我尝试使用MSDN(https://msdn.microsoft.com/en-us/library/6y0e13d3%28v=vs.110%29.aspx)
中的示例编写自己的应用程序任务是将对象发送到服务器并获得它已收到的反馈。我有一个表单,我点击按钮将信息发送到服务器。我的问题是,如果我启动服务器和客户端,我点击按钮 - 我发送一个对象并从服务器获得反馈,如果我再次单击该按钮有时它有效,有时我得到:
Sent 595 bytes to server.
Response received : Mustermann
Exception thrown: 'System.ObjectDisposedException' in System.dll
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'System.Net.Sockets.Socket'.
at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult, SocketError& errorCode)
at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)
at Zakinator.AsynchronousClient.ReceiveCallback(IAsyncResult ar) in C:\Data\1_Progs\Me\Zakinator\Zakinator\Client.cs:line 144
在带有Buttonclick的表单上我只调用Client StartClient(Communicator communicator,WriteLog writeLog)中的函数
我的客户代码:
namespace Zakinator
{
public delegate void WriteLog(string msg);
// State object for receiving data from remote device.
public class StateObject
{
// Client socket.
public Socket workSocket = null;
// Size of receive buffer.
public const int BufferSize = 256;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
// Received data string.
public StringBuilder sb = new StringBuilder();
}
public class AsynchronousClient
{
private static WriteLog wl;
// The port number for the remote device.
private const int port = 11000;
// ManualResetEvent instances signal completion.
private static ManualResetEvent connectDone =
new ManualResetEvent(false);
private static ManualResetEvent sendDone =
new ManualResetEvent(false);
private static ManualResetEvent receiveDone =
new ManualResetEvent(false);
// The response from the remote device.
private static String response = String.Empty;
public static void StartClient(Communicator communicator,WriteLog writeLog)
{
wl = writeLog;
// Connect to a remote device.
try
{
// Establish the remote endpoint for the socket.
// The name of the
// remote device is "host.contoso.com".
IPHostEntry ipHostInfo = Dns.Resolve("localhost");
IPAddress ipAddress = ipHostInfo.AddressList[0];
IPEndPoint remoteEP = new IPEndPoint(ipAddress, port);
// Create a TCP/IP socket.
Socket client = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
// Connect to the remote endpoint.
client.BeginConnect(remoteEP,
new AsyncCallback(ConnectCallback), client);
connectDone.WaitOne();
// Send test data to the remote device.
Send(client, communicator);
//sendDone.WaitOne();
// Receive the response from the remote device.
Receive(client);
receiveDone.WaitOne();
// Write the response to the console.
Debug.Print(String.Format("Response received : {0}", response));
// Release the socket.
client.Shutdown(SocketShutdown.Both);
client.Close();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
private static void ConnectCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket client = (Socket)ar.AsyncState;
// Complete the connection.
client.EndConnect(ar);
Debug.Print(String.Format("Socket connected to {0}",client.RemoteEndPoint.ToString()));
// Signal that the connection has been made.
connectDone.Set();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
private static void Receive(Socket client)
{
try
{
// Create the state object.
StateObject state = new StateObject();
state.workSocket = client;
// Begin receiving the data from the remote device.
client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReceiveCallback), state);
}
catch (Exception e)
{
Debug.Print(e.ToString());
}
}
private static void ReceiveCallback(IAsyncResult ar)
{
try
{
// Retrieve the state object and the client socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket client = state.workSocket;
// Read data from the remote device.
int bytesRead = client.EndReceive(ar);
if (bytesRead > 0)
{
// There might be more data, so store the data received so far.
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
// Get the rest of the data.
client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,new AsyncCallback(ReceiveCallback), state);
}
else
{
// All the data has arrived; put it in response.
if (state.sb.Length > 1)
{
response = state.sb.ToString();
}
// Signal that all bytes have been received.
receiveDone.Set();
}
}
catch (Exception e)
{
Debug.Print(e.ToString());
}
}
private static void Send(Socket client, byte[] byteData)
{
// Begin sending the data to the remote device.
client.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), client);
}
private static void Send(Socket client, Communicator data)
{
byte[] byteData;
MemoryStream ms = new MemoryStream();
BinaryFormatter bf1 = new BinaryFormatter();
bf1.Serialize(ms, data);
byteData = ms.ToArray();
Send(client, BitConverter.GetBytes(byteData.Length));
sendDone.WaitOne();
Send(client, byteData);
sendDone.WaitOne();
}
private static void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket client = (Socket)ar.AsyncState;
// Complete sending the data to the remote device.
int bytesSent = client.EndSend(ar);
Debug.Print(String.Format("Sent {0} bytes to server.", bytesSent));
// Signal that all bytes have been sent.
