C#直接发送打印机命令到打印机及ZPL常用打印命令

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

namespace BarCodeLibrary
{
    public class ZebraGesigner
    {
        [StructLayout(LayoutKind.Sequential)]
        private struct OVERLAPPED
        {
            int Internal;
            int InternalHigh;
            int Offset;
            int OffSetHigh;
            int hEvent;
        }
        [DllImport("kernel32.dll")]
        private static extern int CreateFile(string lpFileName, uint dwDesiredAccess, int dwShareMode, int lpSecurityAttributes, int dwCreationDisposition, int dwFlagsAndAttributes, int hTemplateFile);
        [DllImport("kernel32.dll")]
        private static extern bool WriteFile(int hFile, byte[] lpBuffer, int nNumberOfBytesToWriter, out int lpNumberOfBytesWriten, out OVERLAPPED lpOverLapped);
        [DllImport("kernel32.dll")]
        private static extern bool CloseHandle(int hObject);
        [DllImport("fnthex32.dll")]
        public static extern int GETFONTHEX(string barcodeText,string fontName,int orient,int height,int width,int isBold,int isItalic,StringBuilder returnBarcodeCMD);
        private int iHandle;
        //打开LPT 端口
        public bool Open()
        {
            iHandle = CreateFile("lpt1", 0x40000000, 0, 0, 3, 0, 0);
            if (iHandle != -1)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        //打印函数，参数为打印机的命令或者其他文本！
        public bool Write(string MyString)
        {
            if (iHandle != -1)
            {
                int i;
                OVERLAPPED x;
                byte[] mybyte = System.Text.Encoding.Default.GetBytes(MyString);
                return WriteFile(iHandle, mybyte, mybyte.Length, out i, out x);
            }
            else
            {
                throw new Exception("端口未打开~！");
            }
        }
　　　　 //关闭打印端口
        public bool Close()
        {
            return CloseHandle(iHandle);
        }
    }
}
vate void button1_Click(object sender, EventArgs e)  
 {  
     ZebraGesigner zb = new ZebraGesigner();  
     string mycommanglines = System.IO.File.ReadAllText("print.txt");//print.txt里写了条码机的命令  
     zb.Open();  
     zb.Write(mycommanglines);  
     zb.Close();  
}
/*
    ^XA                   ^XA指令块的开始     
    ^MD30                 ^MD是设置色带颜色的深度,取值范围从-30到30,上面的示意指令将颜色调到了最深.          
    ^LH60,10              ^LH是设置条码纸的边距的,这个东西在实际操作上来回试几次即可.
    ^FO20,10              ^FO是设置条码左上角的位置的,这个对程序员应该很容易理解. 0,0代表完全不留边距.
    ^ACN,18,10            ^ACN是设置字体的.因为在条码下方会显示该条码的内容,所以要设一下字体.这个跟条码无关.
    ^BY1.4,3,50           ^BY是设置条码样式的,1.4是条码的缩放级别,3是条码中粗细柱的比例,50是条码高度.
    ^BCN,,Y,N              ^BC是打印code128的指令,具体参数详见ZPL的说明书(百度云盘)
    ^FD01008D004Q-0^FS    ^FD设置要打印的内容, ^FS表示换行.
    ^XZ                   ^XZ指令块的开始    
*/
StringBuilder builder = new StringBuilder();
builder.AppendLine("^XA");
builder.AppendLine("^MD30");
builder.AppendLine("^LH60,10");
builder.AppendLine("^FO20,10");
builder.AppendLine("^ACN,18,10");
builder.AppendLine("^BY1.4,3,50");
builder.AppendLine("^BCN,,Y,N");
builder.AppendLine("^FD01008D004Q-0^FS");
builder.AppendLine("^XZ");
在实践中, 常常会需要一次横打两张, 其实可以把一排的两张想像成一张, 连续执行两个打印命令, 把第二个FO的横坐标设置得大一些就行了. 
例如:
^XA 
^FO20,10
^FD001^FS 
^FO60,10
^FD002^FS 
^XZ
第一对FO/FD命令打印左侧, 第二对FO/FD命令打印右侧. 
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Drawing;
using System.Drawing.Printing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace ZPLPrinter
{
    class RawPrinterHelper
    {
        // 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, 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()
        // When the function is given a printer name and an unmanaged array
        // of bytes, the function sends those bytes to the print queue.
        // Returns true on success, false on failure.
        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; // Assume failure unless you specifically succeed.

