Question

我有JPanel，JDialog打印预览，无误播放但 pack（）; 后无法显示。

我知道它有点长，但你可以跳到PrintPreview 方法，其他人只是知道我如何控制的更多细节。

请帮助，我不知道为什么它不会出现在屏幕上。 任何人都非常感谢你们。 ^ _ ^

private PageFormat pf;
private Book pg;
private int pageIndex;
private int totalPages;
private double scaler;

private String title;
private JTextField pageInput;
private JTextField zoomInput;
private PreviewPanel pp;
private JLabel statusBar;

从这里开始

public void PrintPreview(String title, Book pg, int pageIndex) {
    this.title = title;
    setTitle(title + " - Print Preview");
    scaler = .5;
    this.pg = pg;
    this.pageIndex = pageIndex;
    this.totalPages = pg.getNumberOfPages();
    pf = pg.getPageFormat(pageIndex);
    setModalityType(Dialog.ModalityType.APPLICATION_MODAL);
    setLayout(new BorderLayout());
    pp = new PreviewPanel();
    add(new JScrollPane(pp), BorderLayout.CENTER);

    JPanel topBar = new JPanel();
    topBar.setLayout(new BorderLayout());
    add(topBar, BorderLayout.NORTH);
    JPanel leftTop = new JPanel();
    JPanel rightTop = new JPanel();
    topBar.add(leftTop, BorderLayout.WEST);
    topBar.add(rightTop, BorderLayout.EAST);

    leftTop.add(new JLabel("Page:"));
    Insets pageButtonInsets = new Insets(0, 2, 0, 2);
    JButton pageBack = new JButton("<");
    pageBack.setMargin(pageButtonInsets);
    pageBack.setActionCommand("back");
    pageBack.addActionListener(this);
    JButton pageForward = new JButton(">");
    pageForward.setMargin(pageButtonInsets);
    pageForward.setActionCommand("forward");
    pageForward.addActionListener(this);
    pageInput = new JTextField(Integer.toString(pageIndex+1));
    pageInput.setPreferredSize(new Dimension(30, 20));
    pageInput.setActionCommand("page");
    pageInput.addActionListener(this);
    leftTop.add(pageBack);
    leftTop.add(pageInput);
    leftTop.add(pageForward);
    rightTop.add(new JLabel("Zoom:"));
    zoomInput = new JTextField((int)(scaler*100)+"%");
    zoomInput.setPreferredSize(new Dimension(30, 20));
    rightTop.add(zoomInput);
    JButton zoomSet = new JButton("Set");
    zoomSet.setMargin(new Insets(0, 0, 0, 0));
    zoomSet.setPreferredSize(new Dimension(30, 20));
    rightTop.add(zoomSet);
    zoomSet.setActionCommand("zoom");
    zoomSet.addActionListener(this);

    JPanel lowerBar = new JPanel();
    lowerBar.setLayout(new BorderLayout());
    lowerBar.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED));
    statusBar = new JLabel("Ag"); // temporary label for setting size of status bar
    lowerBar.add(statusBar, BorderLayout.CENTER);
    add(lowerBar, BorderLayout.SOUTH);

    JButton license = new JButton("<html>&copy;</html>");
    license.setActionCommand("license");
    license.setMargin(new Insets(0, 0, 0, 0));
    license.addActionListener(this);
    lowerBar.add(license, BorderLayout.WEST);

    JButton print = new JButton("Print...");
    print.setActionCommand("print");
    print.setMargin(new Insets(4, 0, 4, 0));
    print.addActionListener(this);
    lowerBar.add(print, BorderLayout.EAST);
    pack();
    //setVisible(true);
}

在此结束

private void updateStatusBar() {
    updateStatusBar("Page " + (pageIndex+1) + " of " + totalPages);
}
private void updateStatusBar(String s) {
    updateStatusBar(s, Color.black);
}
private void updateStatusBar(String s, Color c) {
    statusBar.setText(s);
    statusBar.setForeground(c);
}

private void print() {
    PrinterJob pj = PrinterJob.getPrinterJob();
    pj.setPageable(pg);
    pj.setJobName(title);
    if (pj.printDialog()) {
        try {
            pj.print();
        } catch (PrinterException e) {
            e.printStackTrace();
            JOptionPane.showMessageDialog(this, "Could not print.\nSee the Java error console for details.", "error", JOptionPane.ERROR_MESSAGE);
        }
    }
}

private class PreviewPanel extends JPanel {
    private static final long serialVersionUID = 1L;

    public PreviewPanel() {
        resetPreferredSize();
    }

    public void resetPreferredSize() {
        setPreferredSize(new Dimension((int)(pf.getWidth()*scaler), (int)(pf.getHeight()*scaler)));
    }

    public void paintComponent(Graphics g1) {
        Graphics2D g = (Graphics2D)g1;
        g.setColor(Color.black);
        g.fillRect(0, 0, getWidth(), getHeight());
        g.setColor(Color.white);
        g.fillRect(0, 0, (int)(pf.getWidth()*scaler), (int)(pf.getHeight()*scaler));
        g.setColor(Color.black);
        try {
            g.scale(scaler, scaler);
            pg.getPrintable(pageIndex).print(g, pf, pageIndex);
            updateStatusBar();
        } catch (IndexOutOfBoundsException e) {
            e.printStackTrace();
            g.setFont(new Font("Helvetica", Font.ITALIC, 30));
            g.drawString("Page index out of range", 10, 30);
            updateStatusBar("Page index out of range", Color.red);
        } catch (PrinterException e) {
            e.printStackTrace();
            g.setFont(new Font("Helvetica", Font.ITALIC, 30));
            g.drawString("Printer error", 10, 30);
            updateStatusBar("Printer error", Color.red);
        }
    }       
}

@Override
public void actionPerformed(ActionEvent arg0) {
    if (arg0.getActionCommand().equals("page")) {
        // change page
        try {
            pageIndex = Integer.parseInt(pageInput.getText())-1;
            pp.repaint();
        } catch (NumberFormatException e) {
            // do nothing if the entry is not a number
        }
    } else if (arg0.getActionCommand().equals("back")) {
        if (pageIndex > 0) {
            pageIndex--;
            pageInput.setText(Integer.toString(pageIndex+1));
            pp.repaint();
        }
    } else if (arg0.getActionCommand().equals("forward")) {
        if (pageIndex < totalPages - 1) {
            pageIndex++;
            pageInput.setText(Integer.toString(pageIndex+1));
            pp.repaint();
        }
    } else if (arg0.getActionCommand().equals("zoom")) {
        // change zoom setting
        try {
            scaler = Double.parseDouble(zoomInput.getText().replaceAll("%", ""))// 100.0;
            pp.resetPreferredSize();
            pp.revalidate();
            pp.repaint();
        } catch (NumberFormatException e) {
            // do nothing if the entry is not a number
        }
    } else if (arg0.getActionCommand().equals("license")) {
        JOptionPane.showMessageDialog(this, LICENSE);
    } else if (arg0.getActionCommand().equals("print")) {
        print();
    }
}

Answer 1

是的，我明白了。哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈！

打印预览（包不起作用）

1 个答案: