Json Navigation

Question

I am getting a string from a Rest API. The string contains a list of orders.

string result = await content.ReadAsStringAsync();
dynamic json = JsonConvert.DeserializeObject(result);
string res = json[0]["id"];
MessageBox.Show( res.ToString());

I can see the individual order IDs but I need to get all order IDs. Then I have to process each order ID separately. I may need a loop or some other mechanism. Can anybody help?

Answer 1

Hello @Muhammad Ahmed

The best path is to deserialize to a list which allows you to have better control such as using a for/next or the ability to use linq to find information. Below shows using a class to read the data while the other uses a slight variation of what you presented. If these do not work for you let me know why/

Example using Newtonsoft.Json

Json (with minimal information)

[  
    {  
        "id": 1,  
        "customerId": 100  
    },  
    {  
        "id": 2,  
        "customerId": 234  
    },  
    {  
        "id": 3,  
        "customerId": 300  
    },  
    {  
        "id": 4,  
        "customerId": 234  
    }  
]  

Class to contain above data.

public class Order  
{  
    public int id { get; set; }  
    public int customerId { get; set; }  
}  

Deserialize

using System;  
using System.Collections.Generic;  
using System.IO;  
using System.Linq;  
using System.Text;  
using System.Threading.Tasks;  
using JsonSampleLibrary.Classes;  
using Newtonsoft.Json;  
  
namespace JsonSampleLibrary  
{  
    public class DynamicOperations  
    {  
        public static List<Order> ReadOrdersStrongTyped(string fileName)  
        {  
            return JsonConvert.DeserializeObject<List<Order>>(File.ReadAllText(fileName));  
        }  
    }  
}  

Work with the deserialized data first traversing all then using lambda to get orders for a specific customer.

var ordersList = DynamicOperations.ReadOrdersStrongTyped("orders.json");  
  
for (int index = 0; index < ordersList.Count; index++)  
{  
    Console.WriteLine(ordersList[index].id);  
}  
  
Console.WriteLine();  
  
var id = 234;  
  
var specificOrder = ordersList.Where(order => order.customerId == id).ToList();  
  
for (int index = 0; index < specificOrder.Count(); index++)  
{  
    Console.WriteLine(specificOrder[index].id);  
}  

Then the other way is with no class similar to what you have.

using System;  
using System.Collections.Generic;  
using System.IO;  
using System.Linq;  
using System.Text;  
using System.Threading.Tasks;  
using JsonSampleLibrary.Classes;  
using Newtonsoft.Json;  
  
namespace JsonSampleLibrary  
{  
    public class DynamicOperations  
    {  
        public static void ReadOrders1(string fileName)  
        {  
            var jsonString = File.ReadAllText(fileName);  
            var objects = JsonConvert.DeserializeObject<dynamic>(jsonString);  
            foreach (var o in objects)  
            {  
                Console.WriteLine($"{o.id}");  
            }  
        }  
  
    }  
}  

In the above o.id is known as an integer e.g. testing the type

foreach (var o in objects)  
{  
    JValue id = o.id;  
    Console.WriteLine($"{id.Type}");  
}  

And typing id column

public static void ReadOrders1A(string fileName)  
{  
    var jsonString = File.ReadAllText(fileName);  
    var objects = JsonConvert.DeserializeObject<dynamic>(jsonString);  
    List<int> identifiers = new List<int>();  
    foreach (var o in objects)  
    {  
        identifiers.Add(Convert.ToInt32(o.id));  
    }  
}