设置jLabel的打印尺寸并在打印件上放置jRadiobutton

时间：2014-03-07 04:49:33

标签： java swing jlabel jradiobutton

我有一个带有Icon的jLabel我应该打印。但是，我无法将jLabel的图标变为全尺寸。

以下是我认为影响打印尺寸的一些代码。

 public static void printComponentToFile(Component comp, boolean fill) throws PrinterException {
    Paper paper = new Paper();
    paper.setSize(8.3 * 72, 11.7 * 72); //here
    paper.setImageableArea(18, 18, 100, 300); //and here

    PageFormat pf = new PageFormat();
    pf.setPaper(paper);
    pf.setOrientation(PageFormat.LANDSCAPE);

    BufferedImage img = new BufferedImage(
            (int) Math.round(pf.getWidth()),
            (int) Math.round(pf.getHeight()),
            BufferedImage.TYPE_INT_RGB);

    Graphics2D g2d = img.createGraphics();
    g2d.setColor(Color.WHITE);
    g2d.fill(new Rectangle(0, 0, img.getWidth(), img.getHeight()));
    ComponentPrinter cp = new ComponentPrinter(comp, fill);
    try {
        cp.print(g2d, pf, 0);
    } finally {
        g2d.dispose();
    }

    try {
        ImageIO.write(img, "png", new File("Page-" + (fill ? "Filled" : "") + ".png"));
    } catch (IOException ex) {
        ex.printStackTrace();
    }
}

public static class ComponentPrinter implements Printable {

    private Component comp;
    private boolean fill;

    public ComponentPrinter(Component comp, boolean fill) {
        this.comp = comp;
        this.fill = fill;
    }

    @Override
    public int print(Graphics g, PageFormat format, int page_index) throws PrinterException {

        if (page_index > 0) {
            return Printable.NO_SUCH_PAGE;
        }

        Graphics2D g2 = (Graphics2D) g;
        g2.translate(format.getImageableX(), format.getImageableY());

        double width = (int) Math.floor(format.getImageableWidth()); // here too
        double height = (int) Math.floor(format.getImageableHeight()); // and here

        if (!fill) {

            width = Math.min(width, comp.getPreferredSize().width); // here
            height = Math.min(height, comp.getPreferredSize().height); // here

        }

        comp.setBounds(0, 0, (int) Math.floor(width), (int) Math.floor(height));
        if (comp.getParent() == null) {
            comp.addNotify();
        }
        comp.validate();
        comp.doLayout();
        comp.printAll(g2);
        if (comp.getParent() != null) {
            comp.removeNotify();
        }

        return Printable.PAGE_EXISTS;
    }

}

那么我应该改变什么呢？另外，如何在打印过程中放置​​单选按钮？这是因为我想用标签打印出无线电按钮。

这是我使用按钮打印标签的方式：

  private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    try {       
        printComponent(jLabel2, false);
    } catch (PrinterException ex) {
        Logger.getLogger(MappingScreen.class.getName()).log(Level.SEVERE, null, ex);
    }

}

我可以这样做吗？：

  private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    try {       
        printComponent(jLabel2, false);
        printComponent(jRadioBtn1, false); //change
    } catch (PrinterException ex) {
        Logger.getLogger(M.class.getName()).log(Level.SEVERE, null, ex);
    }

}

更新：

我想我必须在这里添加一些内容来打印另一个组件：

 public static void main(String args[]) {
    try {
        JLabel label = new JLabel(
                "This is a test",
                new ImageIcon("/adv/mapp.jpg"),
                JLabel.CENTER);
        printComponentToFile(label, true);
        printComponentToFile(label, false);
    } catch (PrinterException exp) {
        exp.printStackTrace();
    }

请帮忙。谢谢

3 个答案:

答案 0 :(得分：4)

所以，基于Printing a JFrame and its components中提出的概念，我已经能够产生这两个例子......

