Question

我正在尝试打印JPanel ...我有工作代码。但问题是，它正在从四面打印带有广泛的magin的JPanel ... Plz有人检查我的代码。并建议我，如何更改我的代码，适用于具有最小边距的A4尺寸纸张。这个代码为actioperformed

btnNewButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        PrinterJob pjob = PrinterJob.getPrinterJob();
        PageFormat preformat = pjob.defaultPage();
        preformat.setOrientation(PageFormat.PORTRAIT);
        PageFormat postformat = pjob.pageDialog(preformat);

        if (preformat != postformat) {
            RepairBill r=new RepairBill();
            r.setVisible(false);
            pjob.setPrintable(new Printer(r.r), postformat); //r.r is the object for JPanel
            if (pjob.printDialog()) {
                try {
                    pjob.print();
                } catch (PrinterException e1) {
                        // TODO Auto-generated catch block
                        e1.printStackTrace();
                    }
                }
            }
        }
    });

打印机类代码

public static class Printer implements Printable {
    final Component comp;

    public Printer(Component comp) {
        this.comp = comp;
    }

    @Override
    public int print(Graphics g, PageFormat format, int page_index) throws PrinterException {
        if (page_index > 0) {
            return Printable.NO_SUCH_PAGE;
        }

        // get the bounds of the component
        Dimension dim = comp.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, yRatio);
        comp.paint(g2);
        return Printable.PAGE_EXISTS;
    }
}

plz see the screenshot of my output

Answer 1

我添加了边距：水平1英寸，垂直0.5英寸。

检查边距是否仍可打印（1 mm边距不可行）。

我所做的页面大小没有受到影响，因为这是一个物理设备问题，例如，有人有A4或US Letter。可以在PrintJob中设置它，查看API，网络中的javadoc。

现在按比例缩放。

    // get the bounds of the component
    Dimension dim = comp.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 paperHeight = format.getHeight();
    double paperWidth = format.getWidth();

    final int INCH = 72;
    double vertMargin = 0.5 * INCH;
    double horMargin = 1 * INCH;

    // Check whether margins are enough, are printable.
    if (paperWidth - 2 * horMargin < pWidth) {
        pWidth = paperWidth - 2 * horMargin;
        pXStart = horMargin
    }
    if (paperHeight - 2 * vertMargin < pHeight) {
        pHeight = paperHeight - 2 * vertMargin;
        pYStart = vertMargin;
    }

    // Determine scaling
    double xRatio = pWidth / cWidth;
    double yRatio = pHeight / cHeight;
    double ratio = Math.min(xRatio, yRation); // Proportional

    Graphics2D g2 = (Graphics2D) g;
    g2.translate(pXStart, pYStart);
    g2.scale(ratio, ratio);
    comp.paint(g2);

设置边距以在Java代码中打印

1 个答案: