将PNG图像打印到斑马网络打印机

Question

我试图找到一种将图像打印到斑马并且遇到很多麻烦的方法.

根据文件:

第一种编码称为B64,使用MIME Base64方案对数据进行编码.Base64用于对电子邮件缓存进行编码...
Base64对该字节进行6位编码,对未封闭数据的扩展为33%.
第二种编码称为Z64,首先使用LZ77算法压缩数据以减小其大小.(该算法由PKZIP使用,并且与PNG图形格式是一体的.)
然后使用如上所述的MIME Base64方案对压缩数据进行编码.
将根据Base64编码的数据计算CRC.

但它没有更多的信息.

基本上我正在尝试编码

private byte[] GetItemFromPath(string filepath)
{   
    using (MemoryStream ms = new MemoryStream())
    {
        using (Image img = Image.FromFile(filepath))
        {
            img.Save(ms, ImageFormat.Png);
            return ms.ToArray();
        }
    }
}

然后尝试使用以下内容进行打印:

var initialArray = GetItemFromPath("C:\\RED.png");
string converted = Convert.ToBase64String(b);

PrintThis(string.Format(@"~DYRED.PNG,P,P,{1},0,:B64:
{0}
^XA
^F0200,200^XGRED.PNG,1,1^FS
^XZ", converted .ToString(), initialArray.Length));

根据它的声音,B64或Z64都被接受.

我尝试了一些变体,以及几种生成CRC和计算'大小'的方法.但似乎没有工作,并且图形下载到打印机总是被中止.

有没有人设法完成这样的事情？或者知道我哪里出错了？

Answer 1

我得到这个答案的所有功劳都来自LabView论坛用户Raydur.他发布了一个可以在LabView中打开的LabView解决方案,用于发送图像.我个人没有用我的打印机运行它,我只是用它来找出正确的图像代码,所以我可以在我的代码中复制它.我遗漏的重要事情是填充我的十六进制代码.例如:1A很好,但是如果你只有A,你需要在它前面填0以发送0A.您发送的ZPL中文件的大小也是字节数组的原始大小,而不是数据的最终字符串表示形式.

我已经搜索过很多很多很多论坛和Stackoverflow帖子试图解决这个问题,因为看起来这么简单.我已尝试在其他地方发布的每一个解决方案,但我真的只想打印一个.PNG,因为我的打印机手册(Mobile QLN320)支持它内置.它说要么用Base64或Hexadecimal发送,我试过两者都无济于事.对于任何想要做Base64的人,我在一本较旧的手册中发现你需要为你发送的每个数据包手动计算CRC码,所以我选择了更简单的十六进制路由.所以这是我开始工作的代码!

        string ipAddress = "192.168.1.30";
        int port = 6101;

        string zplImageData = string.Empty;
        //Make sure no transparency exists. I had some trouble with this. This PNG has a white background
        string filePath = @"C:\Users\Path\To\Logo.png";
        byte[] binaryData = System.IO.File.ReadAllBytes(filePath);
        foreach (Byte b in binaryData)
        {
            string hexRep = String.Format("{0:X}", b);
            if (hexRep.Length == 1)
                hexRep = "0" + hexRep;
            zplImageData += hexRep;
          }
          string zplToSend = "^XA" + "^MNN" + "^LL500" + "~DYE:LOGO,P,P," + binaryData.Length + ",," + zplImageData+"^XZ";
          string printImage = "^XA^FO115,50^IME:LOGO.PNG^FS^XZ";

        try
        {
            // Open connection
            System.Net.Sockets.TcpClient client = new System.Net.Sockets.TcpClient();
            client.Connect(ipAddress, port);

            // Write ZPL String to connection
            System.IO.StreamWriter writer = new System.IO.StreamWriter(client.GetStream(),Encoding.UTF8);
            writer.Write(zplToSend);
            writer.Flush();
            writer.Write(printImage);
            writer.Flush();
            // Close Connection
            writer.Close();
            client.Close();
        }
        catch (Exception ex)
        {
            // Catch Exception
        }

Answer 2

该ZPL II编程指南文档的~DG命令和GRF格式(第124页)下载图像.第二卷添加了有关可选压缩格式的详细信息(第52页).

首先,您必须将图像转换为1bpp双层图像,然后将其转换为十六进制编码的字符串.您可以进一步压缩图像以减少传输时间.然后,您可以使用^ID命令打印图像.

