How to read json data in C#

Question

4.00/5 (1 vote)

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I am new to json and am trying to write code to import a file which looks like the following:
<pre lang="xml">
{
 "name": "John", 
 "joined": "2010/5/4 21:57:34", 
 "title": "Area Manager",
 "languages": [{"id":1,"name":"C#"},{"id":2,"name":"VB.NET"}],

 "speaks":
   [
    {"id":5,"language":"English"},
    {"id":6,"language":"French"}
   ],
 "products":
   [
    {"product_id":"36847f8001cd1","name":"Bolt Free"},
    {"product_id":"36847f8001cd7","name":"Oil4All"}
   ],
 "areas":
   {"countries":
      [
        {"iso_3166_1":"US", "release_date":"1997-02-13"},
        {"iso_3166_1":"DE", "release_date":"1997-05-21"},
      ]
   }
}

Using NuGet I have installed the Newton.Json package. The code to read the file looks like this:

C#

using (System.IO.StreamReader r = new System.IO.StreamReader(src))
{
    string json = r.ReadToEnd();
                EmployeeInfo item = Newtonsoft.Json.JsonConvert.DeserializeObject<EmployeeInfo>(json);
}

The Item class is defined as follows:

C#

public class EmployeeInfo
{
    public string name;
    public DateTime joined;
    public String title;
    public List<Languages> languages;
    public List<Speaks> speaks;
    public List<Products> products;
    public List<Areas> areas;

    public class Languages
    {
        public int id;
        public String name;
    }

    public class Speaks
    {
        public int id;
        public String language;
    }

    public class Products
    {
        public String product_id;
        public String name;
    }

    public class Areas
    {
        public String iso_3166_1;
        public DateTime release_date;
    }
}

When I run the code I get an unhandled exception which says:
“Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[WindowsFormApp.EmployeeInfo+Areas]' 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<T>) 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.”
Can anyone tell me what I am doing wrong and how to get the last item deserialized correctly?
Thanks in advance.

Posted 26-May-14 3:09am

Kevin Derrick Murphy

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5 solutions

Solution 2

convert it into dataset like this and then you can easily get data from dataset.. :)

How to Convert JSON String into Dataset using c#[^]

Posted 26-May-14 3:19am

Nirav Prabtani

Comments

Kevin Derrick Murphy 26-May-14 9:32am

Thanks, I will have a look.

Nirav Prabtani 26-May-14 10:09am

welcome.. :)

Solution 3

Hi...
http://stackoverflow.com/questions/4109807/parsing-json-data-with-c-sharp[^]
http://stackoverflow.com/questions/2246694/how-to-convert-json-object-to-custom-c-sharp-object[^]
Thank u.

Posted 26-May-14 3:28am

Murali0195

Comments

Kevin Derrick Murphy 26-May-14 9:32am

Thanks, I will have a look.

Solution 5

you can use http://json2csharp.com/[^] to generate the clases from the json. for example below is the result for your json.

C#

public class Language
{
    public int id { get; set; }
    public string name { get; set; }
}

public class Speak
{
    public int id { get; set; }
    public string language { get; set; }
}

public class Product
{
    public string product_id { get; set; }
    public string name { get; set; }
}

public class Country
{
    public string iso_3166_1 { get; set; }
    public string release_date { get; set; }
}

public class Areas
{
    public List<country> countries { get; set; }
}

public class RootObject
{
    public string name { get; set; }
    public string joined { get; set; }
    public string title { get; set; }
    public List<language> languages { get; set; }
    public List<speak> speaks { get; set; }
    public List<product> products { get; set; }
    public Areas areas { get; set; }
}

Note that you need to change the date time type in generated code. so the final classes will be.

C#

public class Language
{
    public int id { get; set; }
    public string name { get; set; }
}

public class Speak
{
    public int id { get; set; }
    public string language { get; set; }
}

public class Product
{
    public string product_id { get; set; }
    public string name { get; set; }
}

public class Country
{
    public string iso_3166_1 { get; set; }
    public DateTime release_date { get; set; }
}

public class Areas
{
    public List<country> countries { get; set; }
}

public class RootObject
{
    public string name { get; set; }
    public DateTime joined { get; set; }
    public string title { get; set; }
    public List<language> languages { get; set; }
    public List<speak> speaks { get; set; }
    public List<product> products { get; set; }
    public Areas areas { get; set; }
}

Now you can convert json to object like below

C#

RootObject item = Newtonsoft.Json.JsonConvert.DeserializeObject<rootobject>(json);

Posted 26-May-14 7:05am

DamithSL

Updated 26-May-14 7:06am

v2

Comments

Kevin Derrick Murphy 26-May-14 14:01pm

Thanks for that. Could be very useful.

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Mehdi Gholam · Accepted Answer · 2014-05-26T03:17:00

areas is an object with a property countries which is an array of string and date so you should add

C#

public class arr 
{
        public String iso_3166_1;
        public DateTime release_date;
}

public class Areas
{
    public List<arr> countries;
}


// and your type is 
public class EmployeeInfo
{
    public string name;
    public DateTime joined;
    public String title;
    public List<languages> languages;
    public List<speaks> speaks;
    public List<products> products; 
    public Areas areas;
}
</products></speaks></languages>

Vi(ky · Accepted Answer · 2014-05-26T04:07:00

Solution 4

C#

JavaScriptSerializer JsonSerializer = new JavaScriptSerializer();
EmployeeInfo OEmployeeInfo = JsonSerializer.Deserialize<EmployeeInfo>(JsonString);
return OEmployeeInfo;
</customformula>

Posted 26-May-14 4:07am

Vi(ky

v2

How to read json data in C#

5 solutions

Solution 1

Solution 2

Solution 3

Solution 5

Solution 4

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