HttpWebRequest "POST" returning server error (Exception) - silverlight

Question

I'm trying to call the google URL shortner API from a WP7 app, I tried first on a Console Application by doing this:
var httpWebRequest = (HttpWebRequest)WebRequest.Create("https://www.googleapis.com/urlshortener/v1/url");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "POST";
using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
string json = "{\"longUrl\":\"http://www.google.com/\"}";
Console.WriteLine(json);
streamWriter.Write(json);
}
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var responseText = streamReader.ReadToEnd();
Console.WriteLine(responseText);
}
Console.Read();
and it worked fine, and returned everything OK, but when I try to do it on a Windows Phone App like this:
private void button1_Click(object sender, RoutedEventArgs e)
{
testConnection();
}
private void testConnection()
{
if (!NetworkInterface.GetIsNetworkAvailable())
MessageBox.Show("There's no internet connection, please reconnect to the internet and try again");
else
{
var req = (HttpWebRequest)WebRequest.Create("https://www.googleapis.com/urlshortener/v1/url");
req.ContentType = "application/json";
req.Method = "POST";
req.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), req);
textBlock2.Text = "Done";
}
}
void GetRequestStreamCallback(IAsyncResult asynchronousResult)
{
HttpWebRequest webRequest = (HttpWebRequest)asynchronousResult.AsyncState;
// End the stream request operation
Stream postStream = webRequest.EndGetRequestStream(asynchronousResult);
// Create the post data
// Demo POST data:
string postData = "http://www.google.com";
byte[] byteArray = Encoding.Unicode.GetBytes(postData);
// Add the post data to the web request
postStream.Write(byteArray, 0, byteArray.Length);
postStream.Close();
// Start the web request
webRequest.BeginGetResponse(new AsyncCallback(GetResponseCallback), webRequest);
}
void GetResponseCallback(IAsyncResult asynchronousResult)
{
try
{
HttpWebRequest webRequest = (HttpWebRequest)asynchronousResult.AsyncState;
HttpWebResponse response;
// End the get response operation
response = (HttpWebResponse)webRequest.EndGetResponse(asynchronousResult);
Stream streamResponse = response.GetResponseStream();
StreamReader streamReader = new StreamReader(streamResponse);
textBlock1.Text= streamReader.ReadToEnd();
streamResponse.Close();
streamReader.Close();
response.Close();
}
catch (WebException e)
{
}
}
The code always goes to the catch of the try method and gives "not found" error.

Answer 1

There is a known issue with SSL and not-trusted certificates. Connection to a web site with SSL that require ClientCertificates is not supported in the current Windows Phone 7 application model (Only BasicAuthentication is supported). You can read about the same problem here: http://forums.create.msdn.com/forums/p/65076/398730.aspx

Answer 2

I had a similar issue (which makes sense since I started out with this code as my example...) and when I changed the following code it started working to the point where I could progress forward again.
... from:
byte[] byteArray = Encoding.Unicode.GetBytes(postData);
... to (the equivalent of):
byte[] byteArray = Encoding.UTF8.GetBytes(postData);