Question

这是使用套接字TCP的文件传输发送/接收程序。此代码包含在客户端和服务器应用程序中，并且它仅在第一次正常工作。

第二次，将要接收的一方获得0并且转移结束。如何修复它以便可以多次使用？

public static void sendFile(string filePath)
{
    FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read);
    string fileName = Path.GetFileName(filePath);
    byte[] fileData;
    try
    {
        //sending file name and file size to the server
        busy = true;
        fileSize = fs.Length;
        byte[] fileDetial = null;
        string detail =  fileName + "," + fileSize.ToString();
        fileDetial = Encoding.ASCII.GetBytes(detail);
        client.Send(fileDetial);

        //sending file data to the server

        fileData = new byte[packetSize];
        count = 0;
        sum = 0;
        Program.thFP.Start();                           // running transfer rate
        Program.fp.StatusLabel("Sending data...");
        transferRate.timeLeft();

        while (sum < fileSize)
        {
            fs.Seek(sum, SeekOrigin.Begin);
            fs.Read(fileData, 0, fileData.Length);
            count = client.Send(fileData, 0, fileData.Length, SocketFlags.None);
            sum += count;
            Program.fp.ProgressBarFileHandler(sum, fileSize);
        }
    }
    finally
    {
        busy = false;
        fs.Close();
        fileData = null;
        MessageBox.Show(string.Format("{0} sent successfully", fileName));
    }
}

根据我的猜测，下面的代码完全没有问题..我认为问题出在SENDFILE方法中..但是这里是receiveFile代码..它可能有帮助

public static void ReceiveFile()
{

    //receving file name and file size from server
    busy = true;
    byte[] commandData = new byte[1024];
    client.Receive(commandData);
    Console.WriteLine(Encoding.ASCII.GetString(commandData));
    string[] Command = Encoding.ASCII.GetString(commandData).Split(',');
    string fileName = Command[0];
    fileSize = Convert.ToInt64(Command[1]);
    Program.thFP.Start();                           // running transfer rate
    Program.fp.StatusLabel("Receiving data...");
    transferRate.timeLeft();

    // receiving the file data from server
    FileStream fs = new FileStream(@"D:\" + fileName, FileMode.Create, FileAccess.Write);
    byte[] fileData = new byte[packetSize];
    try
    {
        count = 0;
        sum = 0;
        while (sum < fileSize)
        {
            count = client.Receive(fileData,0,fileData.Length, SocketFlags.None);
            fs.Seek(sum, SeekOrigin.Begin);
            fs.Write(fileData, 0, fileData.Length);
            sum += count;
            Program.fp.ProgressBarFileHandler(sum,fileSize);
        }
    }
    finally
    {
        busy = false;
        fs.Close();
        fileData = null;
        MessageBox.Show(string.Format("{0} recevied successfully", fileName));
    }
}

Answer 1

我修好了代码。问题出在SendFile方法中，完全在FileStream

中

我应该处理它，所以我可以使用新路径再次初始化它

finally
{
    busy = false;
    fs.Dispose();   //here i fixed my mistake it was fs.Close()
    fileData = null;
    MessageBox.Show(string.Format("{0} sent successfully", fileName));
}

Answer 2

我建议你需要处理FileStream。我建议将它包装在一个使用块中，因此即使抛出一个重复也会一直处理它。

// receiving the file data from server
using (FileStream fs = new FileStream(@"D:\" + fileName, FileMode.Create, FileAccess.Write))
{
    byte[] fileData = new byte[packetSize];
    try
    {
        ...same code as before here...
    }
    finally
    {
         ...same code as before here...
    }
}

我总是建议在使用块中包装流。这意味着如果您以后再回来编辑代码，那么引入代码路径的危险就会降低，该代码路径在完成后不会丢弃流。

我还要重构代码，以便你的“成功”消息不在finally块中 - 它可能应该在try块的末尾。当抛出异常时，您当前的实现将显示Success消息 - 因此文件可能会成功。

文件传输仅在第一次成功，经常失败

2 个答案: