poc-misc/LinePrinterPoC/LinePrinter.cs

/*
 *  LPrinter - A simple line printer class in C#
 *  ============================================
 *
 *  Written by Antonino Porcino, iz8bly@yahoo.it
 *
 *  26-sep-2008, public domain.
 *
 *
 *  some useful print codes:
 *  ========================
 *    12 = FF (form feed)
 *    14 = enlarged on
 *    20 = enlarged off
 *    15 = compress on
 *    18 = compress off
 *    ESC + "E" = bold on
 *    ESC + "F" = bold off
 */

using System;
using System.Drawing.Printing;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;

namespace LinePrinterPoC
{
    internal class LinePrinter
    {
        // Structure and API declarions:
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public class DOCINFOA
        {
            [MarshalAs(UnmanagedType.LPStr)]
            public string pDocName;

            [MarshalAs(UnmanagedType.LPStr)]
            public string pOutputFile;

            [MarshalAs(UnmanagedType.LPStr)]
            public string pDataType;
        }

        [DllImport("winspool.Drv", EntryPoint = "OpenPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, IntPtr pd);

        [DllImport("winspool.Drv", EntryPoint = "ClosePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool ClosePrinter(IntPtr hPrinter);

        [DllImport("winspool.Drv", EntryPoint = "StartDocPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool StartDocPrinter(IntPtr hPrinter, int level, [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di);

        [DllImport("winspool.Drv", EntryPoint = "EndDocPrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool EndDocPrinter(IntPtr hPrinter);

        [DllImport("winspool.Drv", EntryPoint = "StartPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool StartPagePrinter(IntPtr hPrinter);

        [DllImport("winspool.Drv", EntryPoint = "EndPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool EndPagePrinter(IntPtr hPrinter);

        [DllImport("winspool.Drv", EntryPoint = "WritePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, int dwCount, out int dwWritten);

        /*=================================================*/

        private IntPtr HandlePrinter;
        private PrinterSettings ps;

        public LinePrinter()
        {
            HandlePrinter = IntPtr.Zero;
            ps = new PrinterSettings();
        }

        public string PrinterName
        {
            get
            {
                return ps.PrinterName;
            }
            set
            {
                ps.PrinterName = value;
            }
        }

        public bool ChoosePrinter(IWin32Window parent = null)
        {
            var pd = new PrintDialog
            {
                PrinterSettings = ps
            };

            if (pd.ShowDialog(parent) != DialogResult.OK)
                return false;

            ps = pd.PrinterSettings;
            return true;
        }

        public bool Open(string docName)
        {
            // see if printer is already open
            if (HandlePrinter != IntPtr.Zero) return false;

            // opens the printer
            var risp = OpenPrinter(ps.PrinterName, out HandlePrinter, IntPtr.Zero);
            if (risp == false) return false;

            // starts a print job
            var docInfo = new DOCINFOA
            {
                pDocName = docName,
                pOutputFile = null,
                pDataType = "RAW"
            };

            if (!StartDocPrinter(HandlePrinter, 1, docInfo))
                return false;

            StartPagePrinter(HandlePrinter); //starts a page
            return true;
        }

        public bool Close()
        {
            if (HandlePrinter == IntPtr.Zero) return false;
            if (!EndPagePrinter(HandlePrinter)) return false;
            if (!EndDocPrinter(HandlePrinter)) return false;
            if (!ClosePrinter(HandlePrinter)) return false;
            HandlePrinter = IntPtr.Zero;
            return true;
        }

        public bool Print(string outputstring)
        {
            if (HandlePrinter == IntPtr.Zero) return false;
            IntPtr buf = Marshal.StringToCoTaskMemAnsi(outputstring);

            Int32 done;
            bool ok = WritePrinter(HandlePrinter, buf, Encoding.Default.GetByteCount(outputstring), out done);

            Marshal.FreeCoTaskMem(buf);

            return ok;
        }
    }
}