RestSharp 不反序列化 JSON 对象列表，始终为空

Question

I'm having a problem with RestSharp deserializing the return content into my classes. From all my searching it seems that I am doing this correctly. I would much rather use RestSharp's deserializer than have to fall back to another package like Newstonsoft's Json.NET.

What I am doing is making a API request to GoToWebinar for all list of scheduled Webinars:

var client = new RestClient(string.Format("https://api.citrixonline.com/G2W/rest/organizers/{0}/upcomingWebinars", "300000000000239000"));
var request = new RestRequest(Method.GET);
request.AddHeader("Authorization", "OAuth oauth_token=" + System.Configuration.ConfigurationManager.AppSettings["GoToWebinar"]);
var response2 = client.Execute<List<RootObject>>(request);

As you see I would like to get a list of object 'RootObject' (as shown below). I am receiving the following JSON response in response2.Content:

[
   {
      "webinarKey":678470607,
      "subject":"Easton's Wild Rice Cooking Demo",
      "description":"Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
      "organizerKey":300000000000239551,
      "times":[{"startTime":"2012-05-09T15:00:00Z","endTime":"2012-05-09T16:00:00Z"}],
      "timeZone":"America/Denver"
   },
   {
      "webinarKey":690772063,
      "subject":"Easton's Match Making Service",
      "description":"Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
      "organizerKey":300000000000239551,
      "times":[{"startTime":"2012-05-09T15:00:00Z","endTime":"2012-05-09T16:00:00Z"}],
      "timeZone":"America/Denver"
   }
]

I created the following objects using http://json2csharp.com using the JSON results above:

public class RootObject
{
    public int webinarKey { get; set; }
    public string subject { get; set; }
    public string description { get; set; }
    public long organizerKey { get; set; }
    public List<Time> times { get; set; }
    public string timeZone { get; set; }
}

public class Time
{
    public string startTime { get; set; }
    public string endTime { get; set; }
}

The problem is response2.Data is always Null. For some reason the deserialization failed and I do not know why. My goal is to be able to use a foreach loop to iterate through the results:

foreach(RootObject r in response2.Data)
{
    lblGoToWebinar.Text += r.webinarKey.ToString() + ", ";
}

Any ideas on why the deserialization is failing?

Answer 1

Based on the @agarcian's suggestion above, I googled the error:

restsharp Data at the root level is invalid. Line 1, position 1.

and found this forum: http://groups.google.com/group/restsharp/browse_thread/thread/ff28ddd9cd3dde4b

Basically, I was wrong to assume that client.Execute was going to be able to auto-detect the return content type. It needs to be explicity set:

var request = new RestRequest(Method.GET);
request.OnBeforeDeserialization = resp => { resp.ContentType = "application/json"; };

This could be cited more clearly in RestSharp's documentation. Hopefully this will help someone else out!

Answer 2

Late to the party: You would need to find the actual Content-Type of the response you were getting. The server doesn't necessarily respond with any of the content types from your request's Accept header. For Google's APIs I got a text/plain response, so this advice from the group worked for me.

public T Execute<T>(string url, RestRequest request) where T : new()
{
    var client = new RestClient();
    // tell RestSharp to decode JSON for APIs that return "Content-Type: text/plain"
    client.AddHandler("text/plain", new JsonDeserializer());
    ...

It's also tidier if it can be done in one place such as the shared Execute method above, rather than forcing the response type with OnBeforeDeserialization wherever each request is created.

Answer 3

I had this same problem, and none of the answers above helped.

Here was my response class:

public class SomeResponse
{
    public string string1;
    public string string2;
}

The problem was human error - I forgot to include the get/set accessors. I don't often use C# and forgot the need for them.

public class SomeResponse
{
    public string string1 { get; set; }
    public string string2 { get; set; }
}

Hope this helps someone out there.