Java GUI 打印空白页

Question

我正在使用 Java GUI，并且想要打印单个面板。我收到提示，我得到了一些要打印的东西，但问题是有些东西只是一张空白页。

以下是所有相关代码:

public class DrawPanel extends JPanel implements MouseMotionListener, Printable {

...

public void print(){
        PrinterJob job = PrinterJob.getPrinterJob();
        job.setPrintable(this);
        if(job.printDialog()){
            try{
                job.print();
            }catch(PrinterException e){
                System.err.print("Print failed: " + e);}

        }
    }

...

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

        Graphics2D g = (Graphics2D)graphics;
        g.translate(pageFormat.getImageableX(), pageFormat.getImageableY());
        this.setDoubleBuffered(false);
        this.paint(g);

        return PAGE_EXISTS;

    }

然后在另一个调用该函数的对象中:

if(evt.getSource() == btn_print){

    p.print();

}

Answer 1

  public class PrintView extends FrameView implements Printable,ActionListener{

public PrintView(SingleFrameApplication app) throws PrinterException {
    super(app);

    initComponents();

    jButton1.addActionListener(this);


    // status bar initialization - message timeout, idle icon and busy animation, etc
    ResourceMap resourceMap = getResourceMap();
    int messageTimeout = resourceMap.getInteger("StatusBar.messageTimeout");
    messageTimer = new Timer(messageTimeout, new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            statusMessageLabel.setText("");
        }
    });
    messageTimer.setRepeats(false);
    int busyAnimationRate = resourceMap.getInteger("StatusBar.busyAnimationRate");
    for (int i = 0; i < busyIcons.length; i++) {
        busyIcons[i] = resourceMap.getIcon("StatusBar.busyIcons[" + i + "]");
    }
    busyIconTimer = new Timer(busyAnimationRate, new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            busyIconIndex = (busyIconIndex + 1) % busyIcons.length;
            statusAnimationLabel.setIcon(busyIcons[busyIconIndex]);
        }
    });
    idleIcon = resourceMap.getIcon("StatusBar.idleIcon");
    statusAnimationLabel.setIcon(idleIcon);
    progressBar.setVisible(false);

    // connecting action tasks to status bar via TaskMonitor
    TaskMonitor taskMonitor = new TaskMonitor(getApplication().getContext());
    taskMonitor.addPropertyChangeListener(new java.beans.PropertyChangeListener() {
        public void propertyChange(java.beans.PropertyChangeEvent evt) {
            String propertyName = evt.getPropertyName();
            if ("started".equals(propertyName)) {
                if (!busyIconTimer.isRunning()) {
                    statusAnimationLabel.setIcon(busyIcons[0]);
                    busyIconIndex = 0;
                    busyIconTimer.start();
                }
                progressBar.setVisible(true);
                progressBar.setIndeterminate(true);
            } else if ("done".equals(propertyName)) {
                busyIconTimer.stop();
                statusAnimationLabel.setIcon(idleIcon);
                progressBar.setVisible(false);
                progressBar.setValue(0);
            } else if ("message".equals(propertyName)) {
                String text = (String)(evt.getNewValue());
                statusMessageLabel.setText((text == null) ? "" : text);
                messageTimer.restart();
            } else if ("progress".equals(propertyName)) {
                int value = (Integer)(evt.getNewValue());
                progressBar.setVisible(true);
                progressBar.setIndeterminate(false);
                progressBar.setValue(value);
            }
        }
    });
}

@Action
public void showAboutBox() {
    if (aboutBox == null) {
        JFrame mainFrame = PrintApp.getApplication().getMainFrame();
        aboutBox = new PrintAboutBox(mainFrame);
        aboutBox.setLocationRelativeTo(mainFrame);
    }
    PrintApp.getApplication().show(aboutBox);
}

