如何通过 tcp 套接字发送和接收文件

Question

现在我知道这个问题被问了很多，但我真的不知道该怎么做。我试过了，但文件不完整我只收到了一点文件，其余的只是 NULL 这是我在客户端部分的代码我首先向服务器发送一条包含文件大小的消息，如下所示：

// here I send the a upload request with the size of the file that I want to send
byte[] data = Encoding.Unicode.GetBytes("uploadreq~"+new FileInfo(ofg.FileName).Length);
// here is the socket client    
target.Send(data);

然后在服务器端：

if (cmd.Contains(update.update_request))
{
    // here I set an int var to the file size
    update.update_size = int.Parse(cmd.Split('~')[1]);

    // here I setup the a new byte array with the given file size
    update.update_received = new byte[update.update_size];

    // then I send a upload confirm command 
    Connection.sendCommand(Commands.update_confirme);
    update.isupdate = true;
}

收到确认后再次在客户端：

if (cmd.StartsWith("updateConfirm"))
{
    // reading all the bytes of the file and sending them
    byte[] datatosend = File.ReadAllBytes("the file path");
    Connection.send_bytes(datatosend);
}

终于在客户端了：

private void receiveInfo()
{
    byte[] buffer = new byte[999999];
    int received = 0;

    try
    {
        received =  Connection.clientSocket.Receive(buffer);
    }
    catch (SocketException)
    {
        Connection.clientSocket.Close();
        Connection.clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        Connection.makeConnection();
    }

    if (received == 0)
        return;

    byte[] data = new byte[received];
    Array.Copy(buffer, data, received);
       
    if (update.isupdate == true)
    {
         // this calls a method that process the data received 
         update.process_update(data);
    }
}

public static void process_update(byte[] data)
{
    int writeSize = 0;
    Buffer.BlockCopy(data, 0, update_received, writeSize, data.Length);
    writeSize += data.Length;

    if (update_received.Length == update_size)
    {
        using (FileStream fs = File.Create("the path to where the file shloud go"))
        {
            byte[] info = update_received;
            fs.Write(info, 0, info.Length);
        }

        Array.Clear(update_received, 0, update_received.Length);
      
        isupdate = false;
    }
}

当我写这个问题时，我在接收信息方法中更改了缓冲区大小，这似乎改变了一些东西，但文件不会完全到达..

Answer 1

为客户试试这个：

private void SendFile(String FileName,String IPAddress,int  Port )
{
        System.Net.Sockets.TcpClient TcpClient = new System.Net.Sockets.TcpClient(IPAddress, Port);
        System.Net.Sockets.NetworkStream NetworkStream = TcpClient.GetStream();
        System.IO.Stream FileStream = System.IO.File.OpenRead(FileName);
        byte[] FileBuffer = new byte[FileStream.Length];
        
        FileStream.Read(FileBuffer, 0, (int)FileStream.Length);
        NetworkStream.Write(FileBuffer, 0, FileBuffer.GetLength(0));
        NetworkStream.Close();
}

这是服务器的代码：

private void ReceiveFile(String FilePath, int Port)
    {
        System.Threading.Thread WorkerThread = new System.Threading.Thread(() =>
        {
            System.Net.Sockets.TcpListener TcpListener = new System.Net.Sockets.TcpListener(System.Net.IPAddress.Any, 60000);
            TcpListener.Start();
            System.Net.Sockets.Socket HandlerSocket = TcpListener.AcceptSocket();
            System.Net.Sockets.NetworkStream NetworkStream = new System.Net.Sockets.NetworkStream(HandlerSocket);
            int BlockSize = 1024;
            int DataRead = 0;
            Byte[] DataByte = new Byte[BlockSize];
            lock (this)
            {
                System.IO.Stream FileStream = System.IO.File.OpenWrite(FilePath);

                while (true)
                {
                    DataRead = NetworkStream.Read(DataByte, 0, BlockSize);
                    FileStream.Write(DataByte, 0, DataRead);
                    if (DataRead == 0)
                    {
                        break;
                    }
                }
                FileStream.Close();
            }
        });
        WorkerThread.Start();
    }

这只会传输一个文件。