C#•2y ago

send a response from TCP server to client

Exception says that objektreference is null Initiates these directly in Form

c#
TcpListener _lyssnare;
TcpClient _klient;
int _port = 12345;
IPAddress _ipAddress = IPAddress.Parse("127.0.0.1");
bool _ärServerIgång;
Kodhanterare _kodhanterare = new Kodhanterare();

c#
TcpListener _lyssnare;
TcpClient _klient;
int _port = 12345;
IPAddress _ipAddress = IPAddress.Parse("127.0.0.1");
bool _ärServerIgång;
Kodhanterare _kodhanterare = new Kodhanterare();

Starts server

c#
  public async void StartaServer()
    {
      try
      {
      _lyssnare = new TcpListener(_ipAddress, _port);
      _lyssnare.Start();
      _ärServerIgång = true;


      /// <summary>
      /// Väntar på meddelande
      /// </summary>
      try
      {
        lbl_info.Text = "väntar på koppling...";
        _klient = await _lyssnare.AcceptTcpClientAsync();
      }
      catch (ObjectDisposedException ex)
      {
      return;
      }
      lbl_info.Text = "kopplad till klient";
      StartaLäsning(_klient);
      }
      catch (Exception error)
      {
        MessageBox.Show(error.Message); return;
      }
      }

c#
  public async void StartaServer()
    {
      try
      {
      _lyssnare = new TcpListener(_ipAddress, _port);
      _lyssnare.Start();
      _ärServerIgång = true;


      /// <summary>
      /// Väntar på meddelande
      /// </summary>
      try
      {
        lbl_info.Text = "väntar på koppling...";
        _klient = await _lyssnare.AcceptTcpClientAsync();
      }
      catch (ObjectDisposedException ex)
      {
      return;
      }
      lbl_info.Text = "kopplad till klient";
      StartaLäsning(_klient);
      }
      catch (Exception error)
      {
        MessageBox.Show(error.Message); return;
      }
      }

Sends back response

c#
public async void StartaSändning(string meddelande)
{
// _klient in here is NULL despite initiated in Form and "used" in StartServer()

byte[] utdata = Encoding.Unicode.GetBytes(meddelande);
    try
    {
      await _klient.GetStream().WriteAsync(utdata, 0, utdata.Length);
      }
      catch (Exception error) 
      { MessageBox.Show(error.Message); return; }
}

c#
public async void StartaSändning(string meddelande)
{
// _klient in here is NULL despite initiated in Form and "used" in StartServer()

byte[] utdata = Encoding.Unicode.GetBytes(meddelande);
    try
    {
      await _klient.GetStream().WriteAsync(utdata, 0, utdata.Length);
      }
      catch (Exception error) 
      { MessageBox.Show(error.Message); return; }
}

12 Replies

Buddy•2y ago

Exception says that objektreference is null

Which line does it break at? Send a snippet of said line. $code

MODiX•2y ago

To post C# code type the following: ```cs // code here ``` Get an example by typing $codegif in chat If your code is too long, post it to: https://paste.mod.gg/

RonnieOP•2y ago

It breaks at

      await _klient.GetStream().WriteAsync(utdata, 0, utdata.Length);

      await _klient.GetStream().WriteAsync(utdata, 0, utdata.Length);

In the method that sends back response

Buddy•2y ago

Then I bet _klient is null

RonnieOP•2y ago

It is, but I dont understand why - does it not uphold a connection after intially connecting in the StartServer method?

 try
      {
        lbl_info.Text = "väntar på koppling...";
        _klient = await _lyssnare.AcceptTcpClientAsync();
      }

 try
      {
        lbl_info.Text = "väntar på koppling...";
        _klient = await _lyssnare.AcceptTcpClientAsync();
      }

Buddy•2y ago

please format the code correctly.

MODiX•2y ago

To post C# code type the following: ```cs // code here ``` Get an example by typing $codegif in chat If your code is too long, post it to: https://paste.mod.gg/

RonnieOP•2y ago

_klient = await _lyssnare.AcceptTcpClientAsync();

_klient = await _lyssnare.AcceptTcpClientAsync();

When I paste from VS, it jumbles it up sorry

Buddy•2y ago

Please use the site mentioned then paste the entire code.

RonnieOP•2y ago

https://paste.mod.gg/pmehvdocimdv/0

BlazeBin - pmehvdocimdv

A tool for sharing your source code with the world!

MODiX•2y ago

Please don't upload any potentially harmful files @ronnieyw, your message has been removed

RonnieOP•2y ago

Done, It works with a klient but i couldnt post it here beacuse .exe file i think

Gaming

Programming

send a response from TCP server to client