我正在使用TcpClient和TcpListener类创建客户端/服务器聊天应用程序。它应该能够在客户端和服务器之间传输文本消息和文件。我能够通过为每个单独的客户端创建一个线程来处理文本消息，然后创建一个辅助线程来接收传入消息，使主线程保留用于发送消息。现在，如果我能够识别传入的消息是文件而不是文本消息，那么我知道如何使用NetworkStream和FileStream来处理它。但我无法这样做。处理传入文件的代码是here。如果使用NetworkStream for FTP有任何限制，请告诉我。
答案 0 :(得分：1)
答案：建立自己的协议。
通过构建自己的良好通信协议，您可以控制所有数据/消息流。
例如;
1 - 用户想要将文件发送到服务器
2-Client发送命令通知服务器它将发送文件。喜欢;
@File@filename;filesize;
3服务器将准备好的消息发送回客户端@FileAccepted@
4-Server开始监听缓冲包，当它接收时将它们写入流中
5-当客户端收到{@FileAccepted@}命令时，开始将包发送到服务器。确保它们的缓冲区大小相同
6-当所有字节完成客户端在不同缓冲区中发送@FileEnd@时（我使用256表示命令，1024表示文件传输）
7-当服务器收到256字节命令时查看其@FileEnd@命令是否为真，刷新文件流并关闭连接。
我建议您使用Async
像这样监听服务器上的连接
server.BeginAcceptTcpClient(ServerAcceptEnd,server);
当存在连接时
public void ServerAcceptEnd(IAsyncResult ar)
{
if(!ar.IsCompleted)
{
//Something went wrong
AcceptServer();
return;
}
try
{
var cli = servertc.EndAcceptTcpClient(ar);
if(cli.Connected)
{
//Get the first Command
cli.GetStream().BeginRead(serverredbuffer,0,serverredbuffer.Length,ServerFirstReadEnd,cli);
}
else
{
//Connection was not successfull log and wait
AcceptServer();
}
}
catch(Exceiption ex)
{
//An error occur log and wait for new connections
AcceptServer();
}
}
收到第一个命令时;
public void ServerFirstReadEnd(IAsyncResult ar)
{
if(!ar.IsCompleted)
{
//Something went wrong
AcceptServer();
return;
}
try
{
TcpClient cli = (TcpClient)ar.AsyncState;
int read = cli.GetStream().EndRead(ar);
string req = toString(serverredbuffer);
if(req.StartsWith("@File@"))
{
//File Received
string filename = req.Replace("@File@","");
string[] spp = filename.Split(';');
filename = spp[0];
serverreceivetotalbytes = Convert.ToInt64(spp[1]);
cli.GetStream().Write(toByte("@FileAccepted@",256),0,256);
cli.GetStream().BeginRead(serverreceivebuffer,0,1024,ServerReadFileCyle,cli)
}
else
{
//Message Received
}
}
catch(Exception ex)
{
//An error occur log and wait for new connections
AcceptServer();
}
}
文件接收方法;
public void ServerReadFileCyle(IAsyncResult ar)
{
TcpClient cli = (TcpClient)ar.AsyncState;
if(ar.IsCompleted)
{
int read = cli.GetStream().EndRead(ar);
if(read == 256)
{
try
{
string res = toString(serverreceivebuffer);
if(res == "@FileEnd@")
read = 0;
}
catch
{
}
}
if(read > 0)
{
serverfile.Write(serverreceivebuffer,0,read);
cli.GetStream().BeginRead(serverreceivebuffer,0,1024,ServerReadFileCyle,cli);
}
else
{
serverfile.Flush();
serverfile.Dispose();
AcceptServer();
}
}
}
这部分是服务器端。对于客户端;
首先发送文件向服务器发送信息，然后等待服务器的响应。
try
{
System.Windows.Forms.OpenFileDialog ofd = new System.Windows.Forms.OpenFileDialog();
ofd.Multiselect = false;
ofd.FileName="";
if(ofd.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
filesendpath = ofd.FileName;
senderfilestream = System.IO.File.Open(filesendpath,System.IO.FileMode.Open);
sendertotalbytes = senderfilestream.Length;
filesendcommand = "@File@" + System.IO.Path.GetFileName(filesendpath) + ";" + senderfilestream.Length;
senderfilestream.Position = 0;
sendertc.BeginConnect(ip.Address,55502,FileConnect,null);
}
else
{
//No file selected
}
}
catch(Exception ex)
{
//Error connecting log the error
}
如果连接成功，则发送文件命令并等待响应;
public void FileConnect(IAsyncResult ar)
{
if(ar.IsCompleted)
{
sender.EndConnect(ar);
if(sender.Connected)
{
sender.GetStream().Write(toByte(filesendcommand,256),0,256);
sender.GetStream().BeginRead(ComputerNameBuffer,0,256,FileSendCyleStarter,null);
}
}
}
收到回复时看看是否成功接受;
public void FileSendCyleStarter(IAsyncResult ar)
{
if(ar.IsCompleted)
{
if(sender.Connected)
{
string kabul = toString(ComputerNameBuffer);
if(kabul == "@FileAccepted@")
{
senderfilestream.BeginRead(filesendbuffer,0,1024,FileSendCyle,null);
}
}
}
}
发送文件有三个步骤;
1 - 阅读一个块开始
2 - 然后将块发送到server.if完成send @ FileEnd @命令并跳过步骤3
3 - 阅读下一个文件块
4 - 如果文件未完成则返回步骤2
第1步：
senderfilestream.BeginRead(filesendbuffer,0,1024,FileSendCyle,null);
步骤2-4：
public void FileSendCyle(IAsyncResult ar)
{
if(ar.IsCompleted)
{
if(sendertc.Connected)
{
int read = senderfilestream.EndRead(ar);
if(read > 0)
{
sendertc.GetStream().BeginWrite(filesendbuffer,0,read,FileSendCyle2,null);
}
else
{
sendertc.GetStream().Write(toByte("@FileEnd@",256),0,256);
}
}
}
}
第3步：
public void FileSendCyle2(IAsyncResult ar)
{
if(ar.IsCompleted)
{
if(sendertc.Connected)
{
sendertc.GetStream().EndWrite(ar);
senderfilestream.BeginRead(filesendbuffer,0,1024,FileSendCyle,null);
}
}
}
在abowe示例中，有两个名为toString（）和toByte（）的方法。我用它们将字符串转换为字节，将字节转换为字符串。这些是它们;
public string toString(byte[] buffer)
{
return Encoding.UTF8.GetString(buffer).Replace("\0","");
}
public byte[] toByte(string str,int bufferlenght)
{
byte[] buffer = new byte[256];
Encoding.UTF8.GetBytes(str,0,str.Length,buffer,0);
return buffer;
}
代码abowe示例并不完美，需要大量的错误处理和流量控制。我写了这些给你一个想法和一个快速启动。
希望它的任何部分都能帮助任何人^ _ ^