UDP异步接收数据问题（扒代码了！）

[fh1037723204]

目的：上位机开一个异步接收数据线程，用于接受下位机实时上传的数据。同时也可以主动发送数据。
过程：在类构造函数中开一个线程，用于异步接受下位机数据，再设置一个button，click后可以主动发送数据。定时器用于超时重传。
问题：用抓包软件检测显示，上位机数据可以发送出去，下位机相应数据包也可上传，但是程序好像没有进入异步接受调用函数ReceiveCallback（因为该函数中用来message.box函数显示一个对话框，程序执行中并没有出现）。
public partial class Form1 : Form
{

UdpClient UdpClient,u;
UdpState s;
private static Thread ThreadRevData;//定义一个线程
private static System.Timers.Timer aTimer;//定义一个定时器
static string SetIpString;
IPEndPoint SetIpEndPoint=null ,ee=null ; //发送数据用远端IP和端口
static byte[] GSendData; //用于重发的数组
static int TimerSend = 0;

private static bool messageReceived = false;
private static bool SendOrReturn = false;
public Form1()
{
UdpClient = new UdpClient();
InitializeComponent();
CheckForIllegalCrossThreadCalls = false;
Form1_Load();
}
private void Form1_Load() //加载异步监听线程
{
ThreadRevData = new Thread(new ThreadStart(listen));
ThreadRevData.IsBackground = true;
ThreadRevData.Start();
}
//监听接收数据
private void listen()
{
IPEndPoint ee = new IPEndPoint(IPAddress.Any, 99);
u = new UdpClient(ee);

s = new UdpState();
s.e = ee;
s.u = u;

u.BeginReceive(new AsyncCallback(ReceiveCallback), s);

while (!messageReceived)
{
Thread.Sleep(100);
}
}
public void ReceiveCallback(IAsyncResult ar)
{
u = (UdpClient)((UdpState)(ar.AsyncState)).u;
IPEndPoint ee = (IPEndPoint)((UdpState)(ar.AsyncState)).e;

Byte[] ReceiveBytes = u.EndReceive(ar, ref ee);

switch (ReceiveBytes[0]) //识别操作码
{
……
case 6:
{
if (ReceiveBytes[0] == GSendData[0] && ReceiveBytes[3] == 00)
{
aTimer.Stop(); //接受到数据包时关闭重发定时器
TimerSend = 0;
byte[] SendAck = { ReceiveBytes[0]，ReceiveBytes[1], ReceiveBytes[2], 1, ReceiveBytes[4], ReceiveBytes[5] };
GSendData = SendAck; //装配重发包
try
{
u.Send(SendAck, SendAck.Length, ee);
SendOrReturn = true;
}
catch (Exception SendError2)
{
MessageBox.Show(SendError2.ToString());
}

if (ReceiveBytes[2] < ReceiveBytes[1])
aTimer.Start();
break;
}
default: MessageBox.Show("ERROR DATA!"); break;
}

MessageBox.Show("laiguo");

u.BeginReceive(new AsyncCallback(ReceiveCallback), s); //继续监听
}

private void OnTimedEvent(object source, ElapsedEventArgs e)
{
if (TimerSend > 2) //重传发送次数满3次
{
ThreadRevData.Abort();//终止监听线程
aTimer.Stop();
aTimer.Dispose();
TimerSend = 0;//将发送次数置零
MessageBox.Show("通信失败！");
return;
}

try
{
if (SendOrReturn == false) //重发主动数据
UdpClient.Send(Form1.GSendData, Form1.GSendData.Length, SetIpEndPoint);
else //重发ACK
u.Send(Form1.GSendData, Form1.GSendData.Length, ee);
TimerSend++;
}
catch (Exception SendError3)
{
MessageBox.Show(SendError3.ToString());
}
}

private void Sendbutton_Click(object sender, EventArgs e)
{
ThreadRevData.Suspend();

string temp = this.UDPSend.Text; //临时存储发送区数据,以空格隔开
string[] StrArray = temp.Split(' ');//以大字符串中空格分割成子字符串
List<byte> bytes = new List<byte>();
foreach(string i in StrArray)
{
byte a=Convert.ToByte(i,16);
bytes.Add(a);
}
byte[] SendData = bytes.ToArray();
GSendData = SendData; //保存重发数据
SetIpString = this.IPTextBox1.Text; //读取默认IP地址

IPEndPoint SetIpEndPoint = new IPEndPoint(IPAddress.Parse(SetIpString), 99);
UdpClient.Connect(SetIpEndPoint);
aTimer = new System.Timers.Timer(1000);
aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
aTimer.AutoReset = true; //设置是执行一次（false）还是一直执行(true)；
TimerSend = 0; //超时重传次数置0

try
{
UdpClient.Send(SendData, SendData.Length);
SendOrReturn = false;
}
catch (Exception SendError1)
{
Console.WriteLine(SendError1.ToString());
}

aTimer.Enabled = true;//开始计时
ThreadRevData.Resume();
}

[我要坚强]

