java - 用java设计热敏打印机收据

Question

我在 Android 中有一个项目，其中我制作了一个类似于购物 list 应用程序的东西，可以打印到收据热敏打印机。我设计收据的方式很简单:我创建了一个 .xml 布局，其中为标题添加了 1 个线性布局，为列添加了 3 个垂直线性布局，为页脚添加了另一个布局。之后，我只需以编程方式将文本添加到布局中，然后然后将 .xml 发送到打印。太棒了，我可以轻松设置字体，轻松移动内容，添加图像、 Logo 等任何内容。

现在，我知道我可以使用graphics2d并打印GUI组件，我用文本区域测试了它，它工作得很好。当你有大约100行时它甚至会滚动，不像jframes，它只打印它所看到的内容。

我的问题是我需要 3-4 列文本。如下所示:

1. Bananas         4     11.20$
2. Toilet paper    12    3.99$
3. Donuts          1     0.49$

我可以将其添加到文本区域并打印它，但问题是文本的长度会有所不同，并且文本会变得困惑且不均匀。

那么，我怎样才能像在android中那样做:添加3-4列，我可以在其中添加文本，即使它们有100行，打印机也将成功打印所有行，而不是您无需向下滚动即可看到的行？

提前致谢，祝你有美好的一天!

Answer 1

经过近 6 年的时间，我终于有时间再次打开该项目，并考虑发布我最终使用的解决方案，所以这里是:

@Log4j2
@Service
public class PrintService implements Printable {

@Autowired
private PreviewManager previewManager;

public boolean printCopies() {

    final JPanel printPanel = new JPanel();
    DefaultListModel listModel = new DefaultListModel();

    printPanel.setLayout(new BoxLayout(printPanel, BoxLayout.PAGE_AXIS));
    printPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
    JLabel label = new JLabel("Select the number of copies");
    listModel.addElement("0");
    listModel.addElement("1");
    listModel.addElement("2");
    listModel.addElement("3");
    listModel.addElement("4");
    listModel.addElement("5");

    final JList list = new JList(listModel);
    list.setVisibleRowCount(1);
    list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    list.setLayoutOrientation(JList.HORIZONTAL_WRAP);

    final int[] nrOfCopies = {1};
    list.addListSelectionListener(lse -> nrOfCopies[0] = Integer.parseInt((String) list.getSelectedValue()));
    printPanel.add(label);

    printPanel.add(list);
    label.setAlignmentX(JComponent.CENTER_ALIGNMENT);
    list.setAlignmentX(JComponent.CENTER_ALIGNMENT);
    list.setSelectedIndex(1);
    JOptionPane jop = new JOptionPane(printPanel,
            JOptionPane.PLAIN_MESSAGE,
            JOptionPane.OK_CANCEL_OPTION);
    JDialog dialog = jop.createDialog(EMPTY_STRING);
    dialog.setAlwaysOnTop(true);
    dialog.addComponentListener(new ComponentAdapter() {
        @Override
        public void componentShown(ComponentEvent e) {
            SwingUtilities.invokeLater(list::requestFocusInWindow);
        }
    });
    dialog.setVisible(true);
    int result = (Integer) jop.getValue();
    dialog.dispose();

    if (result == JOptionPane.OK_OPTION) {
        log.info("Printing {} copies of the list", nrOfCopies[0]);
        for (int c = 0; c < nrOfCopies[0]; c++) {
            print();
        }
        return true;
    }
    // todo: bring back
    return false;
}

public void print() {
    PrinterJob pjob = PrinterJob.getPrinterJob();
    javax.print.PrintService[] printServices = PrintServiceLookup.lookupPrintServices(null, null);
    for (javax.print.PrintService printer : printServices) {
        // in my case I use a Star TSP143 thermal printer
        if (printer.getName().contains("tsp143")) {
            try {
                pjob.setPrintService(printer);
            } catch (PrinterException e) {
                log.error(e);
            }
        }
    }
    PageFormat preformat = pjob.defaultPage();
    preformat.setOrientation(PageFormat.PORTRAIT);
    PageFormat postformat = pjob.defaultPage(preformat);
    Paper p = preformat.getPaper();
    p.setImageableArea(0, 0, postformat.getWidth(), postformat.getHeight());
    postformat.setPaper(p);

    //If user does not hit cancel then print.
    if (preformat != postformat) {
        //Set print component
        pjob.setPrintable(PrintService.this, postformat);
        try {
            pjob.print();
        } catch (PrinterException ex) {
            log.error(ex);
        }
    }
}


@Override
public int print(Graphics g, PageFormat format, int page_index) {
    // depends on your use case, printableJpanel is going to be the panel you are going to print
    JPanel printableJpanel = previewManager.getPrintablePanel();
    if (page_index > 0) {
        return Printable.NO_SUCH_PAGE;
    }

    // get the bounds of the component
    Dimension dim = printableJpanel.getSize();
    double cHeight = dim.getHeight();
    double cWidth = dim.getWidth();

    // get the bounds of the printable area
    double pHeight = format.getImageableHeight();
    double pWidth = format.getImageableWidth();

    double pXStart = format.getImageableX();
    double pYStart = format.getImageableY();

    double xRatio = pWidth / cWidth;
    double yRatio = pHeight / cHeight;

    Graphics2D g2 = (Graphics2D) g;
    g2.translate(pXStart, pYStart);
    g2.scale(xRatio, 0.80);
    printableJpanel.paint(g2);

    return Printable.PAGE_EXISTS;

    }
}

祝你好运!