Java and C # UDP communication problem

Java as a UDP server
C # as the UDP client.
Source Code

  package com.taoge.socke;
  import java.io.IOException;
  import java.net.DatagramPacket;
  import java.net.DatagramSocket;
  
  public class UDPEchoServer {
  	private static final int ECHOMAX=255;//max size of echo datagram
  	
  	public static void main(String[] args) throws IOException {
  		/*
  			if(args.length!=1){
  				throw new IllegalArgumentException("Parameter(s):<Port>");
  			}
  		*/
  		//int servPort=Integer.parseInt(args[0]);
  		int servPort = 5555;
  		
  		//1.创建一个DatagramSocket实例，指定本地端口号，可以选择指定本地地址
  		DatagramSocket socket=new DatagramSocket(servPort);
  		DatagramPacket packet=new DatagramPacket(new byte[ECHOMAX],ECHOMAX);
  		
  		while(true){
  			//2.使用DatagramSocket的receive方法来接收一个DatagramPacket实例。
  			socket.receive(packet);
  			System.out.println("Handling client at "+packet.getAddress().getHostAddress()+" on port "+packet.getPort());
  			System.out.println("包的数据:" + new String(packet.getData()));
  			socket.send(packet);
  			packet.setLength(ECHOMAX);
  			//socket.close();
  		}
  	}
  }
  

C # part

  using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using System.Threading.Tasks;
  using System.Net;
  using System.Net.Sockets;
  
  namespace ConsoleApplication1
  {
  
      /**
       * C# 版本UDP客户端，用与连接Java服务器端发送数据。
       * */
      class Program
      {
         
  
          static void Main(string[] args)
          {
              int SenderPort = 5555;
              String host = "127.0.0.1";
  
              IPAddress ip = IPAddress.Parse(host);
              IPEndPoint ipepoit = new IPEndPoint(ip,SenderPort);
  
              UdpClient udpClient = new UdpClient(SenderPort);
              udpClient.Connect(ip,SenderPort);
  
              Byte[] sendByts = Encoding.ASCII.GetBytes("welcome to chengdu!!");
  
              //udpClient.Send(sendByts,sendByts.Length);
              udpClient.Send(sendByts, 255);
              //IPEndPoint RemoteIpEndPoint = new IPEndPoint(ip, 0);
  
              //Byte[] receiveBytes = udpClient.Receive(ref RemoteIpEndPoint);
              //string returnData = Encoding.ASCII.GetString(receiveBytes);
  
              //Console.WriteLine("This is the message you received " + returnData.ToString());
              //Console.WriteLine("This message was sent from " + RemoteIpEndPoint.Address.ToString() + " on their port number " + RemoteIpEndPoint.Port.ToString());
              Console.WriteLine("发送数据完毕!!");
              udpClient.Close();
  
          }
      }
  }
  
  

now send messages to the Java C # , Java can not receive this message .

Java to Java send no problem , C # to C # to send no problem , now is the C # to Java problems.
------ Solution ---------------------------------------- ----
expressed c # learned , there is pressure
------ Solution - -------------------------------------------
do with mina < br> ------ Solution ----------------------------------------- ---
I like to use the socket, the original flavor of Kazakhstan , Java did not make changes , C # is slightly changed a bit , Java clients can receive data .

              int SenderPort = 5555;
              String host = "127.0.0.1";
              IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Parse(host),SenderPort);
  
              Byte[] sendByts = Encoding.ASCII.GetBytes("welcome to chengdu!!");
              Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
              socket.SendTo(sendByts,sendByts.Length, SocketFlags.None, RemoteIpEndPoint);
              
  
              Console.WriteLine("发送数据完毕!!");
              socket.Close();

------ Solution ------------------------------------- -------
should message is received , but when sent from C # Java does not know where the demarcation point is the message frame and still cached in the message queue.
------ For reference only -------------------------------------- -


In fact, I have learned , but also to write the C # program , which means that pressure Alexander !
------ For reference only -------------------------------------- -
anyone know this problem?
------ For reference only -------------------------------------- -


What's this ?
------ For reference only -------------------------------------- -

yesterday I tested , there is no problem with the way the socket , using C # udpclient class is not, or use socket forget.
------ For reference only -------------------------------------- -
udpclient inside of the socket of the package, I am also not familiar with it .

udpClient.Send (sendByts, 255); This line should be an error , because the packets are not so long , the other seems to be no problem .
------ For reference only -------------------------------------- -
Hello ! I also encountered the same problem with you . UDP mode of communication is how you ask the next solution .