C# – Cannot find JavaScriptSerializer in .Net 4.0

I have found that Json.NET provides the exact functionality I'm looking for with a StringEnumConverter attribute:

using Newtonsoft.Json;
using Newtonsoft.Json.Converters;

[JsonConverter(typeof(StringEnumConverter))]
public Gender Gender { get; set; }

More details at available on StringEnumConverter documentation.

There are other places to configure this converter more globally:

• enum itself if you want enum always be serialized/deserialized as string:

  [JsonConverter(typeof(StringEnumConverter))]  
  enum Gender { Male, Female }
  

• In case anyone wants to avoid attribute decoration, you can add the converter to your JsonSerializer (suggested by Bjørn Egil):

  serializer.Converters.Add(new Newtonsoft.Json.Converters.StringEnumConverter()); 
  

  and it will work for every enum it sees during that serialization (suggested by Travis).

• or JsonConverter (suggested by banana):

  JsonConvert.SerializeObject(MyObject, 
      new Newtonsoft.Json.Converters.StringEnumConverter());
  

Additionally you can control casing and whether numbers are still accepted by using StringEnumConverter(NamingStrategy, Boolean) constructor.

In order to use a CLR 2.0 mixed mode assembly, you need to modify your App.Config file to include:

<?xml version="1.0"?>
<configuration>
  <startup useLegacyV2RuntimeActivationPolicy="true">
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
  </startup>
</configuration>

The key is the useLegacyV2RuntimeActivationPolicy flag. This causes the CLR to use the latest version (4.0) to load your mixed mode assembly. Without this, it will not work.

Note that this only matters for mixed mode (C++/CLI) assemblies. You can load all managed CLR 2 assemblies without specifying this in app.config.