我已经尝试了我能找到的所有解决方案，但似乎没有任何效果。除文本文件之外的任何内容都会损坏;有人说TCP不能发送超过8KB，所以我试图解决问题，我想我做了。现在，当我发送一个文本文件（无论它的大小）时，它完全达到但其他任何东西都被破坏了。我知道切割的代码性能很昂贵，但我稍后会考虑这个。
这是我的发件人代码：
private string SendFile(string tosend, string tosendname)
{
ipadd = IPAddress.Parse(textBox2.Text);
ep = new IPEndPoint(ipadd, 6112);
Sender = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
Sender.Connect(ep);
Thread.Sleep(100);
byte[] filetosend = System.IO.File.ReadAllBytes(tosend);
FileStream fs = new FileStream(tosend, FileMode.Open, FileAccess.Read);
//Read byte from image
fs.Read(filetosend, 0, filetosend.Length);
fs.Flush();
fs.Close();
int countt = filetosend.Count();
int dividedcount = countt / 7000;
Sender.Send(Encoding.ASCII.GetBytes("filesize#" + filetosend.Count().ToString()));
Thread.Sleep(500);
List<byte> cuttedtosend = new List<byte>();
for (int counti = 0; counti < dividedcount; counti++)
{
cuttedtosend = new List<byte>();
for (int index = 0; index < 7000; index++)
{
cuttedtosend.Add(filetosend[(filetosend.Count() - countt) + index]);
}
Sender.Send(cuttedtosend.ToArray());
Thread.Sleep(100);
countt -= 7000;
richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText("Countt = " + countt + "\n"); });
richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText("Counti = " + counti + "\n"); });
}
richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText("Done"); });
cuttedtosend = new List<byte>();
for (int index = filetosend.Count() - countt; index < filetosend.Count(); index++)
{
//richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText(index + "this is 2 \n"); });
cuttedtosend.Add(filetosend[index]);
}
Sender.Send(cuttedtosend.ToArray());
countt -= countt;
return "";
}
这是我的接收代码：
private async void StartReceiving()
{
List<byte> neededbytes = new List<byte>();
receivedbyte = new byte[InputForm.s];
Receiver.Bind(new IPEndPoint(IPAddress.Parse("0"), 6112));
Receiver.Listen(1000);
string filename = "Downloadedfile";
bool cont = false;
while (true)
{
Client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
Client = Receiver.Accept();
int filesize = 0;
byte[] receivechecker = new byte[100];
Client.Receive(receivechecker);
if(Encoding.ASCII.GetString(receivechecker).Contains("filesize#"))
{
filesize = Convert.ToInt32(Encoding.ASCII.GetString(receivechecker).Remove(0, 9));
Client.Receive(receivechecker);
}
if (Encoding.ASCII.GetString(receivechecker).Contains("#100254#"))
{
string[] splttedtext = Encoding.ASCII.GetString(receivechecker.ToArray()).Split('#');
if (splttedtext[0] == "mess")
{
MessageBox.Show(splttedtext[2]);
}
else if (splttedtext[0] == "filename")
{
//MessageBox.Show(splttedtext[2]);
filename = splttedtext[2];
//filename.Replace(@"\", @"/");
cont = true;
}
}
else
{
List<byte> tosave = new List<byte>();
richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText(filesize.ToString() + "\n"); });
int countt = filesize / 7000;
FileStream writer = File.Create("DownloadedFile.jpg");
for (int counti = 0; counti < countt; counti++)
{
byte[] toadd = new byte[7000];
richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText("Counti = " + counti.ToString() + "\n"); });
Client.Receive(toadd);
writer.Write(toadd,0,toadd.Count());
neededbytes.AddRange(toadd);
filesize -= 7000;
}
richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText(filesize.ToString() + "\n"); });
byte[] toadds = new byte[filesize];
Client.Receive(toadds);
writer.Write(toadds,0,toadds.Count());
writer.Close();
neededbytes.AddRange(toadds);
filesize -= filesize;
}
}
提前致谢：D
编辑： 我刚尝试发送一个7mb的文本文件，它已经完成.......
