enum */
        JavaScriptSerializer jsonSer = new JavaScriptSerializer();
        jsonSer.RegisterConverters( new JavaScriptConverter[] { new SillyConverter() } );
        string json = jsonSer.Serialize(new UseSillyEnum());
        Response.Write(json);

        UseSillyEnum obj = jsonSer.Deserialize<UseSillyEnum>(json);
        Response.Write(obj.PublicEnum);
    }
}

Answer 5

我已经使用Newtonsoft.Json库以WCF中的方式组合了此解决方案的所有部分。它修复了枚举问题并使错误处理更好，并且可以在IIS托管服务中使用。这是很多代码，所以你可以在GitHub上找到它：https://github.com/jongrant/wcfjsonserializer/blob/master/NewtonsoftJsonFormatter.cs

您必须向Web.config添加一些条目才能使其正常工作，您可以在此处查看示例文件： https://github.com/jongrant/wcfjsonserializer/blob/master/Web.config

DataContractJsonSerializer和Enums

5 个答案: