Newtonsoft Json.NET for Unity3D
Newtonsoft Json.NET is a de facto standard JSON library in .NET ecosystem. But it doesn't support Unity3D, so it's a little bit hard to use JSON.NET just after getting Json.NET package. This package is for Unity3D programmers that need to use latest Json.NET in Unity3D.
Where can I get it?
Visit Release page to get latest Json.NET unity-package.
What's the deal?
Unity3D has old-fashioned and bizarre .NET Framework like these :)
- Basically based on .NET Framework 3.5 (forked Mono 2.6)
- Runtime lacks some types in .NET Framework 3.5 (like System.ComponentModel.AddingNewEventHandler)
- For iOS, dynamic code emission is forbidden by Apple AppStore.
Because Newtonsoft Json.NET doesn't handle these limitations, errors will welcome you when you use official Json.NET dll targetting .NET 3.5 Framework.
Following works are done to make Json.NET support Unity3D.
- Based on Newtonsoft Json.NET 9.
- Disable IL generation to work well under AOT environment like iOS.
- Remove code related with System.ComponentModel.
- Remove System.Data and EntityKey support.
- Remove XML support.
- Remove DiagnosticsTraceWriter support.
- Workaround for differences between Microsoft.NET & Unity3D-Mono.NET
For Unity.Lite version, additional works are done to make more lite.
- Remove JsonLinq, JPath (JToken, ...)
- Remove Bson
Tests in Json.NET are updated to be able to run under UnityEditor Test Runner. All tests pass under Microsoft .NET 3.5 but with UnityEditor some of them fail because there are not-implemented features and bugs in Unity3D-Mono framework.
Detailed Description is here to tell you what failed and why.
This library is tested on Unity 4.7, 5.2 and 5.3. For AOT environment like iOS, you need to use IL2CPP instead of obsolute Mono-AOT because IL2CPP handles generic code better than Mono-AOT. With Mono-AOT configuration, AOT related exception would be thrown.
For windows store build, there is a compatibility issue related with UWP. If you have a problem, please read workaround for UWP.
MissingMethodException is thrown for
MissingMethodException: Method not found: Default constructor not found...ctor() of System.ComponentModel.TypeConverter.
Make sure that
link.xml is added to your project.
ExecutionEngineException is thrown in calling
xecutionEngineException: Attempting to call method 'CLASS::.cctor' for which no ahead of time (AOT) code was generated. at System.Reflection.MonoCMethod.Invoke (...) at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal
This exception is thrown because Unity3D strips out unnecessary classes which are actually used by serialization.
To fix this problem, just put
new CLASS() in your code to prevent Unity3D from removing the class.
ArgumentNullException is thrown in calling
ArgumentNullException: Argument cannot be null. Parameter name: method at Newtonsoft.Json.Utilities.ValidationUtils.ArgumentNotNull (...) at Newtonsoft.Json.Utilities.LateBoundReflectionDelegateFactory.CreateParameterizedConstructor (...)
This is similar with the previous case. But this case is tricky because this is
caused by Json.NET internal classes such as
To fix this problem, put
AotHelper.EnsureList<T>() if you use
AotHelper.EnsureDictionary<TKey, TValue>() if you use
Dictionary<TKey, TValue> in working class.