c# - How to solve my android Udp socket doesn't receive the packet sometime? -

firstly,i know risk of using udp socket instead of tcp.

i send image client c# server androids listening port using udp socket.

the problem can sometime receive packet in first attempt of sending( note :run c# console image sending app). sometime, have try more 1 attempts of sending in order receive it.

any or ideas appreciated. in advance

c# client code

        const int port = 4800;         string serverip = "?";          //get addresses         string hostname = system.net.dns.gethostname();         iphostentry alllocalnetworkaddresses = dns.resolve(hostname);          //walk thru network interfaces.         foreach (ipaddress ip in alllocalnetworkaddresses.addresslist)         {             socket client = new socket(addressfamily.internetwork, sockettype.dgram, protocoltype.udp);               //allow sending broadcast messages             client.setsocketoption(socketoptionlevel.socket,             socketoptionname.broadcast, 1);              //bind on port 0. os give port between 1025 , 5000.             client.bind(new ipendpoint(ip, 0));              //create endpoint, broadcast.             ipendpoint allendpoint = new ipendpoint(ipaddress.broadcast, port);                string path = "d:\\download.jpg";             filestream fs = new filestream(path, filemode.open, fileaccess.read);             binaryreader br = new binaryreader(fs);             byte[] data = br.readbytes(convert.toint16(fs.length));             client.sendto(data, allendpoint);                             console.write("client send 'image' " + allendpoint.tostring() +             environment.newline);          } 

android server

   protected string doinbackground(string... arg0) {         final textview text2 = (textview) findviewbyid(r.id.textview2);             try {             socket = new datagramsocket(port);                     int buf= socket.getreceivebuffersize();            byte[] receivedata = new byte[buf];             while (true) {                 final datagrampacket recv_packet = new datagrampacket(receivedata, receivedata.length);                 log.d("udp", "s: receiving...");                  socket.receive(recv_packet);                  byte[] buff = recv_packet.getdata();                    final bitmap new_img = bitmapfactory.decodebytearray(buff, 0,                         buff.length);                 runonuithread(new runnable() {                     @override                     public void run() {                         text2.settext("now connected");                                                  imageview image = (imageview) findviewbyid(r.id.imageview);                         image.setimagebitmap(new_img);                     }                  });              }         }         catch (exception e) {             log.e("udp", "s: error", e);             runonuithread(new runnable() {                 @override                 public void run() {                     //tv.settext("error occured");                 }             });         }      return text1; }