C# 如何使用 TCP 客户端发送 1GB 文件

Question

public void SendFile(string remoteHostIP, int remoteHostPort, string longFileName, string shortFileName)
{
    byte[] fileNameByte = Encoding.ASCII.GetBytes(shortFileName);
    byte[] fileData = File.ReadAllBytes(longFileName);
    byte[] clientData = new byte[4 + fileNameByte.Length + fileData.Length];
    byte[] fileNameLen = BitConverter.GetBytes(fileNameByte.Length);
    fileNameLen.CopyTo(clientData, 0);
    fileNameByte.CopyTo(clientData, 4);
    fileData.CopyTo(clientData, 4 + fileNameByte.Length);
    TcpClient clientSocket = new TcpClient(remoteHostIP, remoteHostPort);
    NetworkStream networkStream = clientSocket.GetStream();
    networkStream.Write(clientData, 0, clientData.GetLength(0));
    networkStream.Close();     
}

可以使用此功能发送 1GB 文件，因为我现在尝试发送的最大文件大小仅为 400MB。 不仅如此，还会导致“System.OutOfMemoryException”错误。 当我使用另一种方法将文件分成几个部分但服务器端无法连续接收这些部分而只能接收一个部分时。

    private void splitBigFile(string FileInputPath, byte[] inputArray)
    {
        int port = 1113;

        double partSize = 104852000;
        int partSize2 = 104852000;

        string FolderOutputPath = "C:\\Users\\xx\\Desktop\\testing split";
        string currPartPath;
        string shortNameSplit;

        FileStream fileStream = new FileStream(FileInputPath, FileMode.Open);
        FileInfo fiSource = new FileInfo(txtFile.Text);
        double sourceLength = fiSource.Length;

        partNum = (int)Math.Ceiling((double)(sourceLength / partSize));

        for (int i = 0; i < partNum; i++)
        {
            if (i == (partNum - 1))
            {
                partSize2 = (int)fiSource.Length - (i * 104852000);
            }

            currPartPath = FolderOutputPath + "\\" + fiSource.Name + "." + String.Format(@"{0:D4}", i) + ".part";
            shortNameSplit = fiSource.Name + "." + String.Format(@"{0:D4}", i) + ".part";

            byte[] fileNameByte = Encoding.ASCII.GetBytes(shortNameSplit);

            byte[] readStream = new byte[partSize2];

            byte[] concateFile = new byte[5 + fileNameByte.Length];

            int ipSend = ((partNum - 1 - i) << 1);
            ipSend |= 0; // for differentiate ip or file
            byte[] byteSend = new byte[1];
            byteSend[0] = (byte)ipSend;

            fileStream.Read(readStream, 0, partSize2);
            byte[] fileNameLen = BitConverter.GetBytes(fileNameByte.Length);

            byteSend.CopyTo(concateFile, 0);
            fileNameLen.CopyTo(concateFile, 1);
            fileNameByte.CopyTo(concateFile, 5);
            concateFile.CopyTo(inputArray, 0);
            readStream.CopyTo(inputArray, concateFile.Length);
            string ipAddress = "192.168.43.67";
            int sendport = 1113;
            //Task.Factory.StartNew(() => SendBigFileSize(ipAddress, sendport, inputArray[i]));
            Array.Clear(readStream, 0, readStream.Length);
            Array.Clear(fileNameLen, 0, fileNameLen.Length);
            Array.Clear(fileNameByte, 0, fileNameByte.Length);
            Array.Clear(byteSend, 0, byteSend.Length);
            Array.Clear(byteSend, 0, byteSend.Length);
        }
        fileStream.Close();
    }

Answer 1

当然，并不是一下子全部。 一次发送块。

此外，最大 TCP 数据包大小为 64k，MTU 为 1500 字节。 您的巨大缓冲区也被拆分了，但是您正在使用大量内存。 而是一次从文件中读取 32MB（安全 HDD I/O 缓冲区大小）并发送它，然后读取下一位。