Send text file directly to network printer

问题:

I have currently-working code which sends raw data to a printer by writing a temporary file, then using File.Copy() to send it to the printer. File.Copy() supports both local ports, like LPT1 and shared printers like \\FRONTCOUNTER\LabelPrinter.

However, now I'm trying to get it working with a printer that's directly on the network: 192.168.2.100, and I can't figure out the format to use.

File.Copy(filename, @"LPT1", true); // Works, on the FRONTCOUNTER computer
File.Copy(filename, @"\\FRONTCOUNTER\LabelPrinter", true); // Works from any computer
File.Copy(filename, @"\\192.168.2.100", true); // New printer, Does not work

I know it's possible to "Add a printer" from each computer, but I'm hoping to avoid that - the second line of code above works from any computer on the network automatically, with no configuration required. I also know it's possible to P/Invoke the windows print spooler, and if that's my only option I may take it, but that's much more code overhead than I'd like to have.

Ideally, someone will have either a way to make File.Copy() work or a similar C# statement which will accept a network IP.

回答1:

You can use sockets and send the data straight to that IP address. Should pretty much be the same as File.Copy. I just tried it out and that worked.

I just sent some text but here is the code that I used

Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
clientSocket.NoDelay = true;

IPAddress ip = IPAddress.Parse("192.168.192.6");
IPEndPoint ipep = new IPEndPoint(ip, 9100);
clientSocket.Connect(ipep);

byte[] fileBytes = File.ReadAllBytes("test.txt");

clientSocket.Send(fileBytes);
clientSocket.Close();

回答2:

try this code:

public class PrintHelper
{
    private readonly IPAddress PrinterIPAddress;

    private readonly byte[] FileData;

    private readonly int PortNumber;
    private ManualResetEvent connectDoneEvent { get; set; }

    private ManualResetEvent sendDoneEvent { get; set; }

    public PrintHelper(byte[] fileData, string printerIPAddress, int portNumber = 9100)
    {
        FileData = fileData;
        PortNumber = portNumber;
        if (!IPAddress.TryParse(printerIPAddress, out PrinterIPAddress))
            throw new Exception("Wrong IP Address!");
    }

    public PrintHelper(byte[] fileData, IPAddress printerIPAddress, int portNumber = 9100) 
    {
        FileData = fileData;
        PortNumber = portNumber;
        PrinterIPAddress = printerIPAddress;
    }

    /// <inheritDoc />
    public bool PrintData()
    {
        //this line is Optional for checking before send data
        if (!NetworkHelper.CheckIPAddressAndPortNumber(PrinterIPAddress, PortNumber))
            return false;
        IPEndPoint remoteEP = new IPEndPoint(PrinterIPAddress, PortNumber);
        Socket client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        client.NoDelay = true;
        connectDoneEvent = new ManualResetEvent(false);
        sendDoneEvent = new ManualResetEvent(false);

        try
        {
            client.BeginConnect(remoteEP, new AsyncCallback(connectCallback), client);
            connectDoneEvent.WaitOne();
            client.BeginSend(FileData, 0, FileData.Length, 0, new AsyncCallback(sendCallback), client);
            sendDoneEvent.WaitOne();
            return true;
        }
        catch
        {
            return false;
        }
        finally
        {
            // Shutdown the client
            this.shutDownClient(client);
        }
    }

    private void connectCallback(IAsyncResult ar)
    {
        // Retrieve the socket from the state object.
        Socket client = (Socket)ar.AsyncState;

        // Complete the connection.
        client.EndConnect(ar);

        // Signal that the connection has been made.
        connectDoneEvent.Set();
    }

    private void sendCallback(IAsyncResult ar)
    {
        // Retrieve the socket from the state object.
        Socket client = (Socket)ar.AsyncState;

        // Complete sending the data to the remote device.
        int bytesSent = client.EndSend(ar);

        // Signal that all bytes have been sent.
        sendDoneEvent.Set();
    }
    private void shutDownClient(Socket client)
    {
        client.Shutdown(SocketShutdown.Both);
        client.Close();
    }
}

Network Helper class:

public static class NetworkHelper
    {
        public static bool CheckIPAddressAndPortNumber(IPAddress ipAddress, int portNumber)
        {
            return PingIPAddress(ipAddress) && CheckPortNumber(ipAddress, portNumber);
        }
        public static bool PingIPAddress(IPAddress iPAddress)
        {
            var ping = new Ping();
            PingReply pingReply = ping.Send(iPAddress);

            if (pingReply.Status == IPStatus.Success)
            {
                //Server is alive
                return true;
            }
            else
                return false;
        }
        public static bool CheckPortNumber(IPAddress iPAddress, int portNumber)
        {
            var retVal = false;
            try
            {
                using (TcpClient tcpClient = new TcpClient())
                {
                    tcpClient.Connect(iPAddress, portNumber);
                    retVal = tcpClient.Connected;
                    tcpClient.Close();
                }
                return retVal;
            }
            catch (Exception)
            {
                return retVal;
            }

        }
    }