class Program{  public static DateTime? Expiration { get; set; }  public static readonly DateTime DoNotStore = DateTime.MinValue;  private static readonly DateTime UNIX_EPOCH = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);  private static string DeviceToken = "273eeddaef02192cf4ba5b666453b258f2d2a1ad02f549105fd03fea789d809d";  public const int DEVICE_TOKEN_BINARY_SIZE = 32;  public const int DEVICE_TOKEN_STRING_SIZE = 64;  public const int MAX_PAYLOAD_SIZE = 256;  private static X509Certificate certificate;  private static X509CertificateCollection certificates;  static void Main(string[] args)  {   string hostIP = "gateway.sandbox.push.apple.com";//   int port = 2195;   string password = "ankejiaoyu";//   string certificatepath = "aps_developer_identity.p12";//bin/debug   string p12Filename = System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, certificatepath);   certificate = new X509Certificate2(System.IO.File.ReadAllBytes(p12Filename), password, X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet | X509KeyStorageFlags.Exportable);   certificates = new X509CertificateCollection();   certificates.Add(certificate);   TcpClient apnsClient = new TcpClient();   apnsClient.Connect(hostIP, port);   SslStream apnsStream = new SslStream(apnsClient.GetStream(), false, new RemoteCertificateValidationCallback(validateServerCertificate), new LocalCertificateSelectionCallback(selectLocalCertificate));   try   {    //APNs已不支持SSL 3.0     apnsStream.AuthenticateAsClient(hostIP, certificates, System.Security.Authentication.SslProtocols.Tls, false);   }   catch (System.Security.Authentication.AuthenticationException ex)   {    Console.WriteLine("error+"+ex.Message);   }   if (!apnsStream.IsMutuallyAuthenticated)   {    Console.WriteLine("error:Ssl Stream Failed to Authenticate！");   }   if (!apnsStream.CanWrite)   {    Console.WriteLine("error:Ssl Stream is not Writable!");   }   Byte[] message = ToBytes();   apnsStream.Write(message);  }  public static byte[] ToBytes()  {   // Without reading the response which would make any identifier useful, it seems silly to   // expose the value in the object model, although that would be easy enough to do. For   // now we'll just use zero.   int identifier = 0;   byte[] identifierBytes = BitConverter.GetBytes(IPAddress.HostToNetworkOrder(identifier));   // APNS will not store-and-forward a notification with no expiry, so set it one year in the future   // if the client does not provide it.   int expiryTimeStamp = -1;//過期時間戳   if (Expiration != DoNotStore)   {    //DateTime concreteExpireDateUtc = (Expiration ?? DateTime.UtcNow.AddMonths(1)).ToUniversalTime();    DateTime concreteExpireDateUtc = (Expiration ?? DateTime.UtcNow.AddSeconds(20)).ToUniversalTime();    TimeSpan epochTimeSpan = concreteExpireDateUtc - UNIX_EPOCH;    expiryTimeStamp = (int)epochTimeSpan.TotalSeconds;   }   byte[] expiry = BitConverter.GetBytes(IPAddress.HostToNetworkOrder(expiryTimeStamp));   byte[] deviceToken = new byte[DeviceToken.Length / 2];   for (int i = 0; i < deviceToken.Length; i++)    deviceToken[i] = byte.Parse(DeviceToken.Substring(i * 2, 2), System.Globalization.NumberStyles.HexNumber);   if (deviceToken.Length != DEVICE_TOKEN_BINARY_SIZE)   {    Console.WriteLine("Device token length error！");   }   byte[] deviceTokenSize = BitConverter.GetBytes(IPAddress.HostToNetworkOrder(Convert.ToInt16(deviceToken.Length)));   string str = "{/"aps/":{/"alert/":/"這是測試消息??！/",/"badge/":1,/"sound/":/"anke.mp3/"}}";   byte[] payload = Encoding.UTF8.GetBytes(str);   byte[] payloadSize = BitConverter.GetBytes(IPAddress.HostToNetworkOrder(Convert.ToInt16(payload.Length)));   List<byte[]> notificationParts = new List<byte[]>();   //1 Command   notificationParts.Add(new byte[] { 0x01 }); // Enhanced notification format command   notificationParts.Add(identifierBytes);   notificationParts.Add(expiry);   notificationParts.Add(deviceTokenSize);   notificationParts.Add(deviceToken);   notificationParts.Add(payloadSize);   notificationParts.Add(payload);   return BuildBufferFrom(notificationParts);  }  private static byte[] BuildBufferFrom(IList<byte[]> bufferParts)  {   int bufferSize = 0;   for (int i = 0; i < bufferParts.Count; i++)    bufferSize += bufferParts[i].Length;   byte[] buffer = new byte[bufferSize];   int position = 0;   for (int i = 0; i < bufferParts.Count; i++)   {    byte[] part = bufferParts[i];    Buffer.BlockCopy(bufferParts[i], 0, buffer, position, part.Length);    position += part.Length;   }   return buffer;  }  private static bool validateServerCertificate(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)  {   return true; // Dont care about server's cert  }  private static X509Certificate selectLocalCertificate(object sender, string targetHost, X509CertificateCollection localCertificates,   X509Certificate remoteCertificate, string[] acceptableIssuers)  {   return certificate;  }}