【发布时间】：2015-11-28 16:58:21
【问题描述】：
我正在尝试使用 C# TcpClient 通过 TCP 发送多个文件，对于 64kB 以下的文件效果很好，但是当我有更多文件时，它会抛出主机断开连接的异常。
这是我的代码：
服务器端（发送）。 1) SocketServer类
public abstract class SocketServer
{
private Socket serverSocket;
public SocketServer(IPEndPoint localEndPoint)
{
serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
serverSocket.Bind(localEndPoint);
serverSocket.Listen(0);
serverSocket.BeginAccept(BeginAcceptCallback, null);
}
private void BeginAcceptCallback(IAsyncResult ar)
{
Socket clientSocket = serverSocket.EndAccept(ar);
Console.WriteLine("Client connected");
ClientConnection clientConnection = new ClientConnection(this, clientSocket);
Thread clientThread = new Thread(new ThreadStart(clientConnection.Process));
clientThread.Start();
serverSocket.BeginAccept(BeginAcceptCallback, null);
}
internal abstract void OnReceiveMessage(ClientConnection client, byte header, byte[] data);
}
这里是客户端连接：
public class ClientConnection
{
private SocketServer server;
private Socket clientSocket;
private byte[] buffer;
private readonly int BUFFER_SIZE = 8192;
public ClientConnection(SocketServer server, Socket clientSocket)
{
this.server = server;
this.clientSocket = clientSocket;
buffer = new byte[BUFFER_SIZE];
}
public void Process()
{
clientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.Peek, BeginReceiveCallback, null);
}
private void BeginReceiveCallback(IAsyncResult ar)
{
int bytesReceived = clientSocket.EndReceive(ar);
if (bytesReceived >= 4)
{
clientSocket.Receive(buffer, 0, 4, SocketFlags.None);
// message size
int size = BitConverter.ToInt32(buffer, 0);
// read message
int read = clientSocket.Receive(buffer, 0, size, SocketFlags.None);
// if data still fragmented, wait for it
while (read < size)
{
read += clientSocket.Receive(buffer, read, size - read, SocketFlags.None);
}
ProcessReceivedData(size);
}
clientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.Peek, BeginReceiveCallback, null);
}
private void ProcessReceivedData(int size)
{
using (PacketReader pr = new PacketReader(buffer))
{
// message header = 1 byte
byte header = pr.ReadByte();
// next message data
byte[] data = pr.ReadBytes(size - 1);
server.OnReceiveMessage(this, header, data);
}
}
public void Send(byte[] data)
{
// first of all, send message length
clientSocket.Send(BitConverter.GetBytes(data.Length), 0, 4, SocketFlags.None);
// and then message
clientSocket.Send(data, 0, data.Length, SocketFlags.None);
}
}
FileServer类的实现：
public class FileServer : SocketServer
{
string BinaryPath;
public FileServer(IPEndPoint localEndPoint) : base(localEndPoint)
{
BinaryPath = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
}
internal override void OnReceiveMessage(ClientConnection client, byte hdr, byte[] data)
{
// Convert header byte to ENUM
Headers header = (Headers)hdr;
switch(header)
{
case Headers.Queue:
Queue(client, data);
break;
default:
Console.WriteLine("Wrong header received {0}", header);
break;
}
}
private void Queue(ClientConnection client, byte[] data)
{
// this message contains fileName
string fileName = Encoding.ASCII.GetString(data, 1, data.Length - 1);
// combine path with assembly location
fileName = Path.Combine(BinaryPath, fileName);
if (File.Exists(fileName))
{
FileInfo fileInfo = new FileInfo(fileName);
long fileLength = fileInfo.Length;
// pass the message that is now start a file transfer, contains:
// 1 byte = header
// 16 bytes = file length
using (PacketWriter pw = new PacketWriter())
{
pw.Write((byte)Headers.Start);
pw.Write(fileLength);
client.Send(pw.GetBytes());
}
//
using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read))
{
int read = 0, offset = 0;
byte[] fileChunk = new byte[8191];
while (offset < fileLength)
{
// pass message with file chunks, conatins
// 1 byte = header
// 8195 bytes = file chunk
using (PacketWriter pw = new PacketWriter())
{
fs.Position = offset;
read = fs.Read(fileChunk, 0, fileChunk.Length);
pw.Write((byte)Headers.Chunk);
pw.Write(fileChunk, 0, read);
client.Send(pw.GetBytes());
}
offset += read;
}
}
}
}
}
还有辅助类：
public class PacketWriter : BinaryWriter
{
private MemoryStream memoryStream;
public PacketWriter() : base()
{
memoryStream = new MemoryStream();
OutStream = memoryStream;
}
public byte[] GetBytes()
{
byte[] data = memoryStream.ToArray();
return data;
}
}
public class PacketReader : BinaryReader
{
public PacketReader(byte[] data) : base(new MemoryStream(data))
{
binaryFormatter = new BinaryFormatter();
}
}
客户端的代码几乎相同。接收除外：
internal override void OnReceiveMessage(ServerConnection client, byte hdr, byte[] data)
{
Headers header = (Headers)hdr;
switch(header)
{
case Headers.Start:
Start(data); // save length of file and prepare for receiving it
break;
case Headers.Chunk:
Chunk(data);
break;
default:
Console.WriteLine("Wrong header received {0}", header);
break;
}
}
private void Chunk(byte[] data)
{
// Process reveived data, write it into a file
}
【问题讨论】：
-
fileLength的数据类型是什么？ -
fileLength是整数 -
那不是一个类型，它是一组类型
标签： c# .net networking tcp