C# JSON decoding using Web Matrix helpers

Question

I've been searching for a while for a nice and clean way to convert a JSON object to a dynamic object.

(I could cast to an object but the Twitter Streaming API actually sends two different JSON objects with the possibility of future object types!)

The code I use currently is from:

Deserialize JSON into C# dynamic object?

But its not the cleanest code and I was playing around with Web Matrix and noticed that they have a nice JSON.Decode(string) and JSON.Encode(object) methods and wanted to make use of them.

http://msdn.microsoft.com/en-us/library/system.web.helpers.json(v=vs.99).aspx

Adding a reference to System.Web.Helpers to my C# console application I managed to compile a solution calling JSON.Decode but... it throws a nasty exception.

This is probably down to me using it in a way not intended (outside Web Matrix) but any ideas? Probably expecting a simple, no thats silly answer ;-)

Attempt by method 'System.Web.Helpers.Json.Decode(System.String)' to access field 'System.Web.Helpers.Json._serializer' failed.

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I'm using VS2010.

More detail: System.FieldAccessException was caught Message=Attempt by method 'System.Web.Helpers.Json.Decode(System.String)' to access field 'System.Web.Helpers.Json._serializer' failed. Source=System.Web.Helpers StackTrace: at System.Web.Helpers.Json.Decode(String value) at Components.DataCollection.ConvertTwitterStream.ConvertTweets() in C:\Users\Administrator\documents\visual studio 2010\Projects\ISMM\Components\DataCollection\ConvertTwitterStream.cs:line 35 InnerException:

Answer 1

Debugging calls to 'Json.Decode' fail when the Visual Studio hosting process is enabled (which is the default). I found it worked with the hosting process disabled or when running without the debugger.

The hosting process can be disabled for your project by following these instructions: http://msdn.microsoft.com/en-us/library/ms185330.aspx

Answer 2

To support jbtule's answer, JsonFx v2 (http://github.com/jsonfx/jsonfx) makes this really easy. The example below shows a full round-trip with dynamic object being built from a JSON string and then serialized back into JSON.

string input = "{ \"foo\": true, \"array\": [ 42, false, \"Hello!\", null ] }";
dynamic value = new JsonReader().Read(input);
// verify that it works
Console.WriteLine(value.foo); // true
Console.WriteLine(value.array[0]); // 42
Console.WriteLine(value.array.Length); // 4

string output = new JsonWriter().Write(value);
// verify that it works
Console.WriteLine(output); // {"foo":true,"array":[42,false,"Hello!",null]}