System.Net.WebException : The remote server returned an error: (415) UNSUPPORTED MEDIA TYPE

I am having problems with a bit of code that accesses a restful web service. Running this code, it errors out at var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse(); and the exception returned is: "System.Net.WebException : The remote server returned an error: (415) UNSUPPORTED MEDIA TYPE."

public bool CreateAccount(string myUsername, string url, string authtoken) {
try {
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
httpWebRequest.ContentType = "application/json";
httpWebRequest.MediaType="application/json";
httpWebRequest.Accept="application/json";
httpWebRequest.Method = "POST";

WebHeaderCollection headers = new WebHeaderCollection();
headers.Add("Authorization: Token"+authtoken);
httpWebRequest.Headers = headers;

using (StreamWriter streamWriter = new StreamWriter(httpWebRequest.GetRequestStream())) {
streamWriter.Write("{username : '"+myUsername+"'}");
}

var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse(); // Fails on this line.
using (var streamReader = new StreamReader(httpResponse.GetResponseStream())) {
JavaScriptSerializer jsSerializer = new JavaScriptSerializer();
string json = streamReader.ReadToEnd();
}
return true;

} catch (WebException e) {
throw e;
return false;
}
//return true;
}

I have tried various things for the ContentType, MediaType, and Accept, but the working example given to me by the developer of the service supplies -H "Content-Type: application/json" to curl, so it would seem that "application/json" is the correct value. He also does --data-binary, which I assume streamWriter does for me.

Does anyone know what might be causing this error?

Figured it out.

When I do:

WebHeaderCollection headers = new WebHeaderCollection();
headers.Add("Authorization: Token "+authtoken);
httpWebRequest.Headers = headers;

I accidentally blow away all of the existing headers that were created by doing:

httpWebRequest.ContentType = "application/json";
httpWebRequest.MediaType="application/json";
httpWebRequest.Accept="application/json";
httpWebRequest.Method = "POST";

The answer is to move the code where I create the header with the auth token above the code where I set the other headers.

来源