如何在热敏打印机上正确对齐多个标签

Question

我尝试使用原生awt print API从java项目使用pos80热敏打印机在标签上打印二维码，结果如下。

请帮助我解决这个问题，并在标签中间一个接一个地打印二维码。

我使用javac 1.8.0_101，netbeans11.0，qrgen4来生成二维码。

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我用来从dir读取二维码图像并通过awt打印的代码如下：

    public class PrinterService implements Printable {

    private PrinterJob printerJob;
    private PageFormat pageFormat;
    private Paper paper;
    private final int MARGIN = 1;

    public PrinterService() {
        printerJob = PrinterJob.getPrinterJob();
        pageFormat = printerJob.defaultPage(); // Getting the page format.
        paper = new Paper(); // Create a new paper...

        paper.setImageableArea(MARGIN, MARGIN, pageFormat.getWidth(), pageFormat.getHeight());
        pageFormat.setPaper(paper);
        pageFormat.setOrientation(PageFormat.PORTRAIT);
        printerJob.setPrintable(this, pageFormat);
        try {
            printerJob.print();
        } catch (PrinterException ex) {
            JOptionPane.showMessageDialog(null, "Printing Failed, Error: " + ex.toString());
        }
    }

    @Override
    public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
        if (pageIndex > 0) {
            return NO_SUCH_PAGE;
        }

        float marginTop = (float) 70.83;
        Graphics2D g2d = (Graphics2D) graphics;
        ImageIcon imageIcon = new ImageIcon("qrcode75b75.gif");
        Image image = imageIcon.getImage();
        g2d.drawImage(image, 20, (int) (marginTop + 10), imageIcon.getImageObserver());
        g2d.translate(pageFormat.getImageableX(), pageFormat.getImageableY());
        return PAGE_EXISTS;
    }

}

Answer 1

一般的解决办法是用打印机在纸上印上一个停止标记，它是纸卷上的一个黑点，打印机读取黑点并了解对齐情况。