【发布时间】：2019-06-24 20:18:00
【问题描述】：
我对这段代码有一个严重的问题。这是它应该如何工作的： 客户端连接到服务器并选择磁盘上的文件。在该客户端以这种格式（“文件”（4字节）+ FileNameLength（4字节）+ FileDataLength（4字节））向服务器发送（字节[]缓冲区）之后。 在该服务器创建一个具有此大小（新字节[FileNameLength + FileDataLength]）的（字节[]缓冲区）之后，客户端以这种格式（字节[]缓冲区=文件名+文件数据）向服务器发送数据。服务器得到一个文件。问题出在这里，我在服务器中有一个 MessageBox 可以在接收到 FileName 后查看 FileName，但 MessageBox 始终为空白，并且它运行时间和时间。 有什么解决办法？
服务器：
private Socket SServer = null;
private Socket SClient = null;
private byte[] buffer = new byte[1024];
private byte[] FileNameLength = null;
private byte[] FileSize = null;
private void Server_Load(object sender, EventArgs e)
{
SServer = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
SServer.Bind(new IPEndPoint(IPAddress.Parse("127.0.0.1"), 13000));
SServer.Listen(1);
new Thread(() =>
{
SClient = SServer.Accept();
MessageBox.Show("Connected.");
new Thread(() => Receiver()).Start();
}).Start();
}
private void Receiver()
{
buffer = new byte[1024];
while (true)
{
Int32 AllLength = SClient.Receive(buffer, 0, buffer.Length, SocketFlags.None);
byte[] Devider = new byte[4];
Array.Copy(buffer, 0, Devider, 0, 4);
string Devide = Encoding.ASCII.GetString(Devider);
if (AllLength > 0)
{
if (Devide == "File")
{
FileNameLength = new byte[4];
Array.Copy(buffer, 4, FileNameLength, 0, 4);
FileSize = new byte[4];
Array.Copy(buffer, 8, FileSize, 0, 4);
buffer = null;
buffer = new byte[BitConverter.ToInt32(FileNameLength, 0) + BitConverter.ToInt32(FileSize, 0)];
}
else
{
byte[] FileNameBytes = new byte[BitConverter.ToInt32(FileNameLength, 0)];
Array.Copy(buffer, 0, FileNameBytes, 0, BitConverter.ToInt32(FileNameLength, 0));
byte[] FileBytes = new byte[BitConverter.ToInt32(FileSize, 0)];
Array.Copy(buffer, BitConverter.ToInt32(FileNameLength, 0), FileBytes, 0, BitConverter.ToInt32(FileBytes, 0));
string FileName = Encoding.ASCII.GetString(FileNameBytes);
MessageBox.Show(FileName);
buffer = null;
buffer = new byte[1024];
}
}
}
}
客户：
private Socket SClient = null;
string Path, FileName;
private void Client_Load(object sender, EventArgs e)
{
SClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
SClient.Connect(new IPEndPoint(IPAddress.Parse("127.0.0.1"), 13000));
}
private void BT_SendFile_Click(object sender, EventArgs e)
{
byte[] FileLengthBytes = BitConverter.GetBytes(FileName.Length);
byte[] FileBytes = File.ReadAllBytes(Path + FileName);
byte[] buffer = new byte[FileLengthBytes.Length + FileBytes.Length + 4];
//buffer = Encoding.Unicode.GetBytes("File") + FileLengthBytes + FileBytes;
Array.Copy(Encoding.ASCII.GetBytes("File"), 0, buffer, 0, 4);
Array.Copy(FileLengthBytes, 0, buffer, 4, FileLengthBytes.Length);
Array.Copy(BitConverter.GetBytes(FileBytes.Length), 0, buffer, 8, 4);
SClient.Send(buffer, 0, buffer.Length, SocketFlags.None);
byte[] FileNameBytes = Encoding.ASCII.GetBytes(FileName);
buffer = null;
buffer = new byte[FileNameBytes.Length + FileBytes.Length];
Array.Copy(FileNameBytes, 0, buffer, 0, FileNameBytes.Length);
Array.Copy(FileBytes, 0, buffer, FileNameBytes.Length, FileBytes.Length);
SClient.Send(buffer, 0, buffer.Length, SocketFlags.None);
}
private void BT_Browse_Click(object sender, EventArgs e)
{
OpenFileDialog N = new OpenFileDialog();
if (N.ShowDialog() == DialogResult.OK)
{
TB_Address.Text = N.FileName;
string[] Seperate = N.FileName.Split('\\');
FileName = Seperate[Seperate.Length - 1];
Path = null;
foreach (string str in Seperate)
{
if (str != Seperate[Seperate.Length - 1])
Path += str + "\\";
}
}
}
【问题讨论】：
-
你不会在一个块中获得整个接收消息 TCP 的最大数据报大小约为 1500 字节。您的文件可能要大得多。所以你只需要从初始块中删除文件名和大小。尝试自己调试并确保正确提取文件名和大小以及文件的第一块。这是您在 CS 101 Basket Weaving 中进行的非常基本的调试。
-
既然有FTP、FTPs, SFTP、SCP、...，为什么还要重新发明轮子？
标签： c# sockets tcp protocols sendfile