使用Json.net反序列化时出现“意外的令牌：StartObject”

Question

I have the following JSON that a C# WebClient returned:

"\n\n\n{\n \"resultCount\":1,\n \"results\": [\n{\"wrapperType\":\"artist\", \"artistType\":\"Artist\", \"artistName\":\"Jack Johnson\", \"artistLinkUrl\":\"http://itunes.apple.com/us/artist/jack-johnson/id909253?uo=4\", \"artistId\":909253, \"amgArtistId\":468749, \"primaryGenreName\":\"Rock\", \"primaryGenreId\":21}]\n}\n\n\n"

or, more clearly:

{
   "resultCount ":1,
   "results ":[
      {
         "wrapperType ":"artist ",
         "artistType ":"Artist ",
         "artistName ":"Jack Johnson ",
         "artistLinkUrl ":"http://itunes.apple.com/us/artist/jack-johnson/id909253?uo=4 ",
         "artistId ":909253,
         "amgArtistId ":468749,
         "primaryGenreName ":"Rock ",
         "primaryGenreId ":21
      }
   ]
}

I've tried deserializing this to a class, like so:

 thejsonresult = JsonConvert.DeserializeObject<JsonResult>(WebRequest.Json);

but received the following error:

Error reading string. Unexpected token: StartObject. Line 7, position 2.

I'm pretty lost and can't find any documentation on this. Anyone got a clue?

Answer 1

I believe the problem is actually to be found in the class to which you are attempting to deserialise.

The wrapper property you have is not being deserialised to correctly. If it is an object in your class, then it should work, but if it is a string, which I am guessing, then the Json deserialiser will try to deserialise it and find it's not a string.

Answer 2

This doesn't throw any exceptions for me in LINQPad:

JsonConvert.DeserializeObject<JsonResult>("\n\n\n{\n \"resultCount\":1,\n \"results\": [\n{\"wrapperType\":\"artist\", \"artistType\":\"Artist\", \"artistName\":\"Jack Johnson\", \"artistLinkUrl\":\"http://itunes.apple.com/us/artist/jack-johnson/id909253?uo=4\", \"artistId\":909253, \"amgArtistId\":468749, \"primaryGenreName\":\"Rock\", \"primaryGenreId\":21}]\n}\n\n\n")

If you're getting different results, you may want to try a different version of JSON.NET to see if it's a bug.

Answer 3

I recently ran into the same type of de-serializing exception, “Unexpected token: StartObject”, using the string from the serialization result.

Seems the property declaration of the target cannot be the same name as the object type. In my case the object being de-serialized had a property of ZipCode which was a class of ZipCode.

Ultimately, changing the property name to something other than the class name resolved the exception.