Question

大家好，我已经坚持了一段时间了，我真的很想知道它是如何工作的，以及我没有得到什么。我有一个Apex3，我能够毫无问题地跟随the documentation的大部分内容，但是当谈到图像时，事情变得非常奇怪（缺乏示例+如何做到这一点缺乏一致性）。

首先，我尝试尝试使用JPEG和0质量传递Bitmap byte []数组压缩的天真方法，因为我不介意，使用命令

ESC V n1 n2数据

这样做不好。

然后我发现有一个用于apex3的安卓库，它接受一个位图并用来打印它但是它不起作用只是打印这样奇怪的符号：

enter image description here

我尝试使用JD gui对jar源进行解码，他们似乎使用位图字节做了一些工作，这是他们的代码（一些建议代码，如addToDoc（m_Document，ESC +“B”）;只需将代码放入一个ByteArrayOutputStream数据），（反编译source from here）：

public void writeImage(Bitmap imageObject, int printHeadWidth)
    throws IllegalArgumentException
  {
    if (imageObject == null) {
      throw new IllegalArgumentException("Parameter 'imageObject' was null.");
    }
    if (printHeadWidth < 1) {
      throw new IllegalArgumentException("Parameter 'printHeadWidth' must be greater than 0.");
    }
    int height = imageObject.getHeight();
    int width = imageObject.getWidth();


    byte blanklineCount = 0;
    byte[] dataline = new byte[printHeadWidth + 7 >> 3];
    int[] imageData = new int[height * width];

    imageObject.getPixels(imageData, 0, width, 0, 0, width, height);


    addToDoc(m_Document, ESC + "B");
    for (int row = 0; row < height; row++)
    {
      boolean blankLine = true;
      for (int index = 0; index < width; index += 8)
      {
        byte currentByte = 0;
        int offset = row * width + index;
        if (index >= printHeadWidth) {
          break;
        }
        int value = index + 0 < width ? imageData[(offset + 0)] & 0xFFFFFF : 16777215;
        boolean set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
        currentByte = (byte)(currentByte | (set ? -128 : 0));

        value = index + 1 < width ? imageData[(offset + 1)] & 0xFFFFFF : 16777215;
        set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
        currentByte = (byte)(currentByte | (set ? 64 : 0));

        value = index + 2 < width ? imageData[(offset + 2)] & 0xFFFFFF : 16777215;
        set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
        currentByte = (byte)(currentByte | (set ? 32 : 0));

        value = index + 3 < width ? imageData[(offset + 3)] & 0xFFFFFF : 16777215;
        set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
        currentByte = (byte)(currentByte | (set ? 16 : 0));

        value = index + 4 < width ? imageData[(offset + 4)] & 0xFFFFFF : 16777215;
        set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
        currentByte = (byte)(currentByte | (set ? 8 : 0));

        value = index + 5 < width ? imageData[(offset + 5)] & 0xFFFFFF : 16777215;
        set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
        currentByte = (byte)(currentByte | (set ? 4 : 0));

        value = index + 6 < width ? imageData[(offset + 6)] & 0xFFFFFF : 16777215;
        set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
        currentByte = (byte)(currentByte | (set ? 2 : 0));

        value = index + 7 < width ? imageData[(offset + 7)] & 0xFFFFFF : 16777215;
        set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
        currentByte = (byte)(currentByte | (set ? 1 : 0));


        dataline[(index >> 3)] = currentByte;
        blankLine &= currentByte == 0;
      }
      if (!blankLine)
      {
        if (blanklineCount > 0)
        {
          addToDoc(m_Document, "A");
          addToDoc(m_Document, blanklineCount);
          blanklineCount = 0;
        }
        addToDoc(m_Document, compressGraphicLine(dataline));
      }
      else
      {
        blanklineCount = (byte)(blanklineCount + 1);
        if (blanklineCount == 255)
        {
          addToDoc(m_Document, "A");
          addToDoc(m_Document, blanklineCount);
          blanklineCount = 0;
        }
      }
    }
    if (blanklineCount > 0)
    {
      addToDoc(m_Document, "A");
      addToDoc(m_Document, blanklineCount);
      blanklineCount = 0;
    }
    addToDoc(m_Document, ESC + "E");
  }