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

            // Open the printer.
            if (OpenPrinter(szPrinterName.Normalize(), out hPrinter, IntPtr.Zero))
            {
                // Start a document.
                if (StartDocPrinter(hPrinter, 1, di))
                {
                    // Start a page.
                    if (StartPagePrinter(hPrinter))
                    {
                        // Write your bytes.
                        bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
                        EndPagePrinter(hPrinter);
                    }
                    EndDocPrinter(hPrinter);
                }
                ClosePrinter(hPrinter);
            }
            // If you did not succeed, GetLastError may give more information
            // about why not.
            if (bSuccess == false)
            {
                dwError = Marshal.GetLastWin32Error();
            }
            return bSuccess;
        }

        public static bool SendFileToPrinter(string szPrinterName, string szFileName)
        {
            // Open the file.
            FileStream fs = new FileStream(szFileName, FileMode.Open);
            // Create a BinaryReader on the file.
            BinaryReader br = new BinaryReader(fs);
            // Dim an array of bytes big enough to hold the file's contents.
            Byte[] bytes = new Byte[fs.Length];
            bool bSuccess = false;
            // Your unmanaged pointer.
            IntPtr pUnmanagedBytes = new IntPtr(0);
            int nLength;

            nLength = Convert.ToInt32(fs.Length);
            // Read the contents of the file into the array.
            bytes = br.ReadBytes(nLength);
            // Allocate some unmanaged memory for those bytes.
            pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);
            // Copy the managed byte array into the unmanaged array.
            Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);
            // Send the unmanaged bytes to the printer.
            bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);
            // Free the unmanaged memory that you allocated earlier.
            Marshal.FreeCoTaskMem(pUnmanagedBytes);
            return bSuccess;
        }

        public static bool SendStringToPrinter(string szPrinterName, string szString)
        {
            IntPtr pBytes;
            Int32 dwCount;
            // How many characters are in the string?
            dwCount = szString.Length;
            // Assume that the printer is expecting ANSI text, and then convert
            // the string to ANSI text.
            pBytes = Marshal.StringToCoTaskMemAnsi(szString);
            // Send the converted ANSI string to the printer.
            SendBytesToPrinter(szPrinterName, pBytes, dwCount);
            Marshal.FreeCoTaskMem(pBytes);
            return true;
        }
    }
}
    public string Print(string stuNo, string liuBookNo, string suoBookNum, string stuName)
    {
        if (string.IsNullOrEmpty(liuBookNo) || string.IsNullOrEmpty(suoBookNum))
        {
            return "参数错误,打印失败!";
        }
        StringBuilder tiaomaStr = new StringBuilder();
        tiaomaStr.AppendLine();
        tiaomaStr.AppendLine("N");
        tiaomaStr.AppendLine("B0,10,0,1,2,3,100,B,$" + suoBookNum + "$");
        tiaomaStr.AppendLine("A2050,10,5,9,1,1,N,$" + liuBookNo + "$");
        tiaomaStr.AppendLine("A0,160,0,8,1,1,N,$未知$");
        tiaomaStr.AppendLine("A0,210,0,8,1,1,N,$捐书人:" + stuName + "$");
        tiaomaStr.AppendLine("D15");
        tiaomaStr.AppendLine("P1");
        FileStream fs = null;
        try
        {
            string path = Server.MapPath("~/BooksManagement\File\tiaoma.txt");
            fs = new FileStream(path, FileMode.Create, FileAccess.Write);
            StreamWriter sw = new StreamWriter(fs, Encoding.Default);//ANSI编码格式
            if (File.Exists(path))
            {
                sw.Write(tiaomaStr.ToString().Replace('$', '"'));
                tiaomaStr.Clear();
                sw.Flush();
                sw.Close();
                if (RunCmd("COPY " + path + " LPT1"))
                    return string.Empty;
                else
                    return "参数错误,打印失败!";
            }
        }
        catch
        {
        }
        finally
        {
            fs.Close();
        }
        return "参数错误,打印失败!";
    }