Normal Filled

使用以下JPanel作为基本组件...... 

public static class PrintForm extends JPanel {

    public PrintForm() {
        setLayout(new GridBagLayout());
        JLabel label = new JLabel("This is a label");
        label.setVerticalTextPosition(JLabel.BOTTOM);
        label.setHorizontalTextPosition(JLabel.CENTER);
        try {
            label.setIcon(new ImageIcon(ImageIO.read(new File("C:\\hold\\thumbnails\\_cg_1009___Afraid___by_Serena_Clearwater.png"))));
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.weightx = 1;
        gbc.weighty = 1;
        add(label, gbc);

        JRadioButton rb = new JRadioButton("Open to suggestions");
        rb.setSelected(true);
        gbc.gridy++;
        gbc.weightx = 1;
        gbc.fill = GridBagConstraints.NONE;
        add(rb, gbc);
    }

}

根据Fit/Scale JComponent to page being printed中提出的概念，我能够拍摄7680x4800的图像并将其缩小以在842x598的范围内打印。

现在请注意。 JLabel不支持扩展。如果您的图像不适合可用空间，您将不得不自己进行缩放。以下解决方案对整个组件进行了扩展，尽管如此，通过一些巧妙的重新安排，可以使TestPane缩放它的图像而不是使用上面的示例......

Scaled 

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.awt.print.PageFormat;
import java.awt.print.Paper;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class ScalablePrintingTest {

    public static void main(String[] args) {
        new ScalablePrintingTest();
    }

    public ScalablePrintingTest() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                final TestPane imagePane = new TestPane();
                JButton print = new JButton("Print");
                print.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        try {
                            //printComponent(imagePane);
                            printComponentToFile(imagePane);
                        } catch (PrinterException ex) {
                            ex.printStackTrace();
                        }
                    }
                });

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(imagePane);
                frame.add(print, BorderLayout.SOUTH);
                frame.setSize(200, 200);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private BufferedImage bg;

        public TestPane() {
            try {
                bg = ImageIO.read(new File("/path/to/a/image"));
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }

        @Override
        public Dimension getPreferredSize() {
            return bg == null ? new Dimension(200, 200) : new Dimension(bg.getWidth(), bg.getHeight());
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            if (bg != null) {
                int x = (getWidth() - bg.getWidth()) / 2;
                int y = (getHeight() - bg.getHeight()) / 2;
                g2d.drawImage(bg, x, y, this);
            }
            g2d.dispose();
        }
    }

    public void printComponent(Component comp) {
        PrinterJob pj = PrinterJob.getPrinterJob();
        pj.setJobName(" Print Component ");

        pj.setPrintable(new ComponentPrintable(comp));

        if (!pj.printDialog()) {
            return;
        }
        try {
            pj.print();
        } catch (PrinterException ex) {
            System.out.println(ex);
        }
    }

    public static void printComponentToFile(Component comp) throws PrinterException {
        Paper paper = new Paper();
        paper.setSize(8.3 * 72, 11.7 * 72);
        paper.setImageableArea(18, 18, 559, 783);

        PageFormat pf = new PageFormat();
        pf.setPaper(paper);
        pf.setOrientation(PageFormat.LANDSCAPE);

        BufferedImage img = new BufferedImage(
                (int) Math.round(pf.getWidth()),
                (int) Math.round(pf.getHeight()),
                BufferedImage.TYPE_INT_RGB);

        Graphics2D g2d = img.createGraphics();
        g2d.setColor(Color.WHITE);
        g2d.fill(new Rectangle(0, 0, img.getWidth(), img.getHeight()));
        ComponentPrintable cp = new ComponentPrintable(comp);
        try {
            cp.print(g2d, pf, 0);
        } finally {
            g2d.dispose();
        }

        try {
            ImageIO.write(img, "png", new File("Page-Scaled.png"));
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    public static class ComponentPrintable implements Printable {

        private Component comp;

        private ComponentPrintable(Component comp) {
            this.comp = comp;
        }

        @Override
        public int print(Graphics g, PageFormat pf, int pageNumber)
                throws PrinterException {
            // TODO Auto-generated method stub
            if (pageNumber > 0) {
                return Printable.NO_SUCH_PAGE;
            }

            // Get the preferred size ofthe component...
            Dimension compSize = comp.getPreferredSize();
            // Make sure we size to the preferred size
            comp.setSize(compSize);
            // Get the the print size
            Dimension printSize = new Dimension();
            printSize.setSize(pf.getImageableWidth(), pf.getImageableHeight());

            // Calculate the scale factor
            double scaleFactor = getScaleFactorToFit(compSize, printSize);
            // Don't want to scale up, only want to scale down
            if (scaleFactor > 1d) {
                scaleFactor = 1d;
            }

            // Calcaulte the scaled size...
            double scaleWidth = compSize.width * scaleFactor;
            double scaleHeight = compSize.height * scaleFactor;

