Null exception on nested JSON object

Question

I'm using Newtonsoft to deserialize an array of JSON objects. I'm able to successfully deserialize the entire object with the exception of the fully nested @attributes objects.

Here is a snippet of an item I'm trying to parse:

"item" : [{
"title" : "Bloody.Birthday.1981.1080p.BluRay.X264-7SinS",
"guid" : "https:\/\/api.nzb.su\/details\/35e799ce66c3290db629b68e3bac20f9",
"link" : "https://",
"comments" : "https://url",
"pubDate" : "Wed, 25 Jun 2014 12:47:16 -0400",
"category" : "Movies > HD",
"description" : "Bloody.Birthday.1981.1080p.BluRay.X264-7SinS",
"enclosure" : {
    "@attributes" : {
        "url" : "https://url",
        "length" : "6777211483",
        "type" : "application\/x-nzb"
    }
},
"attr" : [{
        "@attributes" : {
            "name" : "category",
            "value" : "2000"
        }
    }, {
        "@attributes" : {
            "name" : "category",
            "value" : "2040"
        }
    }, {
        "@attributes" : {
            "name" : "size",
            "value" : "6777211483"
        }
    }
  ]
 }
]

Here are my classes to drill down and populate the items:

public class item
{
    public string title { get; set; }
    public string pubDate { get; set; }
    public IList<Attr> attr { get; set; }
}

public class Attr
{

    public Attributes attribs { get; set; }
}


public class Attributes
{
    public string name { get; set; }
    public string value { get; set; }

}

When do I a count on the item.attr, I get the proper # but if I try to actually get the name/value of the Attributes in the list, it gives me a null error. I've done a lot of research and have been unable to determine why it's creating the appropriate items in the List but not the values within the item.

Any thoughts?

So you are expecting us to guess your code and find the bug? — L.B, Jun 26 '14 at 20:39
possible duplicate of [What is a NullReferenceException and how do I fix it?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — Daniel Kelley, Jun 27 '14 at 14:45
@DanielKelley No duplicate IMO. Here, the OP knows what the exception is about but just can't figure out *why* he's getting it. — Gert Arnold, Jun 28 '14 at 21:02

score 0 · Accepted Answer · answered Jun 26 '14 at 20:48

0

Since @attributes is not a valid property name in C#, you need to use a [JsonProperty] attribute to map it to the JSON, e.g.:

public class Attr
{
    [JsonProperty("@attributes")]
    public Attributes attribs { get; set; }
}

answered Jun 26 '14 at 20:48

Brian Rogers

125,747
31
299
300

Null exception on nested JSON object

1 Answers1