Question

我是编程新手，我遇到了一个无法解决的问题。我创建了一个共享文件的程序，比如dropbox。我有一台服务器，工作正常，客户端。问题是，当我尝试从服务器下载文件时，似乎流中缺少一些字节。

clientSocket = new TcpClient(Program.host, Program.port);
NetworkStream networkStream = clientSocket.GetStream();
StreamWriter write = new StreamWriter(networkStream);
write.WriteLine(need);
write.Flush();
write.WriteLine(loca);
write.Flush();
StreamReader read = new StreamReader(networkStream);
Int64 size = Convert.ToInt64(read.ReadLine());
long blocks = size / 1024;
long blocksDown = 0;
try
{
    string fileName = string.Empty;
    int qtd = 0;
    int blockSize = 1024;
    double progress = 0;
    Int64 qtdDown = 0;
    Byte[] dataByte = new Byte[blockSize];
    bool download = true;
    lock (this)
    {
        networkStream.Read(dataByte, 0, dataByte.Length);
        int fileNameLen = BitConverter.ToInt32(dataByte, 0);
        fileName = Encoding.ASCII.GetString(dataByte, 4, fileNameLen);
        if (File.Exists(Program.loc + fileName))
            switch (MessageBox.Show("Ficheiro já existente!\r\nDeseja Substituir?", "Aviso", MessageBoxButtons.YesNo,
                MessageBoxIcon.Warning))
            {
                case DialogResult.Yes:
                    File.Delete(Program.loc + fileName);
                    download = true;
                    break;
                case DialogResult.No:
                    download = false;
                    break;
            }
        if (download)
        {
            Stream fileStream = File.OpenWrite(Program.loc + fileName);
            fileStream.Write(dataByte, 4 + fileNameLen, (1024 - (4 + fileNameLen)));
            bool progChanged = false;
            backWork.WorkerReportsProgress = true;
            double progAnt = 0;
            while (true)
            {
                qtd = networkStream.Read(dataByte, 0, blockSize);
                qtdDown += qtd;
                progress = (double)qtdDown * (double)100 / (double)size;
                if (Math.Round(progress) > Math.Round(progAnt))
                {
                    progChanged = true;
                    progAnt = progress;
                }
                if (Math.Round(progress) > 0 && progChanged)
                {
                    backWork.ReportProgress(((int)Math.Round(progress)));
                    progChanged = false;
                }
                fileStream.Write(dataByte, 0, qtd);
                fileStream.Flush();
                blocksDown++;
                if (qtd == 0)
                {
                    backWork.ReportProgress(100);
                    qtd = networkStream.Read(dataByte, 0, blockSize);
                    networkStream.Close();
                    fileStream.Close();
                    break;
                }
            }
            MessageBox.Show("O ficheiro " + fileName + " foi guardado em " + Program.loc + ".", "Download",
                MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    }
}

这就是我正在做的事情。我在后台工作者上下载。首先，我在流上写下我正在做的事情，然后打开文件流，然后开始读取流并写入文件。

@Ňuf我试过你所说的但仍然无法运作代码如下所示， qtdDown 和 size 中的字节不相等。很抱歉，如果有一些葡萄牙语部分，我的母语是葡萄牙语。

    btnAct.Enabled = false;
    btnBro.Enabled = false;
    btnDown.Enabled = false;
    btnSend.Enabled = false;
    menuStrip1.Enabled = false;
    pBar.Value = 0;
    clientSocket = new TcpClient(Program.host, Program.port);
    NetworkStream networkStream = clientSocket.GetStream();
    StreamWriter write = new StreamWriter(networkStream);
    write.WriteLine(need);
    write.Flush();
    write.WriteLine(loca);
    write.Flush();
    int blockSize = 1024;
    byte[] fileSizeBytes = new byte[blockSize];
    networkStream.Read(fileSizeBytes, 0, blockSize);
    string fileSizeString = Encoding.ASCII.GetString(fileSizeBytes, 0, fileSizeBytes.Length);
    fileSize = Convert.ToInt64(fileSizeString);
    qtdDown = 0;
    try
    {
        string fileName = string.Empty;
        int qtd = 0;
        double progress = 0;
        Byte[] dataByte = new Byte[blockSize];
        bool download = true;
        lock (this)
        {
            networkStream.Read(dataByte, 0, dataByte.Length);
            int fileNameLen = BitConverter.ToInt32(dataByte, 0);
            fileName = Encoding.ASCII.GetString(dataByte, 4, fileNameLen);
            if (File.Exists(Program.loc + fileName))
                switch (MessageBox.Show("Ficheiro já existente!\r\nDeseja Substituir?", "Aviso", MessageBoxButtons.YesNo,
                    MessageBoxIcon.Warning))
                {
                    case DialogResult.Yes:
                        File.Delete(Program.loc + fileName);
                        download = true;
                        break;
                    case DialogResult.No:
                        download = false;
                        break;
                }
            if (download)
            {
                Stream fileStream = File.OpenWrite(Program.loc + fileName);
                fileStream.Write(dataByte, 4 + fileNameLen, (1024 - (4 + fileNameLen)));
                networkStream.ReadTimeout = 60;
                backWork.WorkerReportsProgress = true;
                double progAnt = 0;
                while (true)
                {
                    qtd = networkStream.Read(dataByte, 0, blockSize);
                    qtdDown += qtd;
                    progress = (double)qtdDown * (double)100 / (double)fileSize;
                    if (Math.Round(progress) > Math.Round(progAnt))
                    {
                        progAnt = progress;
                        backWork.ReportProgress(((int)Math.Round(progress)));
                    }
                    fileStream.Write(dataByte, 0, qtd);
                    if (qtdDown == fileSize)
                    {
                        backWork.ReportProgress(100);
                        fileStream.Close();
                        networkStream.Close();
                        break;
                    }
                }
                MessageBox.Show("O ficheiro " + fileName + " foi guardado em " + Program.loc + ".", "Download",
                    MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }
    }

    catch (Exception ex)
    {
        menuStrip1.Enabled = true;
        btnAct.Enabled = true;
        btnBro.Enabled = true;
        btnDown.Enabled = true;
        btnSend.Enabled = true;
        MessageBox.Show("Ocorreu um erro!" + "\r\nBytes Downloaded: "
            + qtdDown.ToString() + "\\" + fileSize.ToString() + "\r\nDetalhes do Erro: " + ex.Message, "Download",
            MessageBoxButtons.OK, MessageBoxIcon.Error);
    }

    menuStrip1.Enabled = true;
    btnAct.Enabled = true;
    btnBro.Enabled = true;
    btnDown.Enabled = true;
    btnSend.Enabled = true;

Answer 1

通过调用read.ReadLine（）来丢失字节。虽然此函数仅返回来自一行的数据，但它在内部从网络流中读取更多数据到内部缓冲区，并为后续的read.Read（）调用保留剩余数据，这在您的代码中永远不会发生。

使用StreamReader读取数据或直接从NetworkStrem读取数据，但不要将两者的读数混合在一起。

Answer 2

我在最后的中添加了这一行，如果，* || （fileSize - qtdDown）＆lt; 1024 *和文件现在可以工作，我不知道那些最后的字节是否重要，但文件现在可以工作。

缺少文件的最后一个字节

2 个答案: