c# - Server start method throws exception, port already in use? -

i creating server-client application server , client can talk each other. when call start method on server, error saying this:

only 1 usage of each socket address (protocol/network address/port) permitted 

here program.cs:

using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using system.net; using system.net.sockets;  namespace networkingtest {     class program {         static void main(string[] args) {              bool readline = true;             string input = "";              while (true) {                 if (readline == true) {                     input = console.readline();                 }                  if (input == "server") {                     server server = new server(ipaddress.any, 12346);                     readline = false;                 }                  if (input == "client") {                     client client = new client(ipaddress.parse("myipv4"), 12346);                     readline = false;                 }             }          }     } } 

here server.cs:

using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using system.net; using system.net.sockets; using system.threading;  namespace networkingtest {     class server {         public tcplistener server;          public server (ipaddress ip, int port) {             server = new tcplistener(ip, port);             server.start();              thread serverrunthread = new thread(new threadstart(runserver));              serverrunthread.start();         }          void runserver () {             while (true) {                 tcpclient client = server.accepttcpclient();                 console.writeline("client connected!");                  thread serverhandlerthread = new thread(new parameterizedthreadstart(handleclient));                 serverhandlerthread.start(client);             }         }          void handleclient(object c) {             tcpclient client = (tcpclient)c;             networkstream stream = client.getstream();              int i;             string data = null;             byte[] bytes = new byte[256];              while((i = stream.read(bytes, 0, bytes.length)) != 0)  {                  data = encoding.ascii.getstring(bytes, 0, i);               console.writeline("received: " + data);                    }              stream.close();             client.close();         }     } } 

and here client.cs:

using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using system.net; using system.net.sockets; using system.threading;  namespace networkingtest {     class client {         public tcpclient client;          public client (ipaddress ip, int port) {             client = new tcpclient();             client.connect(ip, port);              thread thread = new thread(new threadstart(connecttoserver));             thread.start();         }          void connecttoserver () {             while (true) {                 string input = console.readline();                  if (input == "exit" || input == "quit" || input == "close") {                     break;                 } else {                     sendmessagetoserver(input);                 }             }         }          void sendmessagetoserver (string message) {             networkstream stream = client.getstream();             byte[] bytes = encoding.ascii.getbytes(message);             stream.write(bytes, 0, bytes.length);             stream.close();         }     } } 

edit: there problem in program.cs, fixed while loop:

        while (readline == true) {             input = console.readline();              if (input == "server") {                 server server = new server(ipaddress.any, 12346);                 readline = false;             }              if (input == "client") {                 client client = new client(ipaddress.parse("10.0.0.5"), 12346);                 readline = false;             }         } 

that happens because of error in while(true) loop. first ask user line console.readline(). if input "server" start server, go beginning of while loop , readline variable false, , input still "server", creates second server (basically have infinite loop). since have 1 sever on port - second try fails error see.

to fix, remove while loop, or more correctly, this:

static void main(string[] args) {     while (true) {         console.writeline("type \"server\" start server, type \"client\" start client, type \"exit\" exit");         string input = console.readline();          if (input == "server") {             server server = new server(ipaddress.any, 12346);         }         else if (input == "client") {             client client = new client(ipaddress.parse("myipv4"), 12346);         }         else if (input == "exit")             return;     } }