            // Create a clone of the graphics context.  This allows us to manipulate
            // the graphics context without begin worried about what effects
            // it might have once we're finished
            Graphics2D g2 = (Graphics2D) g.create();
            // Calculate the x/y position of the component, this will center
            // the result on the page if it can
            double x = ((pf.getImageableWidth() - scaleWidth) / 2d) + pf.getImageableX();
            double y = ((pf.getImageableHeight() - scaleHeight) / 2d) + pf.getImageableY();
            // Create a new AffineTransformation
            AffineTransform at = new AffineTransform();
            // Translate the offset to out "center" of page
            at.translate(x, y);
            // Set the scaling
            at.scale(scaleFactor, scaleFactor);
            // Apply the transformation
            g2.transform(at);
            // Print the component
            comp.printAll(g2);
            // Dispose of the graphics context, freeing up memory and discarding
            // our changes
            g2.dispose();

            comp.revalidate();
            return Printable.PAGE_EXISTS;
        }
    }

    public static double getScaleFactorToFit(Dimension original, Dimension toFit) {
        double dScale = 1d;
        if (original != null && toFit != null) {
            double dScaleWidth = getScaleFactor(original.width, toFit.width);
            double dScaleHeight = getScaleFactor(original.height, toFit.height);
            dScale = Math.min(dScaleHeight, dScaleWidth);
        }
        return dScale;
    }

    public static double getScaleFactor(int iMasterSize, int iTargetSize) {
        double dScale = 1;
        if (iMasterSize > iTargetSize) {
            dScale = (double) iTargetSize / (double) iMasterSize;
        } else {
            dScale = (double) iTargetSize / (double) iMasterSize;
        }
        return dScale;
    }
}

答案 1 :(得分：2)

我打算更新我以前的答案，但已被接受......

此示例基本上结合了Fit/Scale JComponent to page being printed和Printing a JFrame and its components中提供的解决方案，并演示了在打印组件时将组件缩放以使组件能够自行缩放的区别...

它会创建interface Printable的{​​{1}}链，我希望这有助于消除任何混淆......好吧，那就少了......

首先......

SplitScreen

左侧的面板是静态的，也就是说，组件不会缩放图像。右侧的面板是动态的，也就是说，当组件的大小发生变化时，组件将缩放图像。

使用缩放方法打印时的静态面板。您会注意到标签和单选按钮也已缩放

Static-Scaled

与使用填充方法时的动态面板相比。您会注意到标签和单选按钮没有缩放，但保持正常大小，但背景图像会缩放...

Dynmic-Filled 

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.awt.print.PageFormat;
import java.awt.print.Paper;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class PrintComponentTest {

    public static void main(String[] args) {
        new PrintComponentTest();
    }

    public PrintComponentTest() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private StaticImagePane staticImagePane;
        private DynamicImagePane dynamicImagePane;

        public TestPane() {
            JPanel content = new JPanel(new GridLayout());
            content.add(new JScrollPane(preparePane(staticImagePane = new StaticImagePane())));
            content.add(preparePane(dynamicImagePane = new DynamicImagePane()));

            setLayout(new BorderLayout());
            add(content);

            JPanel options = new JPanel();
            JButton normal = new JButton("Print");

            normal.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    try {
                        printComponentToFile(new FillableCompentPrintable(staticImagePane, false), new File("Static-Normal.png"));
                        printComponentToFile(new FillableCompentPrintable(staticImagePane, true), new File("Static-Filled.png"));
                        printComponentToFile(new ScalableCompentPrintable(staticImagePane), new File("Static-Scaled.png"));
                        printComponentToFile(new FillableCompentPrintable(dynamicImagePane, false), new File("Dynamic-Normal.png"));
                        printComponentToFile(new FillableCompentPrintable(dynamicImagePane, true), new File("Dynamic-Filled.png"));
                        printComponentToFile(new ScalableCompentPrintable(dynamicImagePane), new File("Dynamic-Scaled.png"));
                        staticImagePane.invalidate();
                        dynamicImagePane.invalidate();
                        staticImagePane.revalidate();
                        dynamicImagePane.revalidate();

                        invalidate();
                        revalidate();
                    } catch (PrinterException ex) {
                        ex.printStackTrace();
                    }
                }
            });

            options.add(normal);

            add(options, BorderLayout.SOUTH);
        }

        protected JPanel preparePane(JPanel panel) {

            panel.setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridwidth = GridBagConstraints.REMAINDER;
            JLabel label = new JLabel("This is some text on a label");
            label.setForeground(Color.WHITE);
            panel.add(label, gbc);
            JRadioButton btn = new JRadioButton("Do you agree", true);
            btn.setOpaque(false);
            btn.setForeground(Color.WHITE);
            panel.add(btn, gbc);

            return panel;

