narsil/Tanshu.Accounts.Print/PrinterWindows.cs

using System;
using System.Runtime.InteropServices;

namespace Tanshu.Accounts.Print
{
    internal class PrinterWindows : PlatformPrinter
    {
        private string location;
        // Cut Code for the printer Alt-29, Alt-86, Alt-49
        #region API Declarations
        // Structure and API declarions:
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        internal 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)]
        internal 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)]
        internal static extern bool ClosePrinter(IntPtr hPrinter);

        [DllImport("winspool.drv", EntryPoint = "StartDocPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        internal static extern bool StartDocPrinter(IntPtr hPrinter, Int32 level, [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di);

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

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

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

        [DllImport("winspool.drv", EntryPoint = "WritePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
        internal static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, out Int32 dwWritten);
        #endregion
        internal PrinterWindows (string location)
        {
            this.location = location.Substring(4).Normalize();
        }
        internal override bool Print(string documentName, string printingText)
        {
            IntPtr hPrinter = new IntPtr(0);
            // The printer handle.
            // Last error -incase there was trouble.
            DOCINFOA di = new DOCINFOA();
            // Describes your document(name, port, data type).
            var bSuccess = false; // Your success code.

            // Set up the DOCINFO structure. 
            di.pDocName = documentName;
            di.pDataType = "RAW";

            if (OpenPrinter(location, out hPrinter, IntPtr.Zero))
            {
                if (StartDocPrinter(hPrinter, 1, di))
                {
                    if (!StartPagePrinter(hPrinter))
                        return false;
                    //Write your printer - specific bytes to the printer.
                    bSuccess = SendLine(printingText, hPrinter);
                    EndPagePrinter(hPrinter);
                    EndDocPrinter(hPrinter);
                }
                ClosePrinter(hPrinter);
            }
            // If you did not succeed, GetLastError may give more information about why not.
            if (bSuccess == false)
            {
                Marshal.GetLastWin32Error();
            }
            return bSuccess;
        }// SendBytesToPrinter()
            
        internal static bool SendLine(string szString, IntPtr hPrinter)
        {
            Int32 dwWritten = 0;
            Int32 dwCount = szString.Length; // How many characters are in the string?

            IntPtr pBytes = Marshal.StringToCoTaskMemAnsi(szString);
            // Assume that the printer is expecting ANSI text, and then convert
            // the string to ANSI text.

            // Write your bytes.
            return WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
        }
    }
}