Returning XML from web API c#

Question

newbie here as long as web API is concerned.

web Api:

[HttpGet]
    public IHttpActionResult Test()
    {
        var doc = new XmlDocument();
        XmlElement tournament = (XmlElement)doc.AppendChild(doc.CreateElement("Tournament"));
        XmlElement match = (XmlElement)tournament.AppendChild(doc.CreateElement("Match"));
        match.SetAttribute("ID", "SomeMatch");

        return Ok(doc.InnerXml);
    }

Result:

<string xmlns="http://schemas.microsoft.com/2003/10/Serialization/">&lt;Tournament&gt;&lt;Match ID="SomeMatch" /&gt;&lt;/Tournament&gt;</string>

Two problems:

1. why it is wrapped in this string element when my XML does not have it?
2. why < is converted to "& lt;" and > to "& gt;"

and how to get back just

<Tournament>
<Match ID="SomeMatch" /></Tournament>

Answer 1

Since you are returning a string from the action, ASP.Net Web API is creating the equivalent XML to represent a string.

Now, if you were to ensure that API uses XML serialization, client can add accept header to the request. Alternatively, you can specify the formatter either the way you have or in the action itself by returning Content using following constructor:

return Content (HttpStatusCodeHere, doc.DocumentElement, Configuration.Formatters.XmlFormatter)

Note that I do not have access to Visual Studio so class/property names might not be accurate.

Answer 2

You have to returns doc.DocumentElement instead of doc.InnerXml.

Because doc.InnerXml gives you xml in string format that's why your xml is shown in <string> format

[HttpGet]
        public IHttpActionResult Test()
        {
            var doc = new XmlDocument();
            XmlElement tournament = (XmlElement)doc.AppendChild(doc.CreateElement("Tournament"));
            XmlElement match = (XmlElement)tournament.AppendChild(doc.CreateElement("Match"));
            match.SetAttribute("ID", "SomeMatch");
            return Ok(doc.DocumentElement);                 
        }

All your api(s) returns output is in xml format because your HttpConfiguration set in XmlFormatter by default.