How to Solve System.FormatException??

问题

Tell me how to fix this Exception please, when the transfer occurs between the PC.

Exception Thrown :

(System.FormatException)

A System.FormatException was thrown: "Input string had an incorrect format."

In Line :

fileSize = Convert.ToInt32(Encoding.UTF8.GetString(byteFileSize));

My whole Code :

private void Server()
{
    FileStream fs = null;
    BinaryWriter bw = null;
    int fileSize = 0;
    int bytesReceived = 0;
    int bufferInt = Int32.Parse(textBoxBYTE2.Text);

    byte[] bufferByte = new byte[bufferInt];
    byte[] byteFileName = Encoding.UTF8.GetBytes("empty");
    byte[] byteFileSize = Encoding.UTF8.GetBytes("empty");

    string fileName = "";

    int bytesTmp = 0;

    try
    {   
        IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Parse(ServerIP), int.Parse(textBoxPORT1.Text));
        Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp );
        socket.Bind(localEndPoint);
        socket.Listen(10);
        Socket listener = socket.Accept();
        //[1] Принимаем имя
        bytesTmp = listener.Receive(byteFileName);
        fileName = Encoding.UTF8.GetString(byteFileName, 0, bytesTmp);
        //[2] Принимаем размер
        listener.Receive(byteFileSize);

        fileSize = Convert.ToInt32(Encoding.UTF8.GetString(byteFileSize)); //Exception Thrown Here

        fs = new FileStream(Path.Combine(textBoxPATH.Text, fileName), FileMode.CreateNew, FileAccess.Write);
        bw = new BinaryWriter(fs);
        //<!--
        while (bytesReceived < fileSize)
        {
            if ((fileSize - bytesReceived) < bufferInt)
            {
                int bytes = (fileSize - bytesReceived);
                byte[] buf = new byte[bytes];
                bytes = listener.Receive(buf);
                bw.Write(buf, 0, bytes);
                bytesReceived = bytesReceived + bytes;
            } else {
                int bytes = listener.Receive(bufferByte);
                bw.Write(bufferByte, 0, bytes);
                bytesReceived = bytesReceived + bytes;
            }
        }
        //-->
        //Закрытие
        bw.Close();
        socket.Close();
        listener.Close();
    }
    catch (Exception e)
    {
        System.Windows.Forms.MessageBox.Show("" + e, "Сервер сообщает");
    }
}
private void Client()
{
    FileStream fs = null;
    BinaryReader br = null;
    int bytesSent = 0;
    int fileSize = 0;            
    int bufferInt = Int32.Parse(textBoxBYTE2.Text);
    byte[] bufferByte = new byte[bufferInt];
    byte[] byteFileName = new byte[512];
    byte[] byteFileSize = new byte[512];
    string fileName = "";

    try
    {
        Socket sender = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        sender.Connect(textBoxADDRESS2.Text, int.Parse(textBoxPORT2.Text));
        FileInfo fileInfo = new FileInfo(textBoxFILE.Text);
        fileName = fileInfo.Name;
        byteFileName = Encoding.UTF8.GetBytes(fileName);
        //[1] Передаем имя
        sender.Send(byteFileName);
        fs = new FileStream(textBoxFILE.Text, FileMode.Open);
        br = new BinaryReader(fs);
        fileSize = (int) fs.Length;
        byteFileSize = Encoding.UTF8.GetBytes(Convert.ToString(fileSize));
        //[2] Передаем размер файла
        sender.Send(byteFileSize);
        //<!--
        while (bytesSent < fileSize)
        {
            if ((fileSize - bytesSent) < bufferInt)
            {
                int bytes = (fileSize - bytesSent);
                byte[] buf = new byte[bytes];
                br.Read(buf, 0, bytes);
                sender.Send(buf);
                bytesSent = bytesSent + bytes;
            } else {
               br.Read(bufferByte, 0, bufferInt);
               sender.Send(bufferByte);
               bytesSent = bytesSent + bufferInt;
            } 
        }
        //-->
        //Закрытие
        br.Close();
        sender.Close();
    }
    catch (Exception e)
    {
        System.Windows.Forms.MessageBox.Show("" + e, "Клиент сообщает");
    }
}

回答1:

In your call to Socket.Receive, you're ignoring how many bytes are actually read.

That raises two problems:

How do you know when you've read enough?
You're currently assuming that all of the byte array contains useful data, whereas some of it may well be the "old" data.

回答2:

It seems to me that you should be calling

fileSize = byteFileSize.Length;

Since byteFileSize is a byte[]

来源：https://stackoverflow.com/questions/10702431/how-to-solve-system-formatexception

标签

sockets

formatexception