sendDone.Set();
}
catch (Exception e)
{
Debug.Print(e.ToString());
}
}
}
}
我的服务器代码:
namespace ServerZakinator
{
// State object for reading client data asynchronously
public class StateObject
{
// Client socket.
public Socket workSocket = null;
// Size of receive buffer.
public const int BufferSize = 1024;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
// Received data string.
public StringBuilder sb = new StringBuilder();
// incoming image size
public int ObjectSize;
}
public class AsynchronousSocketListener
{
// Thread signal.
public static ManualResetEvent allDone = new ManualResetEvent(false);
private static System.Timers.Timer SentCommunicatorToInfo = new System.Timers.Timer();
private static byte[] _objectBuff;
private static int _totBytesRead = 0;
public static int Port=11000;
public static string Host = "127.0.0.1";
private static List<Communicator> CommunicatorsList = new List<Communicator>();
public delegate void DataReceived(Communicator communicator);
public static event DataReceived NewData;
protected static void SendToWinwow(Communicator communicator)
{
CommunicatorsList.Add(communicator);
}
public AsynchronousSocketListener()
{
}
public static void StartListening()
{
//SetUp Timer
SentCommunicatorToInfo.Interval = 1000;
SentCommunicatorToInfo.Enabled = true;
SentCommunicatorToInfo.Elapsed += new ElapsedEventHandler(OnTimedEvent);
// Data buffer for incoming data.
byte[] bytes = new Byte[1024];
// Establish the local endpoint for the socket.
// The DNS name of the computer
// running the listener is "host.contoso.com".
IPHostEntry ipHostInfo = Dns.GetHostEntry(Host);
IPAddress ipAddress = ipHostInfo.AddressList[0];
IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Parse(Host), Port);
// Create a TCP/IP socket.
Socket listener = new Socket(AddressFamily.InterNetwork,SocketType.Stream, ProtocolType.Tcp);
// Bind the socket to the local endpoint and listen for incoming connections.
try
{
listener.Bind(localEndPoint);
listener.Listen(100);
while (true)
{
// Set the event to nonsignaled state.
allDone.Reset();
// Start an asynchronous socket to listen for connections.
Console.WriteLine("Waiting for a connection...");
listener.BeginAccept(new AsyncCallback(AcceptCallback),listener);
// Wait until a connection is made before continuing.
allDone.WaitOne();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
private static void OnTimedEvent(object source, ElapsedEventArgs e)
{
if (NewData != null)
{
var item = CommunicatorsList.FirstOrDefault();
if (item == null)
return;
NewData(item);
CommunicatorsList.Remove(item);
}
}
public static void AcceptCallback(IAsyncResult ar)
{
// Signal the main thread to continue.
allDone.Set();
// Get the socket that handles the client request.
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
// Create the state object.
StateObject state = new StateObject();
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,new AsyncCallback(ReadHeaderCallback), state);
}
public static void ReadHeaderCallback(IAsyncResult ar)
{
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.EndReceive(ar);
//we need to add error handler here...but later
state.ObjectSize = BitConverter.ToInt32(state.buffer, 0);
_objectBuff = new byte[state.ObjectSize];
_totBytesRead = 0;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
public static void ReadCallback(IAsyncResult ar)
{
String content = String.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
// There might be more data, so store the data received so far.
Buffer.BlockCopy(state.buffer, 0, _objectBuff, _totBytesRead, bytesRead);
_totBytesRead += bytesRead;
if (_totBytesRead < state.ObjectSize)
{
// Not all data received. Get more.
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
else
{
MemoryStream ms = new MemoryStream(_objectBuff);
BinaryFormatter bf1 = new BinaryFormatter();
ms.Position = 0;
object rawObj = bf1.Deserialize(ms);
Communicator msgObj = (Communicator)rawObj;
SendToWinwow(msgObj);
Send(handler, msgObj);
}
}
}
private static void Send(Socket handler, Communicator communicator)
{
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Encoding.ASCII.GetBytes(communicator.Patient.Name);
// Begin sending the data to the remote device.
handler.BeginSend(byteData, 0, byteData.Length, 0,new AsyncCallback(SendCallback), handler);
}
private static void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket handler = (Socket)ar.AsyncState;
// Complete sending the data to the remote device.
int bytesSent = handler.EndSend(ar);
Debug.Print("Sent {0} bytes to client.", bytesSent);
handler.Shutdown(SocketShutdown.Both);
handler.Close();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
}
}
答案 0 :(得分:0)
Receive(client);
立即返回。调用ReceiveCallback时,您的客户端已在StartClient方法中关闭。