虽然~DY命令中对PNG图像有固有的支持,但它的文档记录很少,似乎不适用于某些型号的打印机.ZB64格式基本上没有记录,尝试从Zebra支持获取更多信息也没有结果.如果你的心脏设置在ZB64上,你可以使用基于Java的Zebralink SDK(查看ImagePrintDemo.java和com.zebra.sdk.printer.internal.GraphicsConversionUtilZpl.sendImageToStream).

获得命令数据后,如果打印机有打印服务器,则可以通过TCP/IP发送,也可以通过将RAW格式写入打印机来发送.

下面的代码将5 kB PNG打印为13 kB压缩GRF(60 kB未压缩):

class Program
{
    static unsafe void Main(string[] args)
    {
        var baseStream = new MemoryStream();
        var tw = new StreamWriter(baseStream, Encoding.UTF8);

        using (var bmpSrc = new Bitmap(Image.FromFile(@"label.png")))
        {
            tw.WriteLine(ZplImage.GetGrfStoreCommand("R:LBLRA2.GRF", bmpSrc));
        }
        tw.WriteLine(ZplImage.GetGrfPrintCommand("R:LBLRA2.GRF"));
        tw.WriteLine(ZplImage.GetGrfDeleteCommand("R:LBLRA2.GRF"));

        tw.Flush();
        baseStream.Position = 0;

        var gdipj = new GdiPrintJob("ZEBRA S4M-200dpi ZPL", GdiPrintJobDataType.Raw, "Raw print", null);
        gdipj.WritePage(baseStream);
        gdipj.CompleteJob();
    }
}

class ZplImage
{
    public static string GetGrfStoreCommand(string filename, Bitmap bmpSource)
    {
        if (bmpSource == null)
        {
            throw new ArgumentNullException("bmpSource");
        }
        validateFilename(filename);

        var dim = new Rectangle(Point.Empty, bmpSource.Size);
        var stride = ((dim.Width + 7) / 8);
        var bytes = stride * dim.Height;

        using (var bmpCompressed = bmpSource.Clone(dim, PixelFormat.Format1bppIndexed))
        {
            var result = new StringBuilder();

            result.AppendFormat("^XA~DG{2},{0},{1},", stride * dim.Height, stride, filename);
            byte[][] imageData = GetImageData(dim, stride, bmpCompressed);

            byte[] previousRow = null;
            foreach (var row in imageData)
            {
                appendLine(row, previousRow, result);
                previousRow = row;
            }
            result.Append(@"^FS^XZ");

            return result.ToString();
        }
    }

    public static string GetGrfDeleteCommand(string filename)
    {
        validateFilename(filename);

        return string.Format("^XA^ID{0}^FS^XZ", filename);
    }

    public static string GetGrfPrintCommand(string filename)
    {
        validateFilename(filename);

        return string.Format("^XA^FO0,0^XG{0},1,1^FS^XZ", filename);
    }

    static Regex regexFilename = new Regex("^[REBA]:[A-Z0-9]{1,8}\\.GRF$");

    private static void validateFilename(string filename)
    {
        if (!regexFilename.IsMatch(filename))
        {
            throw new ArgumentException("Filename must be in the format "
                + "R:XXXXXXXX.GRF.  Drives are R, E, B, A.  Filename can "
                + "be alphanumeric between 1 and 8 characters.", "filename");
        }
    }

    unsafe private static byte[][] GetImageData(Rectangle dim, int stride, Bitmap bmpCompressed)
    {
        byte[][] imageData;
        var data = bmpCompressed.LockBits(dim, ImageLockMode.ReadOnly, PixelFormat.Format1bppIndexed);
        try
        {
            byte* pixelData = (byte*)data.Scan0.ToPointer();
            byte rightMask = (byte)(0xff << (data.Stride * 8 - dim.Width));
            imageData = new byte[dim.Height][];

            for (int row = 0; row < dim.Height; row++)
            {
                byte* rowStart = pixelData + row * data.Stride;
                imageData[row] = new byte[stride];

                for (int col = 0; col < stride; col++)
                {
                    byte f = (byte)(0xff ^ rowStart[col]);
                    f = (col == stride - 1) ? (byte)(f & rightMask) : f;
                    imageData[row][col] = f;
                }
            }
        }
        finally
        {
            bmpCompressed.UnlockBits(data);
        }
        return imageData;
    }

    private static void appendLine(byte[] row, byte[] previousRow, StringBuilder baseStream)
    {
        if (row.All(r => r == 0))
        {
            baseStream.Append(",");
            return;
        }

        if (row.All(r => r == 0xff))
        {
            baseStream.Append("!");
            return;
        }

        if (previousRow != null && MatchByteArray(row, previousRow))
        {
            baseStream.Append(":");
            return;
        }

        byte[] nibbles = new byte[row.Length * 2];
        for (int i = 0; i < row.Length; i++)
        {
            nibbles[i * 2] = (byte)(row[i] >> 4);
            nibbles[i * 2 + 1] = (byte)(row[i] & 0x0f);
        }

        for (int i = 0; i < nibbles.Length; i++)
        {
            byte cPixel = nibbles[i];

            int repeatCount = 0;
            for (int j = i; j < nibbles.Length && repeatCount <= 400; j++)
            {
                if (cPixel == nibbles[j])
                {
                    repeatCount++;
                }
                else
                {
                    break;
                }
            }

            if (repeatCount > 2)
            {
                if (repeatCount == nibbles.Length - i
                    && (cPixel == 0 || cPixel == 0xf))
                {
                    if (cPixel == 0)
                    {
                        if (i % 2 == 1)
                        {
                            baseStream.Append("0");
                        }
                        baseStream.Append(",");
                        return;
                    }
                    else if (cPixel == 0xf)
                    {
                        if (i % 2 == 1)
                        {
                            baseStream.Append("F");
                        }
                        baseStream.Append("!");
                        return;
                    }
                }
                else
                {
                    baseStream.Append(getRepeatCode(repeatCount));
                    i += repeatCount - 1;
                }
            }
            baseStream.Append(cPixel.ToString("X"));
        }
    }

    private static string getRepeatCode(int repeatCount)
    {
        if (repeatCount > 419)
            throw new ArgumentOutOfRangeException();

        int high = repeatCount / 20;
        int low = repeatCount % 20;

        const string lowString = " GHIJKLMNOPQRSTUVWXY";
        const string highString = " ghijklmnopqrstuvwxyz";

        string repeatStr = "";
        if (high > 0)
        {
            repeatStr += highString[high];
        }
        if (low > 0)
        {
            repeatStr += lowString[low];
        }

        return repeatStr;
    }

    private static bool MatchByteArray(byte[] row, byte[] previousRow)
    {
        for (int i = 0; i < row.Length; i++)
        {
            if (row[i] != previousRow[i])
            {
                return false;
            }
        }

        return true;
    }
}

internal static class NativeMethods
{
    #region winspool.drv

    #region P/Invokes

    [DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern bool OpenPrinter(string szPrinter, out IntPtr hPrinter, IntPtr pd);

    [DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern bool ClosePrinter(IntPtr hPrinter);

    [DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern UInt32 StartDocPrinter(IntPtr hPrinter, Int32 level, IntPtr di);

    [DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern bool EndDocPrinter(IntPtr hPrinter);

    [DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern bool StartPagePrinter(IntPtr hPrinter);

    [DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern bool EndPagePrinter(IntPtr hPrinter);

    [DllImport("winspool.Drv", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern bool WritePrinter(
        // 0
        IntPtr hPrinter,
        [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 2)] byte[] pBytes,
        // 2
        UInt32 dwCount,
        out UInt32 dwWritten);

    #endregion

    #region Structs

    [StructLayout(LayoutKind.Sequential)]
    internal struct DOC_INFO_1
    {
        [MarshalAs(UnmanagedType.LPWStr)]
        public string DocName;
        [MarshalAs(UnmanagedType.LPWStr)]
        public string OutputFile;
        [MarshalAs(UnmanagedType.LPWStr)]
        public string Datatype;
    }

    #endregion

    #endregion
}

/// <summary>
/// Represents a print job in a spooler queue
/// </summary>
public class GdiPrintJob
{
    IntPtr PrinterHandle;
    IntPtr DocHandle;

    /// <summary>
    /// The ID assigned by the print spooler to identify the job
    /// </summary>
    public UInt32 PrintJobID { get; private set; }

    /// <summary>
    /// Create a print job with a enumerated datatype
    /// </summary>
    /// <param name="PrinterName"></param>
    /// <param name="dataType"></param>
    /// <param name="jobName"></param>
    /// <param name="outputFileName"></param>
    public GdiPrintJob(string PrinterName, GdiPrintJobDataType dataType, string jobName, string outputFileName)
        : this(PrinterName, translateType(dataType), jobName, outputFileName)
    {
    }

    /// <summary>
    /// Create a print job with a string datatype
    /// </summary>
    /// <param name="PrinterName"></param>
    /// <param name="dataType"></param>
    /// <param name="jobName"></param>
    /// <param name="outputFileName"></param>
    public GdiPrintJob(string PrinterName, string dataType, string jobName, string outputFileName)
    {
        if (string.IsNullOrWhiteSpace(PrinterName))
            throw new ArgumentNullException("PrinterName");
        if (string.IsNullOrWhiteSpace(dataType))
            throw new ArgumentNullException("PrinterName");

        IntPtr hPrinter;
        if (!NativeMethods.OpenPrinter(PrinterName, out hPrinter, IntPtr.Zero))
            throw new Win32Exception();
        this.PrinterHandle = hPrinter;

        NativeMethods.DOC_INFO_1 docInfo = new NativeMethods.DOC_INFO_1()
        {
            DocName = jobName,
            Datatype = dataType,
            OutputFile = outputFileName
        };
        IntPtr pDocInfo = Marshal.AllocHGlobal(Marshal.SizeOf(docInfo));
        RuntimeHelpers.PrepareConstrainedRegions();
        try
        {
            Marshal.StructureToPtr(docInfo, pDocInfo, false);
            UInt32 docid = NativeMethods.StartDocPrinter(hPrinter, 1, pDocInfo);
            if (docid == 0)
                throw new Win32Exception();
            this.PrintJobID = docid;
        }
        finally
        {
            Marshal.FreeHGlobal(pDocInfo);
        }
    }

    /// <summary>
    /// Write the data of a single page or a precomposed PCL document
    /// </summary>
    /// <param name="data"></param>
    public void WritePage(Stream data)
    {
        if (data == null)
            throw new ArgumentNullException("data");
        if (!data.CanRead && !data.CanWrite)
            throw new ObjectDisposedException("data");
        if (!data.CanRead)
            throw new NotSupportedException("stream is not readable");

        if (!NativeMethods.StartPagePrinter(this.PrinterHandle))
            throw new Win32Exception();

        byte[] buffer = new byte[0x14000]; /* 80k is Stream.CopyTo default */
        uint read = 1;
        while ((read = (uint)data.Read(buffer, 0, buffer.Length)) != 0)
        {
            UInt32 written;
            if (!NativeMethods.WritePrinter(this.PrinterHandle, buffer, read, out written))
                throw new Win32Exception();

            if (written != read)
                throw new InvalidOperationException("Error while writing to stream");
        }

        if (!NativeMethods.EndPagePrinter(this.PrinterHandle))
            throw new Win32Exception();
    }

    /// <summary>
    /// Complete the current job
    /// </summary>
    public void CompleteJob()
    {
        if (!NativeMethods.EndDocPrinter(this.PrinterHandle))
            throw new Win32Exception();
    }

    #region datatypes
    private readonly static string[] dataTypes = new string[] 
    { 
        // 0
        null, 
        "RAW", 
        // 2
        "RAW [FF appended]",
        "RAW [FF auto]",
        // 4
        "NT EMF 1.003", 
        "NT EMF 1.006",
        // 6
        "NT EMF 1.007", 
        "NT EMF 1.008", 
        // 8
        "TEXT", 
        "XPS_PASS", 
        // 10
        "XPS2GDI" 
    };

    private static string translateType(GdiPrintJobDataType type)
    {
        return dataTypes[(int)type];
    }
    #endregion
}

public enum GdiPrintJobDataType
{
    Unknown = 0,
    Raw = 1,
    RawAppendFF = 2,
    RawAuto = 3,
    NtEmf1003 = 4,
    NtEmf1006 = 5,
    NtEmf1007 = 6,
    NtEmf1008 = 7,
    Text = 8,
    XpsPass = 9,
    Xps2Gdi = 10
}

Answer 3

查看 ZPL 手册后，您需要计算图像的循环冗余校验(CRC)。下面是一些计算 CRC 的 C 代码（来源）：

// Update the CRC for transmitted and received data using
// the CCITT 16bit algorithm (X^16 + X^12 + X^5 + 1).

unsigned char ser_data;
static unsigned int crc;

crc  = (unsigned char)(crc >> 8) | (crc << 8);
crc ^= ser_data;
crc ^= (unsigned char)(crc & 0xff) >> 4;
crc ^= (crc << 8) << 4;
crc ^= ((crc & 0xff) << 4) << 1;

您还可以参考 CRC 的维基百科页面，因为它还包含其他代码示例。

https://en.wikipedia.org/wiki/Cyclic_redundancy_check

您发送的其他所有内容看起来都不错。我会考虑使用 Zebra SDK 之一。我知道 Android 设备会将图像发送到打印机并为您保存。