  private byte[] compressGraphicLine(byte[] dataline)
  {
    byte count = 0;
    byte currentByte = 0;
    ByteArrayOutputStream rleString = new ByteArrayOutputStream(128);


    addToDoc(rleString, "G");
    for (int index = 0; index < dataline.length; index++) {
      if (count == 0)
      {
        currentByte = dataline[index];
        addToDoc(rleString, currentByte);
        count = (byte)(count + 1);
      }
      else if ((count < 255) && (currentByte == dataline[index]))
      {
        count = (byte)(count + 1);
      }
      else
      {
        addToDoc(rleString, count);
        count = 0;


        currentByte = dataline[index];
        addToDoc(rleString, currentByte);
        count = (byte)(count + 1);
      }
    }
    if (count > 0) {
      addToDoc(rleString, count);
    }
    if (rleString.size() > dataline.length + 1)
    {
      rleString.reset();
      addToDoc(rleString, "U");
      for (int item = 0; item < dataline.length; item++) {
        addToDoc(rleString, dataline[item]);
      }
    }
    return rleString.toByteArray();
  }

但我不明白为什么它不起作用

最后，我尝试使用 How can I print an image on a Bluetooth printer in Android? ，使用相同的算法作为指南，但仍打印随机奇怪的符号。

Answer 1

而不是浪费时间反编译一些apk，为什么不看看官方SDK呢？在制造商网页Downloads & Drivers上有一个指向Java SDK的链接，其中包含来源Sample.java。在源代码中创建BufferedImage所以我猜（我没有这样的打印机），这将为您提供问题的切入点。最有可能的是，他们在同一页面上提供了Android演示Printer Demo Source code for Android

的来源

修改确定。让我们总结一下：你有一个图像，想要打印它。在示例Sample.java中涵盖了这种情况

  BufferedImage newImage = new BufferedImage(1024, 512, BufferedImage.TYPE_4BYTE_ABGR);
  // some lines and rectangles are drawn in the image
  ...
  // the image is printed, following the SDK javadoc for DocumentLP.writeImage
  // "This will cause the image specified to be printed. Images will be expanded to occupy
  // the entire width of the printer, so the correct current width of the printer must be
  // specified. Images that are too wide will be cropped, and images that are too narrow 
  // will be padded on the right."
  testDoc.writeImage(newImage, m_PrinterWidth);

对我来说，你唯一需要做的事情是：

创建一个BufferedImage对象
将图像从文件中绘制到缓冲图像
调用DocumentLP对象的writeImage方法

编辑2 伪代码段

// taken from SDK javadoc
DocumentLP docLP;
docLP = new DocumentLP("$");

// own code
BufferedInputStream bis = new BufferedInputStream(--from your image--);
BufferedImage bufImage = ImageIO.read(bis);

// have a look into Sample.java for the expected value of m_PrinterWidth
testDoc.writeImage(bufImage, m_PrinterWidth);

适用于Android的

编辑3 代码段（取自datamax o´neil Android SDK提供的DO_AndroidSDKDemo_MainActivity.java

File file = new File(selectedPath);
byte[] readBuffer = new byte[(int)file.length()];
InputStream inputStream= new BufferedInputStream(new FileInputStream(file));
inputStream.read(readBuffer);
inputStream.close();
fileData = readBuffer;

Bitmap m_imageObject = BitmapFactory.decodeByteArray(fileData, 0, fileData.length);
documentLP.clear();
ocumentLP.writeImage(m_imageObject, m_printHeadWidth);

打印POS / ESC Apex3图像S.O.S

1 个答案: