Deserializing JSON using dynamic datatype in WinRT

Question

I was lately trying to deserialize JSON content using JSON.Net API with dynamic datatype.

I searched the forum really hard and found out that it is indeed possible to do so in WinRT.

A sample JSON could be:

string json = "{\"message\":\"Sample Message\"}"

I used the following format:

dynamic result = JsonConvert.DeserializeObject<dynamic>(json);

It successfully deserializes the content to result. But when I try to access it using a syntax like:

string message = result.message;

It results in an error which is:

'object' does not contain a definition for 'message' and no extension method 'message' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?)

I tried with many json samples all over the internet but the error remains the same. Truly speaking, I tried it a some hours back it ACTUALLY worked! But I couldn't find what I am missing this time.

PS: I need to use dynamic only because my actual Json contains dynamic field names. Once it is like:

{"New York" : "Its in United States"}

And sometimes it is like:

{"London" : "Its in United Kingdom"}

(Crap example though! :P ) The json2csharp classes method won't work here I guess and if there is some secondary and more efficient method. Please guide me in. The real Json which I am trying to parse is very complex. I would post it if it needs to be posted.

Answer 1

I use JSON.NET in a personal project of mine, but deserialize using square bracket syntax like this:

Id = jsonResult["object_id"].ToObject<int>(),

To actually get the JSON object I do this:

var response = await client.GetStringAsync(parameters);
var jsonResult = JToken.Parse(response)["results"].Children();

I adopted this methodology after doing a good bit of research into the different ways to use JSON.NET. I seriously considered going the dynamic route after reading this article: http://www.west-wind.com/weblog/posts/2012/Aug/30/Using-JSONNET-for-dynamic-JSON-parsing

However, in the end I decided against dynamic objects because when I fill my normal objects with the square bracket syntax I return immediately to a strongly-typed environment where intellisense will begin to catch any errors I may make. I combine this with a LINQ query and fill a set of fairly complex objects in a relatively few number of lines.

For me, dynamic objects are one more weakly-typed step in the deserialization process that I prefer to avoid if possible.

Answer 2

I'm not really sure what you try to do but maybe this will help:

[TestCase("{\"message\":\"Sample Message\"}", "Sample Message")]
[TestCase("{\"New York\" : \"Its in United States\"}", "Its in United States")]
[TestCase("{\"London\" : \"Its in United Kingdom\"}", "Its in United Kingdom")]
public void TestNameTest(string json, string expected)
{
    var result = JObject.Parse(json);
    var value = result.Values().Single();
    var jValue = new JValue(expected);
    Assert.AreEqual( jValue,value);
}