    private bool RunCmd(string command)
    {
        //实例一个Process类，启动一个独立进程
        Process p = new Process();
        //Process类有一个StartInfo属性，這個是ProcessStartInfo类，包括了一些属性和方法，下面我們用到了他的几个属性：
        p.StartInfo.FileName = "cmd.exe";//设定程序名
        p.StartInfo.Arguments = "/c " + command;//设定程式执行参数
        p.StartInfo.UseShellExecute = false;//关闭Shell的使用
        p.StartInfo.RedirectStandardInput = true;//重定向标准输入
        p.StartInfo.RedirectStandardOutput = true;//重定向标准输出
        p.StartInfo.RedirectStandardError = true;//重定向错误输出
        p.StartInfo.CreateNoWindow = true;//设置不显示窗口
        //p.StandardInput.WriteLine(command);//也可以用这种方式输入要执行的命令
        //p.StandardInput.WriteLine("exit");//不过要记得加上Exit要不然下一行程式执行的時候会当机
        try
        {
            p.Start();//开始进程
            return true;
        }
        catch
        {
        }
        finally
        {
            if (p != null)
                p.Close();
        }
        return false;
    }
        /*
             中文或其它复杂设计成图片，然后用ZPL命令发送给条码打印机打印             
            //定义字体  
            Font drawFont = new Font("Arial", 10, FontStyle.Bold, GraphicsUnit.Millimeter);
            //生成图片
            Bitmap img = CreateImage("出厂日期：" + DateTime.Now, drawFont);
            var imgCode = ConvertImageToCode(img);
            var t = ((img.Size.Width / 8 + ((img.Size.Width % 8 == 0) ? 0 : 1)) * img.Size.Height).ToString(); //图形中的总字节数
            var w = (img.Size.Width / 8 + ((img.Size.Width % 8 == 0) ? 0 : 1)).ToString(); //每行的字节数
            string zpl = string.Format("~DGR:imgName.GRF,{0},{1},{2}", t, w, imgCode); //发送给打印机
        */

        /// <summary>
        /// 生成Bitmap
        /// </summary>
        /// <param name="data">字符串</param>
        /// <param name="f">文本格式</param>
        /// <returns></returns>
        protected Bitmap CreateImage(string data, Font f)
        {
            if (string.IsNullOrEmpty(data))
                return null;
            var txt = new TextBox();
            txt.Text = data;
            txt.Font = f;
            //txt.PreferredSize.Height只能取到一行的高度(连边距) 
            //所以需要乘以行数, 但是必须先减掉边距, 乘了以后,再把边距加上. 
            //5是目测的边距 
            var image = new Bitmap(txt.PreferredSize.Width, (txt.PreferredSize.Height - 5) * txt.Lines.Length + 5);
            var g = Graphics.FromImage(image);
            var b = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Black, Color.Black, 1.2f, true);
            g.Clear(System.Drawing.Color.White);
            g.DrawString(data, f, b, 1, 1);
            return image;
        }

        /// <summary>
        /// 序列化图片
        /// </summary>
        /// <param name="img">Bitmap</param>
        /// <returns></returns>
        protected string ConvertImageToCode(Bitmap img)
        {
            var sb = new StringBuilder();
            long clr = 0, n = 0;
            int b = 0;
            for (int i = 0; i < img.Size.Height; i++)
            {
                for (int j = 0; j < img.Size.Width; j++)
                {
                    b = b * 2;
                    clr = img.GetPixel(j, i).ToArgb();
                    string s = clr.ToString("X");

                    if (s.Substring(s.Length - 6, 6).CompareTo("BBBBBB") < 0)
                    {
                        b++;
                    }
                    n++;
                    if (j == (img.Size.Width - 1))
                    {
                        if (n < 8)
                        {
                            b = b * (2 ^ (8 - (int)n));

                            sb.Append(b.ToString("X").PadLeft(2, '0'));
                            b = 0;
                            n = 0;
                        }
                    }
                    if (n >= 8)
                    {
                        sb.Append(b.ToString("X").PadLeft(2, '0'));
                        b = 0;
                        n = 0;
                    }
                }
                sb.Append(System.Environment.NewLine);
            }
            return sb.ToString();
        }

