DataContractJsonSerializer用于反序列化JSON

Question

I have a Json string which looks like below,

{
    "ErrorDetails":null,
    "Success":true,
    "Records":[
                {
                "Attributes":[
                                {
                                    "Name":"accountid",
                                    "Value":null
                                },
                                {
                                    "Name":"accountidname",
                                    "Value":null
                                }
                ],
                "Id":"9c5071f7-e4a3-e111-b4cc-1cc1de6e4b49",
                "Type":"contact"
                }
    ]
}

I'm using following to deserialize this string,

DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(typeof(JSONPackage));
object objResponse = jsonSerializer.ReadObject(response.GetResponseStream());
JSONPackage jsonResponse = objResponse as JSONPackage;

And my JSONPackage looks like following,

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CommonLibs.JSONObjects
{
    public class JSONPackage
    {
        public string ErrorDetails { get; set; }
        public string Success { get; set; }
        public List<Record> Records { get; set; }
    }
}

And Records looks like this,

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Threading.Tasks;

namespace CommonLibs.JSONObjects
{
    public class Record
    {
        public List<Attributes> Attributes { get; set; }
        public string Id { get; set; }
        public string Type { get; set; }
    }
}

Attributes looks like,

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Threading.Tasks;

namespace CommonLibs.JSONObjects
{
    public class Attributes
    {
        public AttributeItem AttributeItem { get; set; }
    }
}

And lastly AttributeItem looks like the following,

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Threading.Tasks;

namespace CommonLibs.JSONObjects
{
    public class AttributeItem
    {
        public string Name { get; set; }
        public string Value { get; set; }
    }
}

However, this doesn't seems to work.

when I do,

Console.WriteLine(jp.Records[0].Attributes[0].AttributeItem.Name);

I get a NullPointerException ( jp is a JSONPackage Object).

But, if I do,

Console.WriteLine(jp.Records[0].Attributes.Count) i get "2"

Can you please assist?

Answer 1

You don't need the Attributes class.

Change

public List<Attributes> Attributes { get; set; }

to

public List<AttributeItem> Attributes { get; set; }