. NET network communication programming [using socket for transmission of strings, files, and serialized objects]-using encapsulated Network Services 4 [chat rooms]

In this case, a simple chat room is written using the encapsulated network service class, and TCP and asynchronous socket technologies are used:

App. config file:

 DemonstrationCode  <? XML version = "1.0" encoding = "UTF-8" ?>  <  Configuration  >      <  Appsettings  >          <! -- Local server name -->          <  Add   Key ="Servername"   Value = "127.0.0.1"  />          <! -- Local port -->          <  Add   Key = "SERVERPORT"   Value = "6001"  />          <! -- Remote server name -->          <  Add   Key ="Remoteservername"   Value = "127.0.0.1"  />          <! -- Remote server port -->          <  Add   Key = "Remoteserverport"   Value = "6002"  />      </  Appsettings  >  </ Configuration  > 

Complete chat form code:

 DEMO code Using system; using system. collections. generic; using system. componentmodel; using system. data; using system. drawing; using system. LINQ; using system. text; using system. windows. forms; using tcplabcommon; using system. net. sockets; using system. net; using system. configuration; using system. threading; using system. io; namespace tcplabchat1 {public partial class frmchat: FORM {delegate void updateviewhandler (netpacket packet); Delegate void updateviewwithmsghandler (string MSG );/// <  Summary  > /// File dialog box ///</  Summary  > Openfiledialog FD = new openfiledialog ();/// <  Summary  > /// TCP service object [provides the packet sending and package receiving functions] and receives messages and files /// </  Summary  > Netpacketservice tcppacketservicesvr = NULL ;/// <  Summary  > /// TCP service object [provides the packet sending and package receiving functions], and sends messages and files ///</  Summary  > Netpacketservice tcppacketserviceclient = NULL ;/// <  Summary  > /// Client socket [send messages and files] /// </  Summary  > Socket clientsocket = NULL ;/// <  Summary  > /// Local server name /// </ Summary  > Public String servername {get {return configurationmanager. receivettings ["servername"] ;}/// <  Summary  > /// Local listening port /// </  Summary  > Public int32 SERVERPORT {get {return convert. toint32 (configurationmanager. configurettings ["SERVERPORT"]) ;}/// <  Summary > /// Name of the Peer server /// </  Summary  > Public String remoteservername {get {return configurationmanager. deleetask[ "remoteservername"] ;}/// <  Summary  > /// The listening port of the other server /// </  Summary  > Public int32 remoteserverport {get {return convert. toint32 (configurationmanager. deleetask[ "remoteserverport"]) ;}} public frmchat () {initializecomponent () ;}private void frmchat_load (Object sender, eventargs e) {receivemessage ();}/// <  Summary  > /// Asynchronously receives messages from the other party /// </  Summary  > Private void receivemessage () {socket serversocket = new socket (addressfamily. interNetwork, sockettype. stream, protocoltype. TCP); endpoint = new ipendpoint (IPaddress. parse (servername), SERVERPORT); // create an endpoint serversocket. BIND (endpoint); // bind the endpoint serversocket. listen (0); // start listening to serversocket. beginaccept (New asynccallback (asynccallbackaccept), serversocket); // receives a request} private void asynccallbackaccept (iasyncresult result) {socket serversocket = (socket) result. asyncstate; socket ctsocket = serversocket. endaccept (result); networkstream netstream = new networkstream (ctsocket); tcppacketservicesvr = new netpackettcpasynservice (netstream); (tcppacketservicesvr as netpackettcpasynservice ). onreceivedpacket + = new tcpasynhandler1 (frmchat_onreceivedpacket); tcppacketservicesvr. extends epacket ();} void frmchat_onreceivedpacket (netpacket packet) {// run the delegate pointing method on the thread in the window interface