Question

I´m trying to use a Webservice in a .Net Compact Framework 3.5 Project which has no WSDL and where I have to use HttpWebRequest.
I´ve tried my code on 2 Devices and on the Emulator but I get everytime the same Exception and I really don´t get why!?

First, my code:

internal void SendSms()
    {
        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(@"https://username:[e-mail]/RPC2");
        req.Method = @"POST";
        req.ContentType = @"text/xml";
        req.ContentLength = Body.Length;
        using (Stream stream = req.GetRequestStream())
        using (StreamWriter writer = new StreamWriter(stream, Encoding.UTF8))
        {
            writer.Write(Body);
        }
        using (Stream responseStream = req.GetResponse().GetResponseStream())
        using (StreamReader reader = new StreamReader(responseStream, Encoding.UTF8))
        {
            string result = reader.ReadToEnd();
        }
    }

In line “using (Stream stream = req.GetRequestStream())” I get the following exception and I can´t figure out why:

System.Net.WebException
{“Could not establish connection to network.”}

Stacktrace:

at System.Net.HttpWebRequest.finishGetRequestStream()
at System.Net.HttpWebRequest.GetRequestStream()
at SipMSGate.UI.MainFormController.SendSms()
at SipMSGate.UI.Form1.menuItem1_Click(Object sender, EventArgs e)
at System.Windows.Forms.MenuItem.OnClick(EventArgs e)
at System.Windows.Forms.Menu.ProcessMnuProc(Control ctlThis, WM wm, Int32 wParam, Int32 lParam)
at System.Windows.Forms.Form.WnProc(WM wm, Int32 wParam, Int32 lParam)
at System.Windows.Forms.Control._InternalWnProc(WM wm, Int32 wParam, Int32 lParam)
at Microsoft.AGL.Forms.EVL.EnterMainLoop(IntPtr hwnMain)
at System.Windows.Forms.Application.Run(Form fm)
at SipMSGate.Program.Main()

Status:

System.Net.WebExceptionStatus.ConnectFailure

I can use the Internet explorer on the Devices and on the Emulator, so I think that I have an internet Connection.

Any Idea what´s wrong or what I forget in my code?

Than you so much

twickl

Here is now the complete Code including Yakimych’s Code that gives the xception on 2 Devices and the Emulator Images which all of them are having a connection to the Internet:

using System.Drawing;
using System.IO;
using System.Net;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Windows.Forms;

namespace httpreqTest
{
    public partial class Form1 : Form
    {
        private HttpWebRequest _req;
        private bool _ignoreCertificateErrors;
        private string _errorMessage;
        private const string Body =
        "<?xml version=\"1.0\" encoding=\"UTF-8\"?><methodCall><methodName>samurai.SessionInitiate</methodName><params><param><value><struct><member><name>LocalUri</name><value><string></string></value></member><member><name>RemoteUri</name><value><string>01234556789</string></value></member><member><name>TOS</name><value><string>text</string></value></member><member><name>Content</name><value><string>This is a Test</string></value></member><member><name>Schedule</name><value><string></string></value></member></struct></value></param></params></methodCall>"; 

    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        this._ignoreCertificateErrors = true;
        ASCIIEncoding encoding = new ASCIIEncoding();
        byte[] byte1 = encoding.GetBytes(Body);
        CreateWebRequestObject(@"https://user:[e-mail]/RPC2");
        _req.Method = @"POST";
        _req.ContentType = @"text/xml";
        _req.ContentLength = byte1.Length;
        using (Stream stream = _req.GetRequestStream())
        using (StreamWriter writer = new StreamWriter(stream, Encoding.UTF8))
        {
            writer.Write(Body);
        }
        using (Stream responseStream = _req.GetResponse().GetResponseStream())
        using (StreamReader reader = new StreamReader(responseStream, Encoding.UTF8))
        {
            string result = reader.ReadToEnd();
        }
    }

    public bool CreateWebRequestObject(string Url)
    {
        try
        {
            this._req = (HttpWebRequest)System.Net.WebRequest.Create(Url);
            if (this._ignoreCertificateErrors)
                ServicePointManager.CertificatePolicy = new AcceptAllCertificatePolicy();
        }
        catch (Exception ex)
        {
            this._errorMessage = ex.Message;
            return false;
        }
        return true;
    }

    /// <summary>
    /// Internal object used to allow setting WebRequest.CertificatePolicy to 
    /// not fail on Cert errors
    /// </summary>
    internal class AcceptAllCertificatePolicy : ICertificatePolicy
    {
        public AcceptAllCertificatePolicy()
        {

        }
        public bool CheckValidationResult(ServicePoint sPoint, X509Certificate cert, WebRequest wRequest, int certProb)
        {
            // *** Always accept
            return true;
        }
    }
}

}

Answer 1

You are passing the wrong value to the Content-Length header. It should be the length of the content in bytes not the count of unicode characters in the string (StreamWriter also adds the UTF8 preamble). I recommend not using the preamble and converting the string to a byte array before setting the Content-Length header value. Also, passing the username and password using the req.Credentials property might be a good idea.

internal void SendSms()
{
 HttpWebRequest req = (HttpWebRequest)WebRequest.Create(@"https://api.sipgate.net/RPC2");
 req.Credentials = new NetworkCredential("username", "password");
 req.Method = @"POST";
 req.ContentType = @"text/xml";
 byte[] data = Encoding.UTF8.GetBytes(Body);
 req.ContentLength = data.Length;
 using(Stream stream = req.GetRequestStream())
  stream.Write(data, 0, data.Length);
 using(Stream responseStream = req.GetResponse().GetResponseStream())
 using(StreamReader reader = new StreamReader(responseStream, Encoding.UTF8))
 {
  string result = reader.ReadToEnd();
 }
}