/** This method is called from within the constructor to
 * initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is
 * always regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    mainPanel = new javax.swing.JPanel();
    jButton1 = new javax.swing.JButton();
    jPanel1 = new javax.swing.JPanel();
    jLabel1 = new javax.swing.JLabel();
    jComboBox1 = new javax.swing.JComboBox();
    jSlider1 = new javax.swing.JSlider();
    jProgressBar1 = new javax.swing.JProgressBar();
    jPasswordField1 = new javax.swing.JPasswordField();
    menuBar = new javax.swing.JMenuBar();
    javax.swing.JMenu fileMenu = new javax.swing.JMenu();
    javax.swing.JMenuItem exitMenuItem = new javax.swing.JMenuItem();
    javax.swing.JMenu helpMenu = new javax.swing.JMenu();
    javax.swing.JMenuItem aboutMenuItem = new javax.swing.JMenuItem();
    statusPanel = new javax.swing.JPanel();
    javax.swing.JSeparator statusPanelSeparator = new javax.swing.JSeparator();
    statusMessageLabel = new javax.swing.JLabel();
    statusAnimationLabel = new javax.swing.JLabel();
    progressBar = new javax.swing.JProgressBar();

    mainPanel.setName("mainPanel"); // NOI18N

    org.jdesktop.application.ResourceMap resourceMap = org.jdesktop.application.Application.getInstance(print.PrintApp.class).getContext().getResourceMap(PrintView.class);
    jButton1.setText(resourceMap.getString("jButton1.text")); // NOI18N
    jButton1.setName("jButton1"); // NOI18N

    jPanel1.setBorder(new javax.swing.border.MatteBorder(null));
    jPanel1.setName("jPanel1"); // NOI18N

    jLabel1.setText(resourceMap.getString("jLabel1.text")); // NOI18N
    jLabel1.setName("jLabel1"); // NOI18N

    jComboBox1.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "1", "2", "3", "4" }));
    jComboBox1.setName("jComboBox1"); // NOI18N

    jSlider1.setName("jSlider1"); // NOI18N

    jProgressBar1.setName("jProgressBar1"); // NOI18N

    jPasswordField1.setText(resourceMap.getString("jPasswordField1.text")); // NOI18N
    jPasswordField1.setName("jPasswordField1"); // NOI18N

    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGap(371, 371, 371)
            .addComponent(jLabel1)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 280, Short.MAX_VALUE)
            .addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(133, 133, 133))
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
            .addContainerGap(233, Short.MAX_VALUE)
            .addComponent(jProgressBar1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(185, 185, 185)
            .addComponent(jSlider1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(97, 97, 97))
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
            .addContainerGap(486, Short.MAX_VALUE)
            .addComponent(jPasswordField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(264, 264, 264))
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGap(49, 49, 49)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                .addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(jLabel1))
            .addGap(62, 62, 62)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                .addComponent(jSlider1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(jProgressBar1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 60, Short.MAX_VALUE)
            .addComponent(jPasswordField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(32, 32, 32))
    );

    javax.swing.GroupLayout mainPanelLayout = new javax.swing.GroupLayout(mainPanel);
    mainPanel.setLayout(mainPanelLayout);
    mainPanelLayout.setHorizontalGroup(
        mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(mainPanelLayout.createSequentialGroup()
            .addGap(446, 446, 446)
            .addComponent(jButton1)
            .addContainerGap(466, Short.MAX_VALUE))
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, mainPanelLayout.createSequentialGroup()
            .addContainerGap(66, Short.MAX_VALUE)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(46, 46, 46))
    );
    mainPanelLayout.setVerticalGroup(
        mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(mainPanelLayout.createSequentialGroup()
            .addGap(107, 107, 107)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 30, Short.MAX_VALUE)
            .addComponent(jButton1)
            .addGap(56, 56, 56))
    );

    menuBar.setName("menuBar"); // NOI18N

    fileMenu.setText(resourceMap.getString("fileMenu.text")); // NOI18N
    fileMenu.setName("fileMenu"); // NOI18N

    javax.swing.ActionMap actionMap = org.jdesktop.application.Application.getInstance(print.PrintApp.class).getContext().getActionMap(PrintView.class, this);
    exitMenuItem.setAction(actionMap.get("quit")); // NOI18N
    exitMenuItem.setName("exitMenuItem"); // NOI18N
    fileMenu.add(exitMenuItem);

