Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1

To make it clear, in addition to @SLaks' answer, that meant you need to change this line :

List<RootObject> datalist = JsonConvert.DeserializeObject<List<RootObject>>(jsonstring);

to something like this :

RootObject datalist = JsonConvert.DeserializeObject<RootObject>(jsonstring);

As the error message is trying very hard to tell you, you can't deserialize a single object into a collection (List<>).

You want to deserialize into a single RootObject.

That happened to me too, because I was trying to get an IEnumerable but the response had a single value. Please try to make sure it's a list of data in your response. The lines I used (for api url get) to solve the problem are like these:

HttpResponseMessage response = await client.GetAsync("api/yourUrl");if (response.IsSuccessStatusCode){    IEnumerable<RootObject> rootObjects =        awaitresponse.Content.ReadAsAsync<IEnumerable<RootObject>>();    foreach (var rootObject in rootObjects)    {        Console.WriteLine(            "{0}\t${1}\t{2}",            rootObject.Data1, rootObject.Data2, rootObject.Data3);    }    Console.ReadLine();}

Hope It helps.