亲把 ReceiveCallback(IAsyncResult ar) 里面的switch理理干净，最好是从ReceiveCallback解救出来，放到外面按条件分支处理。为什么case 6:后面有个{号，少见少见。还有你怎么把 default也放在case6里面 MessageBox.Show("laiguo"); 到底有没有跳出switch外面在执行啊。哎一个字乱，两个字太乱，三个字真心乱

[fh1037723204]

目的：上位机开一个异步接收数据线程，用于接受下位机实时上传的数据。同时也可以主动发送数据。 过程：在类构造函数中开一个线程，用于异步接受下位机数据，再设置一个button，click后可以主动发送数据。定时器用于超时重传。 问题：用抓包软件检测显示，上位机数据可以发送出去，下位机相应数据包也可上传，但是程序好像没有进入异步接受调用函数ReceiveCallback（因为该函数中用来message.box函数显示一个对话框，程序执行中并没有出现）。 public partial class Form1 : Form { UdpClient UdpClient,u; UdpState s; private static Thread ThreadRevData;//定义一个线程 private static System.Timers.Timer aTimer;//定义一个定时器 static string SetIpString; IPEndPoint SetIpEndPoint=null ,ee=null ; //发送数据用远端IP和端口 static byte[] GSendData; //用于重发的数组 static int TimerSend = 0; private static bool messageReceived = false; private static bool SendOrReturn = false; public Form1() { UdpClient = new UdpClient(); InitializeComponent(); CheckForIllegalCrossThreadCalls = false; Form1_Load(); } private void Form1_Load() //加载异步监听线程 { ThreadRevData = new Thread(new ThreadStart(listen)); ThreadRevData.IsBackground = true; ThreadRevData.Start(); } //监听接收数据 private void listen() { IPEndPoint ee = new IPEndPoint(IPAddress.Any, 99); u = new UdpClient(ee); s = new UdpState(); s.e = ee; s.u = u; u.BeginReceive(new AsyncCallback(ReceiveCallback), s); while (!messageReceived) { Thread.Sleep(100); } } public void ReceiveCallback(IAsyncResult ar) { u = (UdpClient)((UdpState)(ar.AsyncState)).u; IPEndPoint ee = (IPEndPoint)((UdpState)(ar.AsyncState)).e; Byte[] ReceiveBytes = u.EndReceive(ar, ref ee); //数据处理， MessageBox.Show("laiguo"); u.BeginReceive(new AsyncCallback(ReceiveCallback), s); //继续监听 } private void OnTimedEvent(object source, ElapsedEventArgs e) { if (TimerSend > 2) //重传发送次数满3次 { ThreadRevData.Abort();//终止监听线程 aTimer.Stop(); aTimer.Dispose(); TimerSend = 0;//将发送次数置零 MessageBox.Show("通信失败！"); return; } try { if (SendOrReturn == false) //重发主动数据 UdpClient.Send(Form1.GSendData, Form1.GSendData.Length, SetIpEndPoint); else //重发ACK u.Send(Form1.GSendData, Form1.GSendData.Length, ee); TimerSend++; } catch (Exception SendError3) { MessageBox.Show(SendError3.ToString()); } } private void Sendbutton_Click(object sender, EventArgs e) { ThreadRevData.Suspend(); string temp = this.UDPSend.Text; //临时存储发送区数据,以空格隔开 string[] StrArray = temp.Split(' ');//以大字符串中空格分割成子字符串 List<byte> bytes = new List<byte>(); foreach(string i in StrArray) { byte a=Convert.ToByte(i,16); bytes.Add(a); } byte[] SendData = bytes.ToArray(); GSendData = SendData; //保存重发数据 SetIpString = this.IPTextBox1.Text; //读取默认IP地址 IPEndPoint SetIpEndPoint = new IPEndPoint(IPAddress.Parse(SetIpString), 99); UdpClient.Connect(SetIpEndPoint); aTimer = new System.Timers.Timer(1000); aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent); aTimer.AutoReset = true; //设置是执行一次（false）还是一直执行(true)； TimerSend = 0; //超时重传次数置0 try { UdpClient.Send(SendData, SendData.Length); SendOrReturn = false; } catch (Exception SendError1) { Console.WriteLine(SendError1.ToString()); } aTimer.Enabled = true;//开始计时 ThreadRevData.Resume(); }

[fh1037723204]

亲，ReceiveCallback函数里面的内容不是主要的！我已经清理了，请在看看！

[我要坚强]

 private void Sendbutton_Click(object sender, EventArgs e)
        {

            UdpClient udpClient = new System.Net.Sockets.UdpClient();
            byte[] SendData = { 0x13, 0x14 };           
            IPEndPoint SetIpEndPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 99);
            udpClient.Connect(SetIpEndPoint);
            try
            {
                udpClient.Send(SendData, SendData.Length);             
            }
            catch (Exception SendError1)
            {
                MessageBox.Show(SendError1.ToString());
            }

        }

测试过了，你的代码可以进入 ReceiveCallback(IAsyncResult ar)的哇

[fh1037723204]

你是怎么做的，怎么我就不行呢！