　　

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

namespace BarCodeLibrary
{
    public class ZebraGesigner
    {
        [StructLayout(LayoutKind.Sequential)]
        private struct OVERLAPPED
        {
            int Internal;
            int InternalHigh;
            int Offset;
            int OffSetHigh;
            int hEvent;
        }
        [DllImport("kernel32.dll")]
        private static extern int CreateFile(string lpFileName, uint dwDesiredAccess, int dwShareMode, int lpSecurityAttributes, int dwCreationDisposition, int dwFlagsAndAttributes, int hTemplateFile);
        [DllImport("kernel32.dll")]
        private static extern bool WriteFile(int hFile, byte[] lpBuffer, int nNumberOfBytesToWriter, out int lpNumberOfBytesWriten, out OVERLAPPED lpOverLapped);
        [DllImport("kernel32.dll")]
        private static extern bool CloseHandle(int hObject);
        [DllImport("fnthex32.dll")]
        public static extern int GETFONTHEX(string barcodeText,string fontName,int orient,int height,int width,int isBold,int isItalic,StringBuilder returnBarcodeCMD);
        private int iHandle;
        //打开LPT 端口
        public bool Open()
        {
            iHandle = CreateFile("lpt1", 0x40000000, 0, 0, 3, 0, 0);
            if (iHandle != -1)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        //打印函数，参数为打印机的命令或者其他文本！
        public bool Write(string MyString)
        {
            if (iHandle != -1)
            {
                int i;
                OVERLAPPED x;
                byte[] mybyte = System.Text.Encoding.Default.GetBytes(MyString);
                return WriteFile(iHandle, mybyte, mybyte.Length, out i, out x);
            }
            else
            {
                throw new Exception("端口未打开~！");
            }
        }
　　　　 //关闭打印端口
        public bool Close()
        {
            return CloseHandle(iHandle);
        }
    }
}

vate void button1_Click(object sender, EventArgs e)  
 {  
     ZebraGesigner zb = new ZebraGesigner();  
     string mycommanglines = System.IO.File.ReadAllText("print.txt");//print.txt里写了条码机的命令  
     zb.Open();  
     zb.Write(mycommanglines);  
     zb.Close();  
}

/*
    ^XA                   ^XA指令块的开始     
    ^MD30                 ^MD是设置色带颜色的深度,取值范围从-30到30,上面的示意指令将颜色调到了最深.          
    ^LH60,10              ^LH是设置条码纸的边距的,这个东西在实际操作上来回试几次即可.
    ^FO20,10              ^FO是设置条码左上角的位置的,这个对程序员应该很容易理解. 0,0代表完全不留边距.
    ^ACN,18,10            ^ACN是设置字体的.因为在条码下方会显示该条码的内容,所以要设一下字体.这个跟条码无关.
    ^BY1.4,3,50           ^BY是设置条码样式的,1.4是条码的缩放级别,3是条码中粗细柱的比例,50是条码高度.
    ^BCN,,Y,N              ^BC是打印code128的指令,具体参数详见ZPL的说明书(百度云盘)
    ^FD01008D004Q-0^FS    ^FD设置要打印的内容, ^FS表示换行.
    ^XZ                   ^XZ指令块的开始    
*/
StringBuilder builder = new StringBuilder();
builder.AppendLine("^XA");
builder.AppendLine("^MD30");
builder.AppendLine("^LH60,10");
builder.AppendLine("^FO20,10");
builder.AppendLine("^ACN,18,10");
builder.AppendLine("^BY1.4,3,50");
builder.AppendLine("^BCN,,Y,N");
builder.AppendLine("^FD01008D004Q-0^FS");
builder.AppendLine("^XZ");

在实践中, 常常会需要一次横打两张, 其实可以把一排的两张想像成一张, 连续执行两个打印命令, 把第二个FO的横坐标设置得大一些就行了. 
例如:
^XA 
^FO20,10
^FD001^FS 
^FO60,10
^FD002^FS 
^XZ
第一对FO/FD命令打印左侧, 第二对FO/FD命令打印右侧. 

