Convert List<string> to JSON using C# and Newtonsoft

Question

I have a List that I would like to convert to JSON using C# and Newtonsoft.

tags

[0]: "foo"
[1]: "bar"

Output to be:-

{"tags": ["foo", "bar"]}

Can anybody point me in the right direction please? I can convert the List to JSON okay but they key thing here is I need the "tags" part in the JSON which I do not get with a convert using JsonConvert.SerializeObject(tags).

Answer 1

Arguably the easiest way to do this is to just write a wrapper object with your List<string> property

public class Wrapper
{
    [JsonProperty("tags")]
    public List<string> Tags {get; set; }
}

And then when serialized this gives the output you expect.

var obj = new Wrapper(){ Tags = new List<string>(){ "foo", "bar"} };
var json = JsonConvert.SerializeObject(obj);
Console.WriteLine(json);
// outputs: {"tags":["foo","bar"]}

Live example: http://rextester.com/FTFIBT36362

Answer 2

Use like this.

var data = new { tags = new List<string> { "foo", "bar" } };
var str = Newtonsoft.Json.JsonConvert.SerializeObject(data);

Output:

{"tags": ["foo","bar"] }

Hope this helps.

Answer 3

Create a separate class like this:

public class TagList
{
    [JsonProperty("tags")]
    List<string> Tags { get; set; }

    public TagList(params string[] tags)
    {
        Tags = tags.ToList();
    }
}

Then call:

JsonConvert.SerializeObject(new TagList("Foo", "Bar"));

Answer 4

You can use anonymous object to wrap your list like that:

JsonConvert.SerializeObject(new {Tags = tags});

Answer 5

You could use this.

static void  Main(string[] args)
    {
        List<string> messages = new List<string>();
        messages.Add("test");
        messages.Add("test 2");
        Items data = new Items { items = messages };
        string output = JsonConvert.SerializeObject(data);
        JObject jo = JObject.Parse(output);
        Console.WriteLine(jo);
    }

public class Items
{
   public List<string> items { get; set; }
}

Produces:

{
  "items": [
    "test",
    "test 2"
  ]
}