在 C# UWP 中从 PHP 解析 Json_encoded 数组

Question

I developing a UWP app using C#, this conect a PHP WebService, this web service return a array encoded using json_encode function, i cant parse this json string in my UWP app, please help

1: PHP CODE

$aCli[]=  array("CAT"=>"OK","MSG"=>"SESION-OK","EXTRA"=>array("ID"=>"$spID","NOM"=>"$spNom"));
echo json_encode($aCli);

2: The result using postman is:

[{"CAT":"OK","MSG":"SESION-OK","EXTRA":{"ID":"3","NOM":"CHARLS"}}]

3. The result using Async Task from C# is:

"[{\"CAT\":\"OK\",\"MSG\":\"SESION-OK\",\"EXTRA\":{\"ID\":\"3\",\"NOM\":\"CHARLS\"}}]"

4. How to deserialize this string?, i am trying it using

using Windows.Data.Json;

5. This is the code using in this time

sJSON= await IniciarSesion();//this use async class to connect with webservice
JsonObject objJson = JsonObject.Parse(sJSON);//error is raised in this line
/*Json String is invalid*/
sCat = objJson["CAT"].GetString();
sMsg = objJson["MSG"].GetString();

Answer 1

Important comment above:

your JSON is a representation of an array, not an object.

IF you can use Newtonsoft (JSON.Net) , here's one way, with dependency on JSON.Net , not Windows.Data.Json . Trivial sample only, improve as necessary (null checks, etc.)

using System;
using Newtonsoft.Json.Linq;

public class Program
{
    public static void Main()
    {
        var str = "[{\"CAT\":\"OK\",\"MSG\":\"SESION-OK\",\"EXTRA\":{\"ID\":\"3\",\"NOM\":\"CHARLS\"}}]";
        var j = JArray.Parse(str);
        var token = j[0];

        //using dynamic to simplify sample, create/use your own type
        var obj = token.ToObject<dynamic>(); 

        Console.WriteLine(obj.CAT);
        Console.WriteLine(obj.MSG);
        Console.WriteLine(obj.EXTRA);
        Console.WriteLine(obj.EXTRA.ID);
        Console.WriteLine(obj.EXTRA.NOM);
    }
}

Hth..

Answer 2

You could use Newtonsoft to deserialize JSON string directly. For your requirement, you need to make the data model fist.

[{"CAT":"OK","MSG":"SESION-OK","EXTRA":{"ID":"3","NOM":"CHARLS"}}]

public class Pet
{
    public string Cat { get; set; }
    public string Msg { get; set; }
    public Extra Extra { get; set; }
}

public class Extra
{
    public string Id { get; set; }
    public string Nom { get; set; }
}

Usage

private void Button_Click(object sender, RoutedEventArgs e)
{
    var str = "[{\"CAT\":\"OK\",\"MSG\":\"SESION-OK\",\"EXTRA\":{\"ID\":\"3\",\"NOM\":\"CHARLS\"}}]";
    var items = JsonConvert.DeserializeObject<List<Pet>>(str);
}

For more you could refer Serializing and Deserializing JSON documentation.

Answer 3

The problem is with the brackets ' [] ' at the beginning and end of the string,

You should trim them like:

' YOUR_JSON_STRING = YOUR_JSON_STRING.trim('[',']');

and then parse the json string below:

' dynamic result = JsonConvert.DeserializeObject(YOUR_JSON_STRING)'