答案 0 :(得分：3)
最直接的问题是你要保存你不一定收到的字节。例如，您有：
for (int counti = 0; counti < countt; counti++)
{
byte[] toadd = new byte[7000];
richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText("Counti = " + counti.ToString() + "\n"); });
Client.Receive(toadd);
writer.Write(toadd,0,toadd.Count());
neededbytes.AddRange(toadd);
filesize -= 7000;
}
Receive的文档说该方法将接收最多您请求的字节数。它返回的字节数少于您请求的字节数，这种情况并不少见，尤其是在文件末尾（因为文件长度不能超过文件长度）。
你需要写：
var bytesRead = Client.Receive(toadd);
writer.Write(toadd, 0, bytesRead); // only write as many bytes as you've read
一般来说，您的代码非常复杂，您还有其他几个可能的问题等着咬你。例如，发送文件大小的代码会休眠500毫秒，这恰好足以让接收器只读取发送的字节数。没有那个睡眠，你的代码就会失败。
您有代码来接收文件名，但没有代码可以发送它。
我建议您删除ASCII标记并以二进制形式发送内容。以下是您重写的发送方法。
private string SendFile(string tosend, string tosendname)
{
ipadd = IPAddress.Parse(textBox2.Text);
ep = new IPEndPoint(ipadd, 6112);
Sender = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
Sender.Connect(ep);
byte[] filetosend = System.IO.File.ReadAllBytes(tosend);
byte[] filesizeBytes = BitConverter.GetBytes(filetosend.Length);
Sender.Send(filesizeBytes); // sends the length as an integer
// note: You could use Socket.Send(filetosend) here.
// but I'll show an example of sending in chunks.
int totalBytesSent = 0;
while (totalBytesSent < filetosend.Length)
{
int bytesLeft = filetosend.Length - totalBytesSent;
int bytesToSend = Math.Min(bytesLeft, 7000);
Sender.Send(filetosend, totalBytesSent, bytesToSend);
richTextBox1.Invoke((MethodInvoker)delegate
{ richTextBox1.Append(totalBytesSent + " bytes sent\n"); });
totalBytesSent += bytesToSend;
}
richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText("Done"); });
return "";
}
接收器代码同样简化：
private async void StartReceiving()
{
Receiver.Bind(new IPEndPoint(IPAddress.Parse("0"), 6112));
Receiver.Listen(1000);
string filename = "Downloadedfile";
bool cont = false;
while (true)
{
Client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
Client = Receiver.Accept();
// read the length
byte[] filesizeBytes = new byte[4];
int totalBytesReceived = 0;
while (totalBytesReceived < 4)
{
int bytesRead = Client.Receive(
filesizeBytes, totalBytesReceived, 4-totalBytesReceived);
totalBytesReceived += bytesRead;
}
int filesize = BitConverter.ToInt32(filesizeBytes);
richTextBox1.Invoke((MethodInvoker)delegate
{ richTextBox1.AppendText(filesize.ToString() + "\n"); });
// now read the file
using (FileStream writer = File.Create("DownloadedFile.jpg"))
{
byte[] readBuffer = new byte[7000];
totalBytesReceived = 0;
while (totalBytesReceived < filesize)
{
int bytesToRead = Math.Min(7000, filesize - totalBytesReceived);
int bytesRead = Client.Receive(readBuffer, 0, bytesToRead);
totalBytesRead += bytesRead;
writer.Write(readBuffer, 0, bytesRead);
richTextBox1.Invoke((MethodInvoker)delegate
{ richTextBox1.AppendText("Read " + bytesRead.ToString() + "bytes\n"); });
}
richTextBox1.Invoke((MethodInvoker)delegate
{ richTextBox1.AppendText("Done. " + totalBytesRead.ToString() + " bytes\n"); });
}
}
如果你想发送文件名，那么我建议将其转换为UTF8（Encoding.UTF8.GetBytes(filename)），然后发送一个int（4字节），说明它有多长，然后是缓冲区。要接收它，请阅读4字节文件名长度，就像我展示了如何读取文件大小，然后读取文件名的那么多字节，然后转换回字符串（Encoding.UTF8.GetString(bytes, 0, filenameLength)）。
请原谅代码中的任何拼写错误或小错误。我是从记忆中做到这一点，并试图保持一定的编码风格。
答案 1 :(得分：1)
我怀疑你期待收到的同一个区块被收到;即将保留记录边界。事实并非如此。 TCP保证将接收发送的每个字节并保留该顺序;但你可以做1个大10k发送和接收10k 1字节消息。