最近需要做一个打印的功能，于是在网上找到了这么一个方法。

　　[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;    }    public class PrintCode    {        [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);        /// 
        /// 该方法把非托管内存中的字节数组发送到打印机的打印队列        /// 
        /// 打印机名称        /// 非托管内存指针        /// 字节数        /// 
     
      成功返回true，失败时为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;            di.pDocName = "My C#.NET RAW Document";            di.pDataType = "RAW";            try            {                // 打开打印机                if (OpenPrinter(szPrinterName.Normalize(), out hPrinter, IntPtr.Zero))                {                    // 启动文档打印                    if (StartDocPrinter(hPrinter, 1, di))                    {                        // 开始打印                        if (StartPagePrinter(hPrinter))                        {                            // 向打印机输出字节                              bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);                            EndPagePrinter(hPrinter);                        }                        EndDocPrinter(hPrinter);                    }                    ClosePrinter(hPrinter);                }                if (bSuccess == false)                {                    dwError = Marshal.GetLastWin32Error();                }            }            catch (Win32Exception ex)            {                WriteLog(ex.Message);                bSuccess = false;            }            return bSuccess;        }        /// 
        /// 发送文件到打印机方法        /// 
        /// 打印机名称        /// 打印文件的路径        /// 
             public static bool SendFileToPrinter(string szPrinterName, string szFileName)        {            bool bSuccess = false;            try            {                // 打开文件                  FileStream fs = new FileStream(szFileName, FileMode.Open);                // 将文件内容读作二进制                BinaryReader br = new BinaryReader(fs);                // 定义字节数组                Byte[] bytes = new Byte[fs.Length];                // 非托管指针                  IntPtr pUnmanagedBytes = new IntPtr(0);                int nLength;                nLength = Convert.ToInt32(fs.Length);                // 读取文件内容到字节数组                bytes = br.ReadBytes(nLength);                // 为这些字节分配一些非托管内存                pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);                // 将托管字节数组复制到非托管内存指针                Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);                // 将非托管字节发送到打印机                bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);                // 释放先前分配的非托管内存                Marshal.FreeCoTaskMem(pUnmanagedBytes);                fs.Close();                fs.Dispose();            }            catch (Win32Exception ex)            {                WriteLog(ex.Message);                bSuccess = false;            }            return bSuccess;        }        /// 
        /// 将字符串发送到打印机方法        /// 
        /// 打印机名称        /// 打印的字符串        /// 
             public static bool SendStringToPrinter(string szPrinterName, string szString)        {            bool flag = false;            try            {                IntPtr pBytes;                Int32 dwCount;                // 获取字符串长度                  dwCount = szString.Length;                // 将字符串复制到非托管 COM 任务分配的内存非托管内存块，并转换为 ANSI 文本                pBytes = Marshal.StringToCoTaskMemAnsi(szString);                // 将已转换的 ANSI 字符串发送到打印机                flag = SendBytesToPrinter(szPrinterName, pBytes, dwCount);                // 释放先前分配的非托管内存                Marshal.FreeCoTaskMem(pBytes);            }            catch (Win32Exception ex)            {                WriteLog(ex.Message);                flag = false;            }            return flag;        }        /// 
        /// 写入日志方法        /// 
        /// 记录信息        public static void WriteLog(string msg)        {            string str = string.Empty;            string path = AppDomain.CurrentDomain.BaseDirectory + "log\\" + DateTime.Now.ToString("yyyy-MM-dd") + ".txt";            FileStream filestream = new FileStream(path, FileMode.OpenOrCreate);            str += "************" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + "************\r\n";            str += msg;            str += "************" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + "************\r\n";            FileStream fs = new FileStream(path, FileMode.Append);            StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.Default);            sw.WriteLine(str);            sw.Flush();            sw.Close();            sw.Dispose();            fs.Close();            fs.Dispose();        }    }

以上就是全部代码了，调用就很简单了，方法如下：

private void Print_Click(object sender, EventArgs e)        {            //打印文件的路径，该方法获取到的文件路径在应用程序 bin\Debug\ 目录下，所以 ../../ 向上两级目录            string fileName = AppDomain.CurrentDomain.BaseDirectory + @"../../File/demo.txt";            if (PrintCode.SendFileToPrinter("PrinterName", fileName))            {                MessageBox.Show("文件已成功发送至打印队列！","提示信息");            }        }