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Drawing;
using System.Drawing.Printing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace ZPLPrinter
{
    class RawPrinterHelper
    {
        // 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, 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()
        // When the function is given a printer name and an unmanaged array
        // of bytes, the function sends those bytes to the print queue.
        // Returns true on success, false on failure.
        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; // Assume failure unless you specifically succeed.

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

            // Open the printer.
            if (OpenPrinter(szPrinterName.Normalize(), out hPrinter, IntPtr.Zero))
            {
                // Start a document.
                if (StartDocPrinter(hPrinter, 1, di))
                {
                    // Start a page.
                    if (StartPagePrinter(hPrinter))
                    {
                        // Write your bytes.
                        bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
                        EndPagePrinter(hPrinter);
                    }
                    EndDocPrinter(hPrinter);
                }
                ClosePrinter(hPrinter);
            }
            // If you did not succeed, GetLastError may give more information
            // about why not.
            if (bSuccess == false)
            {
                dwError = Marshal.GetLastWin32Error();
            }
            return bSuccess;
        }

        public static bool SendFileToPrinter(string szPrinterName, string szFileName)
        {
            // Open the file.
            FileStream fs = new FileStream(szFileName, FileMode.Open);
            // Create a BinaryReader on the file.
            BinaryReader br = new BinaryReader(fs);
            // Dim an array of bytes big enough to hold the file's contents.
            Byte[] bytes = new Byte[fs.Length];
            bool bSuccess = false;
            // Your unmanaged pointer.
            IntPtr pUnmanagedBytes = new IntPtr(0);
            int nLength;

            nLength = Convert.ToInt32(fs.Length);
            // Read the contents of the file into the array.
            bytes = br.ReadBytes(nLength);
            // Allocate some unmanaged memory for those bytes.
            pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);
            // Copy the managed byte array into the unmanaged array.
            Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);
            // Send the unmanaged bytes to the printer.
            bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);
            // Free the unmanaged memory that you allocated earlier.
            Marshal.FreeCoTaskMem(pUnmanagedBytes);
            return bSuccess;
        }

        public static bool SendStringToPrinter(string szPrinterName, string szString)
        {
            IntPtr pBytes;
            Int32 dwCount;
            // How many characters are in the string?
            dwCount = szString.Length;
            // Assume that the printer is expecting ANSI text, and then convert
            // the string to ANSI text.
            pBytes = Marshal.StringToCoTaskMemAnsi(szString);
            // Send the converted ANSI string to the printer.
            SendBytesToPrinter(szPrinterName, pBytes, dwCount);
            Marshal.FreeCoTaskMem(pBytes);
            return true;
        }
    }
}

    public string Print(string stuNo, string liuBookNo, string suoBookNum, string stuName)
    {
        if (string.IsNullOrEmpty(liuBookNo) || string.IsNullOrEmpty(suoBookNum))
        {
            return "参数错误,打印失败!";
        }
        StringBuilder tiaomaStr = new StringBuilder();
        tiaomaStr.AppendLine();
        tiaomaStr.AppendLine("N");
        tiaomaStr.AppendLine("B0,10,0,1,2,3,100,B,$" + suoBookNum + "$");
        tiaomaStr.AppendLine("A2050,10,5,9,1,1,N,$" + liuBookNo + "$");
        tiaomaStr.AppendLine("A0,160,0,8,1,1,N,$未知$");
        tiaomaStr.AppendLine("A0,210,0,8,1,1,N,$捐书人:" + stuName + "$");
        tiaomaStr.AppendLine("D15");
        tiaomaStr.AppendLine("P1");
        FileStream fs = null;
        try
        {
            string path = Server.MapPath("~/BooksManagement\File\tiaoma.txt");
            fs = new FileStream(path, FileMode.Create, FileAccess.Write);
            StreamWriter sw = new StreamWriter(fs, Encoding.Default);//ANSI编码格式
            if (File.Exists(path))
            {
                sw.Write(tiaomaStr.ToString().Replace('$', '"'));
                tiaomaStr.Clear();
                sw.Flush();
                sw.Close();
                if (RunCmd("COPY " + path + " LPT1"))
                    return string.Empty;
                else
                    return "参数错误,打印失败!";
            }
        }
        catch
        {
        }
        finally
        {
            fs.Close();
        }
        return "参数错误,打印失败!";
    }