        }

    }

    public void printComponent(ComponentPrintable printable) {
        PrinterJob pj = PrinterJob.getPrinterJob();
        pj.setJobName(" Print Component ");

        pj.setPrintable(printable);

        if (!pj.printDialog()) {
            return;
        }
        try {
            pj.print();
        } catch (PrinterException ex) {
            System.out.println(ex);
        }
    }

    public static void printComponentToFile(ComponentPrintable printable, File file) throws PrinterException {
        Paper paper = new Paper();
        paper.setSize(8.3 * 72, 11.7 * 72);
        paper.setImageableArea(18, 18, 559, 783);

        PageFormat pf = new PageFormat();
        pf.setPaper(paper);
        pf.setOrientation(PageFormat.LANDSCAPE);

        BufferedImage img = new BufferedImage(
                (int) Math.round(pf.getWidth()),
                (int) Math.round(pf.getHeight()),
                BufferedImage.TYPE_INT_RGB);

        Graphics2D g2d = img.createGraphics();
        g2d.setColor(Color.WHITE);
        g2d.fill(new Rectangle(0, 0, img.getWidth(), img.getHeight()));
        try {
            printable.print(g2d, pf, 0);
        } finally {
            g2d.dispose();
        }

        try {
            ImageIO.write(img, "png", file);
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    public static interface ComponentPrintable extends Printable {

        public Component getComponent();
    }

    public abstract static class AbstractComponentPrintable implements ComponentPrintable {

        private final Component component;

        public AbstractComponentPrintable(Component component) {
            this.component = component;
        }

        @Override
        public Component getComponent() {
            return component;
        }

        protected void beforePrinting(Component comp) {
            if (comp.getParent() == null) {
                comp.addNotify();
            }
            comp.invalidate();
            comp.revalidate();
            comp.doLayout();
        }

        protected void afterPrinting(Component comp) {
            if (comp.getParent() != null) {
                comp.removeNotify();
            } else {
                comp.invalidate();
                comp.revalidate();
            }
        }

        @Override
        public int print(Graphics g, PageFormat format, int page_index) throws PrinterException {

            if (page_index > 0) {
                return Printable.NO_SUCH_PAGE;
            }

            Graphics2D g2 = (Graphics2D) g;
            printComponent(g2, format, getComponent());

            return Printable.PAGE_EXISTS;
        }

        protected abstract void printComponent(Graphics2D g, PageFormat pf, Component comp);
    }

    public static class FillableCompentPrintable extends AbstractComponentPrintable {

        private boolean fill;

        public FillableCompentPrintable(Component component, boolean fill) {
            super(component);
            this.fill = fill;
        }

        public boolean isFill() {
            return fill;
        }

        @Override
        protected void printComponent(Graphics2D g2, PageFormat pf, Component comp) {
            g2.translate(pf.getImageableX(), pf.getImageableY());

            double width = (int) Math.floor(pf.getImageableWidth());
            double height = (int) Math.floor(pf.getImageableHeight());

            if (!isFill()) {

                width = Math.min(width, comp.getPreferredSize().width);
                height = Math.min(height, comp.getPreferredSize().height);

            }

            comp.setBounds(0, 0, (int) Math.floor(width), (int) Math.floor(height));
            beforePrinting(comp);
            comp.printAll(g2);
            afterPrinting(comp);

            // Debug purposes only...
            g2.translate(-pf.getImageableX(), -pf.getImageableY());
            g2.setColor(Color.RED);
            g2.drawRect(0, 0, (int) pf.getWidth() - 1, (int) pf.getHeight() - 1);

        }

    }

    public static class ScalableCompentPrintable extends AbstractComponentPrintable {

        public ScalableCompentPrintable(Component component) {
            super(component);
        }

        @Override
        protected void printComponent(Graphics2D g2d, PageFormat pf, Component comp) {
// Get the preferred size ofthe component...
            Dimension compSize = comp.getPreferredSize();
            // Make sure we size to the preferred size
            comp.setSize(compSize);
            // Get the the print size
            Dimension printSize = new Dimension();
            printSize.setSize(pf.getImageableWidth(), pf.getImageableHeight());

            // Calculate the scale factor
            double scaleFactor = getScaleFactorToFit(compSize, printSize);
            // Don't want to scale up, only want to scale down
            if (scaleFactor > 1d) {
                scaleFactor = 1d;
            }

            // Calcaulte the scaled size...
            double scaleWidth = compSize.width * scaleFactor;
            double scaleHeight = compSize.height * scaleFactor;

