我使用套接字连接创建了一个服务器和一个客户端进行文件传输.我面临的问题是,如果收到的文件大小超过8KB,则该文件不完整.
如果你遇到这个问题,你可以指导我找出我做错了什么(在服务器/客户端)？
以下是两种方法:
客户:
#region FILE TRANSFER USING C#.NET SOCKET - CLIENT
class FTClient
{
public static string curMsg_client = "Idle";
public static void SendFile(string fileName)
{
try
{
//IPAddress[] ipAddress = Dns.GetHostAddresses("localhost");
//IPEndPoint ipEnd = new IPEndPoint(ipAddress[0], 5656);
string IpAddressString = "192.168.1.102";
IPEndPoint ipEnd_client = new IPEndPoint(IPAddress.Parse(IpAddressString), 5656);
Socket clientSock_client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
string filePath = "";
fileName = fileName.Replace("\\", "/");
while (fileName.IndexOf("/") > -1)
{
filePath += fileName.Substring(0, fileName.IndexOf("/") + 1);
fileName = fileName.Substring(fileName.IndexOf("/") + 1);
}
byte[] fileNameByte = Encoding.UTF8.GetBytes(fileName);
if (fileNameByte.Length > 5000 * 1024)
{
curMsg_client = "File size is more than 5Mb, please try with small file.";
return;
}
curMsg_client = "Buffering ...";
string fullPath = filePath + fileName;
byte[] fileData = File.ReadAllBytes(fullPath);
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);
curMsg_client = "Connection to server ...";
clientSock_client.Connect(ipEnd_client);
curMsg_client = "File sending...";
clientSock_client.Send(clientData, 0, clientData.Length, 0);
curMsg_client = "Disconnecting...";
clientSock_client.Close();
curMsg_client = "File [" + fullPath + "] transferred.";
}
catch (Exception ex)
{
if (ex.Message == "No connection could be made because the target machine actively refused it")
curMsg_client = "File Sending fail. Because server not running.";
else
curMsg_client = "File Sending fail." + ex.Message;
}
}
}
#endregion
和服务器:
#region FILE TRANSFER USING C#.NET SOCKET - SERVER
class FTServer
{
IPEndPoint ipEnd_server;
Socket sock_server;
public FTServer()
{
//make IP end point to accept any IP address with port 5656
//these values will be altered depending on ******* (and/or other ImportSystem)
//this was initially coded, but threw a SocketException on sock.Bind(ipEnd) {Only one usage of each socket address (protocol/network addres/port) is normally permitted}
//ipEnd = new IPEndPoint(IPAddress.Any, 5656);
//
//I'll set it like this (giving the IP through a string)
string IpAddressString = "192.168.1.102";
ipEnd_server = new IPEndPoint(IPAddress.Parse(IpAddressString), 5656);
//
//creating new socket object with protocol type and transfer data type
sock_server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
//bind end point with newly created socket
sock_server.Bind(ipEnd_server);
}
public static string receivedPath = @"C:\Users\Adrian.Constantin\Desktop\Simulare_Forder_Import\";
public static string curMsg_server = "Stopped!";
public void StartServer()
{
try
{
curMsg_server = "Starting...";
sock_server.Listen(100);
curMsg_server = "Running and waiting to receive file.";
Socket clientSock = sock_server.Accept();
byte[] clientData = new byte[512000];
int receivedBytesLen = clientSock.Receive(clientData, SocketFlags.None);
clientSock.ReceiveBufferSize = 8192;
curMsg_server = "Receiving data...";
int fileNameLen = BitConverter.ToInt32(clientData, 0);
string fileName = Encoding.UTF8.GetString(clientData, 4, fileNameLen);
BinaryWriter bWrite = new BinaryWriter(File.Open(receivedPath + "/" + fileName, FileMode.OpenOrCreate)); ;
bWrite.Write(clientData, 4 + fileNameLen, receivedBytesLen - 4 - fileNameLen);
curMsg_server = "Saving file...";
bWrite.Close();
clientSock.Close();
curMsg_server = "Received and Archived file [" + fileName + "]; Server stopped.";
}
catch (SocketException ex)
{
curMsg_server = "File Receving error.";
MessageBox.Show(String.Format("{0} Error cide: {1}", ex.Message, ex.ErrorCode));
}
}
}
#endregion
编辑:24.08.2012(我设法找出问题并让服务器工作)服务器的完整代码是: SERVER:
#region FILE TRANSFER USING C#.NET SOCKET - SERVER
class FTServer
{
IPEndPoint ipEnd_server;
Socket sock_server;
public FTServer()
{
string IpAddressString = "192.168.1.102";
ipEnd_server = new IPEndPoint(IPAddress.Parse(IpAddressString), 5656);
sock_server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
sock_server.Bind(ipEnd_server);
}
public static string receivedPath = @"C:\";
public static string curMsg_server = "Stopped!";
public void StartServer()
{
try
{
curMsg_server = "Starting...";
sock_server.Listen(100);
curMsg_server = "Running and waiting to receive file.";
Socket clientSock = sock_server.Accept();
clientSock.ReceiveBufferSize = 16384;
byte[] clientData = new byte[1024 * 50000];
int receivedBytesLen = clientSock.Receive(clientData, clientData.Length, 0);
curMsg_server = "Receiving data...";
int fileNameLen = BitConverter.ToInt32(clientData, 0);
string fileName = Encoding.UTF8.GetString(clientData, 4, fileNameLen);
BinaryWriter bWrite = new BinaryWriter(File.Open(receivedPath + fileName, FileMode.Append));
bWrite.Write(clientData, 4 + fileNameLen, receivedBytesLen - 4 - fileNameLen);
while (receivedBytesLen > 0)
{
receivedBytesLen = clientSock.Receive(clientData, clientData.Length, 0);
if (receivedBytesLen == 0)
{
bWrite.Close();
}
else
{
bWrite.Write(clientData, 0, receivedBytesLen);
}
}
curMsg_server = "Saving file...";
bWrite.Close();
clientSock.Close();
curMsg_server = "Received and Archived file [" + fileName + "] (" + (receivedBytesLen - 4 - fileNameLen) + " bytes received); Server stopped.";
}
catch (SocketException ex)
{
curMsg_server = "File Receving error.";
MessageBox.Show(String.Format("{0} Error code: {1}", ex.Message, ex.ErrorCode));
}
}
}
#endregion
你已经陷入了最经典的套接字使用陷阱.这个与伯克利开发的插座概念一样古老.
你看,你还没有看过文档:)
例如,请参阅http://msdn.microsoft.com/en-us/library/ms145160.aspx - 返回值是多少？
发送和接收方法都没有义务实际发送/接收您提供的所有数据.这就是为什么他们都返回一个'int'来描述实际发送/接收的数量.由于系统的内部缓冲区有限,因此保留了此设计.如果你提供一个999GB的数组要发送,你的网卡在实际发送之前将如何存储？
您看到8KB阈值的行为,可能是因为这是内部缓冲区的大小,或者可能是TCP网络数据包的最大大小.我不记得它们有多大,但它是围绕着这个.
要正确地发送和接收数据,您必须使用某种循环,例如,以简化形式:
int bytesToBeSent = arr.Length;
int bytesActuallySent = 0;
while(bytesActuallySent < bytesToBeSent)
bytesActuallySent += socket.Send(arr, bytesActuallySent, bytesToSend - bytesActuallySent, ....);
和recv - 类似.