Convert string to json array in C#

Question

I am new to C#. I want to convert the two strings to single JSON array.
I tried the following:

var username = "username";
var password = "XXXXXXXX";
var json_data = "result":[{"username":username,"password":password}]'; //To convert the string to Json array i tried like this
MessageBox.Show(json_data);

It is not working, I'm getting a lot of errors.

I've went through the following links:

http://json.codeplex.com/

Convert string to Json Array

http://www.codeproject.com/Articles/272335/JSON-Serialization-and-Deserialization-in-ASP-NET

convert string to json

To learn how to convert my string to Json array. Well explained in the above url, but for my case I don't know how to convert this two string to single Json array.

I want the output to be like this format,

[{"result":{"username":"Tom","password":"XXXXXXX"}}]

Please help me in doing this.

Answer 1

You can use a JSON serialiser API. A commonly used one is the one from Newtonsoft, called Json.NET.

Job of such an API is to convert C# objects to JSON (also known as serialisation) and convert JSON data into C# objects (deserialisation).

In your example, Newtonsoft JSON API can be used as follows.

public class UserData { public string username; public string password; }

var userData = new UserData() { username = "Tom", password = "XXXXXXXX" };

UserData[] arr = new UserData[] { userData };

string json_data = JsonConvert.SerializeObject(arr); // this is the Newtonsoft API method

// json_data will contain properly formatted Json. Something like [{"result":{"username":"Tom","password":"XXXXXXX"}}] 

MessageBox.Show(json_data); 

Excuse my typing as I'm doing it over phone.

Answer 2

To extend bytefire's answer, there are a couple of ways this can be achieved:

1. Create a class with the desired properties, in your case username and password. I will annotate the properties with JsonProperty from Json.NET so the serializer can match them disregarding lower/uppercase:

   public class User
   {
      [JsonProperty(PropertName = username)]
      public string Username { get; set; }
   
      [JsonProperty(PropertName = password)]
      public string Password { get; set; }
   }
   

Then, serialize your object using JsonConvert.SerializeObject:

var user = new User { Username = "user", Password = "pass" };
var jsonUser = JsonConvert.SerializeObject(user);

1. Using JsonTextWriter from Json.NET, you can construct a json without creating an object:

   var stringBuilder = new StringBuilder();
   var stringWriter = new StringWriter(stringBuilder);
   string jsonString = null;
   
   using (var jsonWriter = new JsonTextWriter(stringWriter))
   {
      writer.Formatting = Formatting.Indented;
      writer.WriteStartObject();
      writer.WriterPropertyName("username");
      writer.WritePropertyValue("user");
      writer.WriterPropertyName("password");
      writer.WritePropertyValue("pass");
      writer.WriteEnd();
      writer.WriteEndObject();
      jsonString = writer.ToString();
   }
   

Answer 3

Or one of many alternatives: simple Json, if you think JSON.net is way too huge.

Answer 4

In Javascript Object Notation the top level is always an object.

In JSON an array is not an object but it can be a value.

You can unfold the grammer into this:

{ string : [ { string : string , string : string },{ string : string , string : string } ] }

in your case this could be:

{ "allUsers": [ { "name": "Luis" , "password": "R0Cke+" }, { "name": "Janette" , "password": "BookTour2011" } ] }

Answer 5

Simplest way I came across. It worked for me when I wanted to parse a JSON i get from YelpAPI.

1. Paste JSON as classes in your visual studio or another IDE
2. Request the API and get the JSON content in var contentJSON.

3. T here from is one of the classes whose list you would like to make while value 1 exact string used in JSON file .

   var contentJson = await SendRequest(request);

   dynamic response = JsonConvert.DeserializeObject(contentJson);

   List abc = response.value1.ToObject>();

Note : T and value1 are the same in JSON but when we paste JSON as classes, we get T class and value1 as parent value in JSON tree. Code: