我通过socket传binary文件，发送端读取文件并通过数据流发送给对端。对端接收时需要先申请一个字节数组，例如：
dim buffer（1024）as byte,但发送的数据没有1024这么大，例如发送了200字节，会导致1024中申请的内存过大，剩下的800多空间是没有用的，如何能够清除掉？vb.net在发送时不能标记结尾吗？
trim这类方法都试过了，行不通。求高人解决。
dim buffer（1024）as byte,但发送的数据没有1024这么大，例如发送了200字节，会导致1024中申请的内存过大，剩下的800多空间是没有用的，如何能够清除掉？vb.net在发送时不能标记结尾吗？
trim这类方法都试过了，行不通。求高人解决。
ProtocolType.Tcp);
IPEndPoint iep = new IPEndPoint(IPAddress.Any, 9050);
sock.Bind (iep);
sock.Listen (5);
sock.BeginAccept (new AsyncCallback(CallAccept), sock);private void CallAccept(IAsyncResult iar)
{
Socket server = (Socket)iar.AsyncState;
Socket client = server.EndAccept(iar);
}class Data
{
//Default constructor
public Data()
{
this.cmdCommand = Command.Null;
this.strMessage = null;
this.strName = null;
} //Converts the bytes into an object of type Data
public Data(byte[] data)
{
//The first four bytes are for the Command
this.cmdCommand = (Command)BitConverter.ToInt32(data, 0); //The next four store the length of the name
int nameLen = BitConverter.ToInt32(data, 4); //The next four store the length of the message
int msgLen = BitConverter.ToInt32(data, 8); //Makes sure that strName has been passed in the array of bytes
if (nameLen > 0)
this.strName = Encoding.UTF8.GetString(data, 12, nameLen);
else
this.strName = null; //This checks for a null message field
if (msgLen > 0)
this.strMessage = Encoding.UTF8.GetString(data,
12 + nameLen, msgLen);
else
this.strMessage = null;
} //Converts the Data structure into an array of bytes
public byte[] ToByte()
{
List<byte> result = new List<byte>(); //First four are for the Command
result.AddRange(BitConverter.GetBytes((int)cmdCommand)); //Add the length of the name
if (strName != null)
result.AddRange(BitConverter.GetBytes(strName.Length));
else
result.AddRange(BitConverter.GetBytes(0)); //Length of the message
if (strMessage != null)
result.AddRange(BitConverter.GetBytes(strMessage.Length));
else
result.AddRange(BitConverter.GetBytes(0)); //Add the name
if (strName != null)
result.AddRange(Encoding.UTF8.GetBytes(strName)); //And, lastly we add the message text to our array of bytes
if (strMessage != null)
result.AddRange(Encoding.UTF8.GetBytes(strMessage)); return result.ToArray();
} //Name by which the client logs into the room
public string strName;
//Message text
public string strMessage;
//Command type (login, logout, send message, etc)
public Command cmdCommand;
}TCP Server
//The ClientInfo structure holds
//the required information about every
//client connected to the server
struct ClientInfo
{
//Socket of the client
public Socket socket;
//Name by which the user logged into the chat room
public string strName;
}//The collection of all clients logged
//into the room (an array of type ClientInfo)
ArrayList clientList;//The main socket on which the server listens to the clients
Socket serverSocket;byte[] byteData = new byte[1024];Here is how it starts listening for the clients and accepts the incoming requests:private void Form1_Load(object sender, EventArgs e)
{
try
{
//We are using TCP sockets
serverSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Stream,
ProtocolType.Tcp);
//Assign the any IP of the machine and listen on port number 1000
IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Any, 1000); //Bind and listen on the given address
serverSocket.Bind(ipEndPoint);
serverSocket.Listen(4); //Accept the incoming clients
serverSocket.BeginAccept(new AsyncCallback(OnAccept), null);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "SGSserverTCP",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}Below is the corresponding OnAccept function:private void OnAccept(IAsyncResult ar)
{
try
{
Socket clientSocket = serverSocket.EndAccept(ar); //Start listening for more clients
serverSocket.BeginAccept(new AsyncCallback(OnAccept), null); //Once the client connects then start
//receiving the commands from her
clientSocket.BeginReceive(byteData, 0,
byteData.Length, SocketFlags.None,
new AsyncCallback(OnReceive), clientSocket);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "SGSserverTCP",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
TCP Client//The main client socket
public Socket clientSocket;
//Name by which the user logs into the room
public string strName;private byte[] byteData = new byte[1024];The client firstly connects to the server:try
{
//We are using TCP sockets
clientSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp); IPAddress ipAddress = IPAddress.Parse(txtServerIP.Text);
//Server is listening on port 1000
IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, 1000); //Connect to the server
clientSocket.BeginConnect(ipEndPoint,
new AsyncCallback(OnConnect), null);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "SGSclient",
MessageBoxButtons.OK,
MessageBoxIcon.Error);
}
//Broadcast the message typed by the user to everyone
private void btnSend_Click(object sender, EventArgs e)
{
try
{
//Fill the info for the message to be send
Data msgToSend = new Data();
msgToSend.strName = strName;
msgToSend.strMessage = txtMessage.Text;
msgToSend.cmdCommand = Command.Message; byteData = msgToSend.ToByte(); //Send it to the server
clientSocket.BeginSend (byteData, 0, byteData.Length,
SocketFlags.None,
new AsyncCallback(OnSend), null); txtMessage.Text = null;
}
catch (Exception)
{
MessageBox.Show("Unable to send message to the server.",
"SGSclientTCP: " + strName,
MessageBoxButtons.OK,
MessageBoxIcon.Error);
}
}