https request with HttpClient

Question

Hello,

i try to develop a Client(WindowsPhone8.1) Server Connection that used a SSL certificate. But it is not working. (statuscode 404)

If i use my Browser as a Client, it runs perfectly.

here the code:

//OnLaunched

try{
                // Read the contents of the Certificate file
                Uri certificateFile = new Uri("ms-appx:///Assets/TestSignedByCA.cer");
                Windows.Storage.StorageFile file = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(certificateFile);
                Windows.Storage.Streams.IBuffer certBlob = await Windows.Storage.FileIO.ReadBufferAsync(file);


                // Create an instance of the Certificate class using the retrieved certificate blob contents
                Windows.Security.Cryptography.Certificates.Certificate rootCert = new Windows.Security.Cryptography.Certificates.Certificate(certBlob);


                // Get access to the TrustedRootCertificationAuthorities for your own app (not the system one)
                Windows.Security.Cryptography.Certificates.CertificateStore trustedStore = Windows.Security.Cryptography.Certificates.CertificateStores.TrustedRootCertificationAuthorities;


                // Add the certificate to the TrustedRootCertificationAuthorities store for your app
                trustedStore.Add(rootCert);
            }
            catch (Exception oEx)
            {
                // Catch and report exceptions
                System.Diagnostics.Debug.WriteLine("Exceptionng cert: " + oEx.Message);
            }



//On click a button

HttpClientHandler aHandler = new HttpClientHandler();
//aHandler.ClientCertificateOptions = ClientCertificateOption.Automatic; -test


            using (HttpClient client = new HttpClient(aHandler))
            {
                client.BaseAddress = new Uri("https://127.0.0.1:4712/");
                StringContent content = new StringContent("hallo, ich bin eine App!");
                HttpResponseMessage response = await client.PostAsync("index/", content);
            }

I hope some one can help me ...

and sry for my bad english