            // Create a clone of the graphics context.  This allows us to manipulate
            // the graphics context without begin worried about what effects
            // it might have once we're finished
            Graphics2D g2 = (Graphics2D) g2d.create();
            // Calculate the x/y position of the component, this will center
            // the result on the page if it can
            double x = ((pf.getImageableWidth() - scaleWidth) / 2d) + pf.getImageableX();
            double y = ((pf.getImageableHeight() - scaleHeight) / 2d) + pf.getImageableY();
            // Create a new AffineTransformation
            AffineTransform at = new AffineTransform();
            // Translate the offset to out "center" of page
            at.translate(x, y);
            // Set the scaling
            at.scale(scaleFactor, scaleFactor);
            // Apply the transformation
            g2.transform(at);
            // Print the component
            beforePrinting(comp);
            comp.printAll(g2);
            afterPrinting(comp);
            // Dispose of the graphics context, freeing up memory and discarding
            // our changes
            g2.dispose();

            // Debug purposes only...
            g2d.setColor(Color.RED);
            g2d.drawRect(0, 0, (int) pf.getWidth() - 1, (int) pf.getHeight() - 1);
        }

        public static double getScaleFactorToFit(Dimension original, Dimension toFit) {
            double dScale = 1d;
            if (original != null && toFit != null) {
                double dScaleWidth = getScaleFactor(original.width, toFit.width);
                double dScaleHeight = getScaleFactor(original.height, toFit.height);
                dScale = Math.min(dScaleHeight, dScaleWidth);
            }
            return dScale;
        }

        public static double getScaleFactor(int iMasterSize, int iTargetSize) {
            double dScale = 1;
            if (iMasterSize > iTargetSize) {
                dScale = (double) iTargetSize / (double) iMasterSize;
            } else {
                dScale = (double) iTargetSize / (double) iMasterSize;
            }
            return dScale;
        }
    }

    public class StaticImagePane extends JPanel {

        private BufferedImage image;

        public StaticImagePane() {
            try {
                setImage(ImageIO.read(new File("path\to\a\image")));
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }

        public BufferedImage getImage() {
            return image;
        }

        public void setImage(BufferedImage image) {
            this.image = image;
            repaint();
        }

        @Override
        public Dimension getPreferredSize() {
            BufferedImage bg = getImage();
            return bg == null ? new Dimension(200, 200) : new Dimension(bg.getWidth(), bg.getHeight());
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            paintBackground(g2d);
            g2d.dispose();
        }

        protected void paintBackground(Graphics2D g2d) {
            paintBackground(g2d, getImage());
        }

        protected void paintBackground(Graphics2D g2d, Image bg) {
            if (bg != null) {
                int x = (getWidth() - bg.getWidth(this)) / 2;
                int y = (getHeight() - bg.getHeight(this)) / 2;
                g2d.drawImage(bg, x, y, this);
            }
        }

    }

    public class DynamicImagePane extends StaticImagePane {

        private Image scaled;

        public DynamicImagePane() {
            try {
                setImage(ImageIO.read(new File("path\to\a\image")));
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }

        @Override
        public void invalidate() {
            super.invalidate();
            if (getImage() != null) {
                int width = getWidth();
                int height = getHeight();
                if (width > 0 && height > 0) {
                    // Keep the aspect ratio
                    if (width > height) {
                        width = -1;
                    } else if (height > width) {
                        height = -1;
                    }
                    scaled = getImage().getScaledInstance(width, height, Image.SCALE_SMOOTH);
                }
            }
        }

        public Image getScaledImage() {
            return scaled;
        }

        @Override
        protected void paintBackground(Graphics2D g2d) {
            paintBackground(g2d, getScaledImage());
        }

    }

}

请注意，这只是一个例子，需要做很多工作。

一个问题是缩放，有关详细信息，请参阅The Perils of Image.getScaledInstance();有关更好的方法，请参见Quality of Image after resize very low -- Java ...

答案 2 :(得分：1)

为了使其有效，我将其更改为：

  //OLD: 
   public void printComponent(Component comp) {


   //NEW:

   public void printComponent(JComponent comp, boolean fill) throws PrinterException { 

    PrinterJob pj = PrinterJob.getPrinterJob();
    pj.setJobName(" Print Component ");

    pj.setPrintable(new ComponentPrintable(comp));

    if (!pj.printDialog()) {
        return;
    }
    try {
        pj.print();
    } catch (PrinterException ex) {
        System.out.println(ex);
    }
}
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