    menuBar.add(fileMenu);

    helpMenu.setText(resourceMap.getString("helpMenu.text")); // NOI18N
    helpMenu.setName("helpMenu"); // NOI18N

    aboutMenuItem.setAction(actionMap.get("showAboutBox")); // NOI18N
    aboutMenuItem.setName("aboutMenuItem"); // NOI18N
    helpMenu.add(aboutMenuItem);

    menuBar.add(helpMenu);

    statusPanel.setName("statusPanel"); // NOI18N

    statusPanelSeparator.setName("statusPanelSeparator"); // NOI18N

    statusMessageLabel.setName("statusMessageLabel"); // NOI18N

    statusAnimationLabel.setHorizontalAlignment(javax.swing.SwingConstants.LEFT);
    statusAnimationLabel.setName("statusAnimationLabel"); // NOI18N

    progressBar.setName("progressBar"); // NOI18N

    javax.swing.GroupLayout statusPanelLayout = new javax.swing.GroupLayout(statusPanel);
    statusPanel.setLayout(statusPanelLayout);
    statusPanelLayout.setHorizontalGroup(
        statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(statusPanelSeparator, javax.swing.GroupLayout.DEFAULT_SIZE, 975, Short.MAX_VALUE)
        .addGroup(statusPanelLayout.createSequentialGroup()
            .addContainerGap()
            .addComponent(statusMessageLabel)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 805, Short.MAX_VALUE)
            .addComponent(progressBar, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addComponent(statusAnimationLabel)
            .addContainerGap())
    );
    statusPanelLayout.setVerticalGroup(
        statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(statusPanelLayout.createSequentialGroup()
            .addComponent(statusPanelSeparator, javax.swing.GroupLayout.PREFERRED_SIZE, 2, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addGroup(statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(statusMessageLabel)
                .addComponent(statusAnimationLabel)
                .addComponent(progressBar, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
            .addGap(3, 3, 3))
    );

    setComponent(mainPanel);
    setMenuBar(menuBar);
    setStatusBar(statusPanel);
}// </editor-fold>                        

// Variables declaration - do not modify                     
private javax.swing.JButton jButton1;
private javax.swing.JComboBox jComboBox1;
private javax.swing.JLabel jLabel1;
private javax.swing.JPanel jPanel1;
private javax.swing.JPasswordField jPasswordField1;
private javax.swing.JProgressBar jProgressBar1;
private javax.swing.JSlider jSlider1;
private javax.swing.JPanel mainPanel;
private javax.swing.JMenuBar menuBar;
private javax.swing.JProgressBar progressBar;
private javax.swing.JLabel statusAnimationLabel;
private javax.swing.JLabel statusMessageLabel;
private javax.swing.JPanel statusPanel;
// End of variables declaration                   

private final Timer messageTimer;
private final Timer busyIconTimer;
private final Icon idleIcon;
private final Icon[] busyIcons = new Icon[15];
private int busyIconIndex = 0;

private JDialog aboutBox;
public void actionPerformed(ActionEvent e)
{
    if(e.getActionCommand().equals("PRINT"))
    {
            PrinterJob job = PrinterJob.getPrinterJob();
     job.setPrintable(this);
     boolean ok = job.printDialog();
         if (ok)
        {
            try
            {
              job.print();
            }
            catch (PrinterException ex)
            {
            /* The job did not successfully complete */
            }
        }
    }
}
public int print(Graphics g, PageFormat pf, int page) throws
                                                    PrinterException {

    if (page > 0) { /* We have only one page, and 'page' is zero-based */
        return NO_SUCH_PAGE;
    }

    /* User (0,0) is typically outside the imageable area, so we must
     * translate by the X and Y values in the PageFormat to avoid clipping
     */
    Graphics2D g2d = (Graphics2D)g;
    g2d.translate(pf.getImageableX(), pf.getImageableY());

    /* Now print the window and its visible contents */
   // jPanel1.printAll(g);
    jPanel1.paint(g2d);
    jPanel1.repaint();
    /* tell the caller that this page is part of the printed document */
    return PAGE_EXISTS;
 }
 }