    private bool RunCmd(string command)
    {
        //实例一个Process类，启动一个独立进程
        Process p = new Process();
        //Process类有一个StartInfo属性，這個是ProcessStartInfo类，包括了一些属性和方法，下面我們用到了他的几个属性：
        p.StartInfo.FileName = "cmd.exe";//设定程序名
        p.StartInfo.Arguments = "/c " + command;//设定程式执行参数
        p.StartInfo.UseShellExecute = false;//关闭Shell的使用
        p.StartInfo.RedirectStandardInput = true;//重定向标准输入
        p.StartInfo.RedirectStandardOutput = true;//重定向标准输出
        p.StartInfo.RedirectStandardError = true;//重定向错误输出
        p.StartInfo.CreateNoWindow = true;//设置不显示窗口
        //p.StandardInput.WriteLine(command);//也可以用这种方式输入要执行的命令
        //p.StandardInput.WriteLine("exit");//不过要记得加上Exit要不然下一行程式执行的時候会当机
        try
        {
            p.Start();//开始进程
            return true;
        }
        catch
        {
        }
        finally
        {
            if (p != null)
                p.Close();
        }
        return false;
    }

        /*
             中文或其它复杂设计成图片，然后用ZPL命令发送给条码打印机打印             
            //定义字体  
            Font drawFont = new Font("Arial", 10, FontStyle.Bold, GraphicsUnit.Millimeter);
            //生成图片
            Bitmap img = CreateImage("出厂日期：" + DateTime.Now, drawFont);
            var imgCode = ConvertImageToCode(img);
            var t = ((img.Size.Width / 8 + ((img.Size.Width % 8 == 0) ? 0 : 1)) * img.Size.Height).ToString(); //图形中的总字节数
            var w = (img.Size.Width / 8 + ((img.Size.Width % 8 == 0) ? 0 : 1)).ToString(); //每行的字节数
            string zpl = string.Format("~DGR:imgName.GRF,{0},{1},{2}", t, w, imgCode); //发送给打印机
        */

        /// <summary>
        /// 生成Bitmap
        /// </summary>
        /// <param name="data">字符串</param>
        /// <param name="f">文本格式</param>
        /// <returns></returns>
        protected Bitmap CreateImage(string data, Font f)
        {
            if (string.IsNullOrEmpty(data))
                return null;
            var txt = new TextBox();
            txt.Text = data;
            txt.Font = f;
            //txt.PreferredSize.Height只能取到一行的高度(连边距) 
            //所以需要乘以行数, 但是必须先减掉边距, 乘了以后,再把边距加上. 
            //5是目测的边距 
            var image = new Bitmap(txt.PreferredSize.Width, (txt.PreferredSize.Height - 5) * txt.Lines.Length + 5);
            var g = Graphics.FromImage(image);
            var b = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Black, Color.Black, 1.2f, true);
            g.Clear(System.Drawing.Color.White);
            g.DrawString(data, f, b, 1, 1);
            return image;
        }

        /// <summary>
        /// 序列化图片
        /// </summary>
        /// <param name="img">Bitmap</param>
        /// <returns></returns>
        protected string ConvertImageToCode(Bitmap img)
        {
            var sb = new StringBuilder();
            long clr = 0, n = 0;
            int b = 0;
            for (int i = 0; i < img.Size.Height; i++)
            {
                for (int j = 0; j < img.Size.Width; j++)
                {
                    b = b * 2;
                    clr = img.GetPixel(j, i).ToArgb();
                    string s = clr.ToString("X");

                    if (s.Substring(s.Length - 6, 6).CompareTo("BBBBBB") < 0)
                    {
                        b++;
                    }
                    n++;
                    if (j == (img.Size.Width - 1))
                    {
                        if (n < 8)
                        {
                            b = b * (2 ^ (8 - (int)n));

                            sb.Append(b.ToString("X").PadLeft(2, '0'));
                            b = 0;
                            n = 0;
                        }
                    }
                    if (n >= 8)
                    {
                        sb.Append(b.ToString("X").PadLeft(2, '0'));
                        b = 0;
                        n = 0;
                    }
                }
                sb.Append(System.Environment.NewLine);
            }
            return sb.ToString();
        }