How to parse / deserialize JSON returned from rest service in C#

.net, c#, json, json-deserialization, rest

Solution

The classes into which you're deserializing are incorrect. You are missing the "Patients" class.

When I have JSON and am trying to deserialize it I like to use http://json2csharp.com to generate a first cut at the deserialization classes. It's more accurate than trying to do it by hand.

var jsonobject = JsonConvert.DeserializeObject<RootObject>(json);

public class Patient
{
    public string patientid { get; set; }
    public string name { get; set; }
    public string status { get; set; }
    public string start { get; set; }
    public string last { get; set; }
    public string engagement { get; set; }
    public string drug { get; set; }
    public string adherence { get; set; }
    public string vitals { get; set; }
    public string last_appointment { get; set; }
    public string next_appointment { get; set; }
}

public class Patients
{
    public List<Patient> patient { get; set; }
}

public class Pathway
{
    public Patients patients { get; set; }
}

public class RootObject
{
    public Pathway pathway { get; set; }
}

P.S. The exception you were getting is usually a really good clue that there's something wrong with the way you've defined the deserialization classes.

Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[ConsoleApplication1.Program+patient]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.

To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.

Problem

I am getting JSON in string format from a URL whose structure is like this, but I am unable to parse it. It's throwing an exception, any idea how to parse it? Here is the structure: ``` { "pathway":{ "patients":{ "patient":[ { "patientid":"7703176", "name":"Abbot, Bud", "status":"Invited", "start":"2013-12-07", "last":"N/A", "engagement":"N/A", "drug":"N/A", "adherence":"N/A", "vitals":"Current", "last_appointment":"2013-10-25", "next_appointment":"None" }, { "patientid":"5089554", "name":"Brennan, Bonnie", "status":"Connected", "start":"2013-12-29", "last":"2014-02-01", "engagement":"Low", "drug":" ", "adherence":" ", "vitals":"Out of Date", "last_appointment":"2013-04-21", "next_appointment":"None" } ] } } } ``` i am doing like this: ``` public class PathWayWrapper { public pathway pathway { get; set; } } ``` and ``` public class pathway { public List<patient> patients { get; set; } } ``` and ``` public class patient { public long patientid { get; set; } public string name { get; set; } public string status { get; set; } public string start { get; set; } public string last { get; set; } public string engagement { get; set; } public string drug { get; set; } public string adherence { get; set; } public string vitals { get; set; } public string last_appointment { get; set; } public string next_appointment { get; set; } } ``` here is my parsing code: ``` StreamReader reader = new StreamReader(response.GetResponseStream()); string json = reader.ReadToEnd(); var Jsonobject = JsonConvert.DeserializeObject<PathWayWrapper>(json); objPathway = Jsonobject.pathway; ```

Original source