POST string to ASP.NET Web Api application - retur

Question

Im trying to transmit a string from client to ASP.NET MVC4 application.

But I can not receive the string, either it is null or the post method can not be found (404 error)

Client Code to transmit the string (Console Application):

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://localhost:49032/api/test");
request.Credentials = new NetworkCredential("user", "pw");
request.Method = "POST";
string postData = "Short test...";
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = byteArray.Length;

Stream dataStream = request.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();

WebResponse response = request.GetResponse();
Console.WriteLine(((HttpWebResponse)response).StatusDescription);
dataStream = response.GetResponseStream();

StreamReader reader = new StreamReader(dataStream);
string responseFromServer = reader.ReadToEnd();
Console.WriteLine(responseFromServer);
reader.Close();
dataStream.Close();
response.Close();
Console.ReadLine();

ASP.NET Web Api Controller:

public class TestController : ApiController
{
    [Authorize]
    public String Post(byte[] value)
    {
        return value.Length.ToString();
    }
}

In that case I'm able to call the "Post" method, but "value" is NULL. If I change the method signature to (string value) than it will never called.

Even "without" the [Authorize] setting it has the same strange behavior. -> So it has nothing to do with the user authentication.

Any ideas what I'm doing wrong? I'm grateful for any help.

Answer 1

Darrel is of course right on with his response. One thing to add is that the reason why attempting to bind to a body containing a single token like "hello".

is that it isn’t quite URL form encoded data. By adding “=” in front like this:

=hello

it becomes a URL form encoding of a single key value pair with an empty name and value of “hello”.

However, a better solution is to use application/json when uploading a string:

POST /api/sample HTTP/1.1
Content-Type: application/json; charset=utf-8
Host: host:8080
Content-Length: 7

"Hello"

Using HttpClient you can do it as follows:

HttpClient client = new HttpClient();
HttpResponseMessage response = await client.PostAsJsonAsync(_baseAddress + "api/json", "Hello");
string result = await response.Content.ReadAsStringAsync();
Console.WriteLine(result);

Henrik