Expecting element 'root' from namespace ''.. Encountered 'None' with name '', namespace ''

Question

I've been searching for the past 4 hours for ways on how to tackle this problem, and I've not yet found a solution.

I'm building an API with .NET and wish to parse JSON information that is sent back from API calls.

My current approach does the following:

private void PostNewPlayer(HttpContext context)
{
    // Create the serializer
    context.Request.InputStream.Position = 0;

    DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(ASPlayer));
    ASPlayer p = (ASPlayer)json.ReadObject(context.Request.InputStream);  <-- Exception here
    Int32 playerId = ASPlayerManager.InsertNewPlayer(p);
}

But I currently get an Exception at the indicated line. I have made sure my class implements the correct serialization namespaces:

using System.Runtime.Serialization;
using System.IO;
using System.Runtime.Serialization.Json;

The class I am trying to serialize has had its DataContract and Member fields set accordingly:

[DataContract]
public class ASPlayer
{
    [DataMember]
    private string _name;
    public string player_name 
    {
        get { return _name; }
        set { _name = value; }
    }

    [DataMember]
    private string _location;
    public string player_location
    {
       get { return _location; }
       set { _location = value; }
    }

    // Other vars
    ... 

    public ASPlayer(string name, string location)
    {
        _name = name;
        _location = location;
     }
}

However, when I use a HTTP client such as Postman to make a request I get the error stated in the question title

Solution 1

The answer was a very bad mistake on my behalf, but for those who encounter this in future make sure you send your JSON object in Postman through the Raw field. In my case I simply did:

{
  "player_name": "Test",
  "player_location": "EUW",
  "player_wins":10,
  "player_draws":10,
  "player_losses":15,
  "player_points":20
}

This fixed it

Solution 2

I think you marked the wrong variables, this:

[DataMember]
private string _name;
public string player_name 

should be this:

private string _name;
[DataMember]
public string player_name 

Comments

[Halfpint]

Hey. Thanks for the suggestion. I tried marking the variables both ways and still no luck :( any other ideas?

[thumbmunkeys]

It would help if you post your JSON

[Halfpint]

I think I've just spotted what I've done wrong. Im sending the parameters in the header, I should be posting a json object. Oops!

[dbc]

@thumbmunkeys - ordering is only important for DataContractSerializer. DataContractJsonSerializer ignores property order since JSON object properties are defined to be unordered.