using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;

namespace UAS_Web.tool
{
    class PrintHelper
    {
      
        // 结构和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, Int32 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, Int32 dwCount, out Int32 dwWritten);

        // SendBytesToPrinter()
        //当函数是给定一个打印机名称和一个非托管数组
        // 如果执行成功,将返回true;如果执行失败将返回false
        public static bool SendBytesToPrinter(string szPrinterName, IntPtr pBytes, Int32 dwCount)
        {
            Int32 dwError = 0, dwWritten = 0;
            IntPtr hPrinter = new IntPtr(0);
            DOCINFOA di = new DOCINFOA();
            bool bSuccess = false; // 假设失败.

            di.pDocName = "My C#.NET RAW Document";
            di.pDataType = "RAW";

            // 打开打印机
            if (OpenPrinter(szPrinterName.Normalize(), out hPrinter, IntPtr.Zero))
            {
                // 开始一个文档.
                if (StartDocPrinter(hPrinter, 1, di))
                {
                    // 创建新页面
                    if (StartPagePrinter(hPrinter))
                    {
                        // 写你的字节
                        bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
                        EndPagePrinter(hPrinter);
                    }
                    EndDocPrinter(hPrinter);
                }
                ClosePrinter(hPrinter);
            }
            // 如果没有成功,可能会给更多的信息GetLastError 
            if (bSuccess == false)
            {
                dwError = Marshal.GetLastWin32Error();
            }
            return bSuccess;
        }

        public static bool SendFileToPrinter(string szPrinterName, string szFileName)
        {
            // 打开文件.
            FileStream fs = new FileStream(szFileName, FileMode.Open);
            // 创建一个主题的文件.
            BinaryReader br = new BinaryReader(fs);
            // .
            Byte[] bytes = new Byte[fs.Length];
            bool bSuccess = false;
            // 非托管指针
            IntPtr pUnmanagedBytes = new IntPtr(0);
            int nLength;

            nLength = Convert.ToInt32(fs.Length);
            // 读取文件的内容放入数组中.
            bytes = br.ReadBytes(nLength);
            // 分配一些非托管内存对于那些字节
            pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);
            // 复制管理到非托管数组的字节数组
            Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);
            // 发送到打印机的非托管的字节
            bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);
            // 非托管内存分配
            Marshal.FreeCoTaskMem(pUnmanagedBytes);
            return bSuccess;
        }

        public static bool SendStringToPrinter(string szPrinterName, string szString)
        {
            IntPtr pBytes;
            Int32 dwCount;
            // 有多少字符在字符串
            dwCount = szString.Length;
            // 假设打印机期待ANSI的文本,然后将字符串ANSI文本。
            pBytes = Marshal.StringToCoTaskMemAnsi(szString);
            // 转换后的字符串发送到打印机的ANSI
            SendBytesToPrinter(szPrinterName, pBytes, dwCount);
            Marshal.FreeCoTaskMem(pBytes);
            return true;
        }
    }
}