to avoid cross-thread access to the UI issue invoke (New updateviewhandler (updateview ), packet );}///<  Summary  > /// Update the interface /// </  Summary  > /// <  Param   Name = "Packet"  >  </  Param  > Private void updateview (netpacket packet) {string msglist = txtmsglist. text; Switch (packet. packethead. ptype) {Case packettype. string: msglist + = "\ r \ n:" + packet. data. tostring (); break; Case packettype. binary: netfile F = tcppacketservicesvr. parsefile (byte []) packet. data); msglist + = "\ r \ n received the file sent by the recipient:" + F. filename; filestream FS = NULL; try {string fname = application. startuppath + "\" + F. filename; FS = new filestream (fname, filemode. create); FS. write (F. content, 0, F. content. length); FS. flush ();} catch (exception e) {MessageBox. show (E. message);} finally {FS. close ();} break; Case packettype. complex: break; default: break;} txtmsglist. TEXT = msglist;} private void updateview (string MSG) {string msglist = txtmsglist. text; msglist + = "\ r \ n" + MSG; txtmsglist. TEXT = msglist ;}///<  Summary  > /// Send a message /// </  Summary  > /// <  Param   Name = "Sender"  >  </  Param  > /// < Param   Name = "E"  >  </  Param  > Private void btnsendmsg_click (Object sender, eventargs e) {If (txtmsg. text. trim (). length = 0) return; If (clientsocket = NULL) {clientsocket = new socket (addressfamily. interNetwork, sockettype. stream, protocoltype. TCP); clientsocket. connect (IPaddress. parse (remoteservername), remoteserverport); networkstream netstream = new networkstream (clientsocket); tcppacketserviceclient = new netpackettcpasynservice (netstream);} // register an event, the function executed after successful sending [Note that this event is registered only once] // cancels the subscription event (tcppacketserviceclient as netpackettcpasynservice ). onaftersendpacket-= new tcpasynhandler2 (frmchat_onaftersendpacket); // subscribe to events again (tcppacketserviceclient as netpackettcpasynservice ). onaftersendpacket + = new tcpasynhandler2 (frmchat_onaftersendpacket); // send the packet tcppacketserviceclient. sendtext (txtmsg. text. trim ());}///<  Summary  > /// Function executed after successful sending /// </  Summary  > /// <  Param   Name = "MSG"  >  </  Param  > Void frmchat_onaftersendpacket (netpackethead packethead) {Switch (packethead. ptype) {Case packettype. string: String msglist = txtmsglist. text; msglist + = "\ r \ n:" + txtmsg. text. trim (); txtmsglist. TEXT = msglist; break; Case packettype. binary: // run the delegate pointing method in the thread in the window interface to avoid cross-thread access to the UI issue invoke (New updateviewwithmsghandler (updateview), "I sent the file: "+ new fileinfo (FD. filename ). name); break; Case packettype. complex: break; default: break ;}}/// <  Summary  > /// Send the file ///</  Summary  > /// <  Param   Name = "Sender"  >  </  Param  > /// <  Param   Name = "E"  > </  Param  > Private void btnsendfile_click (Object sender, eventargs e) {If (FD. showdialog () = system. windows. forms. dialogresult. cancel) {return;} If (clientsocket = NULL) {clientsocket = new socket (addressfamily. interNetwork, sockettype. stream, protocoltype. TCP); clientsocket. connect (IPaddress. parse (remoteservername), remoteserverport); networkstream netstream = new networkstream (clientsocket); tcppacketserviceclient = new netpackettcpasynservice (netstream);} // register an event, the function executed after successful sending [Note that this event is registered only once] // cancels the subscription event (tcppacketserviceclient as netpackettcpasynservice ). onaftersendpacket-= new tcpasynhandler2 (frmchat_onaftersendpacket); // subscribe to events again (tcppacketserviceclient as netpackettcpasynservice ). onaftersendpacket + = new tcpasynhandler2 (frmchat_onaftersendpacket); tcppacketserviceclient. sendfile (FD. filename );}}}