更改swing应用程序的外观（UIManager）时出错

Question

您好我有一个界面，用户可以更改外观。这是界面：

http://www.hostingpics.net/viewer.php?id=579250themesApp.jpg

和每个按钮的代码：

//The JDesktop Frame contains all the Internal Frames
JDesktop p = new JDesktop();
try {
            UIManager.setLookAndFeel( new javax.swing.plaf.metal.MetalLookAndFeel());

        SwingUtilities.updateComponentTreeUI(p);
        } catch (UnsupportedLookAndFeelException ex) {
            Logger.getLogger(paramApparence.class.getName()).log(Level.SEVERE, null, ex);
        }

对于每个按钮，我只改变外观（金属/雨云等）

当我点击按钮改变外观时，它会给我：

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException

这是完整的堆栈跟踪：

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at sun.font.FontDesignMetrics$MetricsKey.init(FontDesignMetrics.java:217)
    at sun.font.FontDesignMetrics.getMetrics(FontDesignMetrics.java:286)
    at sun.swing.SwingUtilities2.getFontMetrics(SwingUtilities2.java:1012)
    at javax.swing.JComponent.getFontMetrics(JComponent.java:1624)
    at sun.swing.MenuItemLayoutHelper.reset(MenuItemLayoutHelper.java:125)
    at javax.swing.plaf.synth.SynthMenuItemLayoutHelper.<init>(SynthMenuItemLayoutHelper.java:119)
    at javax.swing.plaf.synth.SynthGraphicsUtils.paint(SynthGraphicsUtils.java:498)
    at javax.swing.plaf.synth.SynthMenuUI.paint(SynthMenuUI.java:283)
    at javax.swing.plaf.synth.SynthMenuUI.update(SynthMenuUI.java:248)
    at javax.swing.JComponent.paintComponent(JComponent.java:778)
    at javax.swing.JComponent.paint(JComponent.java:1054)
    at javax.swing.JComponent.paintChildren(JComponent.java:887)
    at javax.swing.JComponent.paint(JComponent.java:1063)
    at javax.swing.JComponent.paintChildren(JComponent.java:887)
    at javax.swing.JComponent.paint(JComponent.java:1063)
    at javax.swing.JLayeredPane.paint(JLayeredPane.java:585)
    at javax.swing.JComponent.paintChildren(JComponent.java:887)
    at javax.swing.JComponent.paint(JComponent.java:1063)
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5221)
    at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:295)
    at javax.swing.RepaintManager.paint(RepaintManager.java:1206)
    at javax.swing.JComponent._paintImmediately(JComponent.java:5169)
    at javax.swing.JComponent.paintImmediately(JComponent.java:4980)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:770)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:728)
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:677)
    at javax.swing.RepaintManager.access$700(RepaintManager.java:59)
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1621)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:705)
    at java.awt.EventQueue.access$000(EventQueue.java:101)
    at java.awt.EventQueue$3.run(EventQueue.java:666)
    at java.awt.EventQueue$3.run(EventQueue.java:664)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:675)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at sun.font.FontDesignMetrics$MetricsKey.init(FontDesignMetrics.java:217)
    at sun.font.FontDesignMetrics.getMetrics(FontDesignMetrics.java:286)
    at sun.swing.SwingUtilities2.getFontMetrics(SwingUtilities2.java:1012)
    at javax.swing.JComponent.getFontMetrics(JComponent.java:1624)
    at sun.swing.MenuItemLayoutHelper.reset(MenuItemLayoutHelper.java:126)
    at javax.swing.plaf.synth.SynthMenuItemLayoutHelper.<init>(SynthMenuItemLayoutHelper.java:119)
    at javax.swing.plaf.synth.SynthGraphicsUtils.paint(SynthGraphicsUtils.java:498)
    at javax.swing.plaf.synth.SynthMenuItemUI.paint(SynthMenuItemUI.java:283)
    at javax.swing.plaf.synth.SynthMenuItemUI.update(SynthMenuItemUI.java:247)
    at javax.swing.JComponent.paintComponent(JComponent.java:778)
    at javax.swing.JComponent.paint(JComponent.java:1054)
    at javax.swing.JComponent.paintChildren(JComponent.java:887)
    at javax.swing.JComponent.paint(JComponent.java:1063)
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5221)
    at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:295)
    at javax.swing.RepaintManager.paint(RepaintManager.java:1206)
    at javax.swing.JComponent._paintImmediately(JComponent.java:5169)
    at javax.swing.JComponent.paintImmediately(JComponent.java:4980)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:770)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:728)
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:677)
    at javax.swing.RepaintManager.access$700(RepaintManager.java:59)
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1621)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:705)
    at java.awt.EventQueue.access$000(EventQueue.java:101)
    at java.awt.EventQueue$3.run(EventQueue.java:666)
    at java.awt.EventQueue$3.run(EventQueue.java:664)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:675)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at sun.font.FontDesignMetrics$MetricsKey.init(FontDesignMetrics.java:217)
    at sun.font.FontDesignMetrics.getMetrics(FontDesignMetrics.java:286)
    at sun.swing.SwingUtilities2.getFontMetrics(SwingUtilities2.java:1012)
    at javax.swing.JComponent.getFontMetrics(JComponent.java:1624)
    at sun.swing.MenuItemLayoutHelper.reset(MenuItemLayoutHelper.java:126)
    at javax.swing.plaf.synth.SynthMenuItemLayoutHelper.<init>(SynthMenuItemLayoutHelper.java:119)
    at javax.swing.plaf.synth.SynthGraphicsUtils.paint(SynthGraphicsUtils.java:498)
    at javax.swing.plaf.synth.SynthMenuItemUI.paint(SynthMenuItemUI.java:283)
    at javax.swing.plaf.synth.SynthMenuItemUI.update(SynthMenuItemUI.java:247)
    at javax.swing.JComponent.paintComponent(JComponent.java:778)
    at javax.swing.JComponent.paint(JComponent.java:1054)
    at javax.swing.JComponent.paintChildren(JComponent.java:887)
    at javax.swing.JComponent.paint(JComponent.java:1063)
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5221)
    at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:295)
    at javax.swing.RepaintManager.paint(RepaintManager.java:1206)
    at javax.swing.JComponent._paintImmediately(JComponent.java:5169)
    at javax.swing.JComponent.paintImmediately(JComponent.java:4980)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:770)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:728)
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:677)
    at javax.swing.RepaintManager.access$700(RepaintManager.java:59)
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1621)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:705)
    at java.awt.EventQueue.access$000(EventQueue.java:101)
    at java.awt.EventQueue$3.run(EventQueue.java:666)
    at java.awt.EventQueue$3.run(EventQueue.java:664)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:675)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

Answer 1

例如

（适当的方式之一）

默认情况下需要JFrame.pack()，而不是setVisible(false) and then true的其他木偶，或DecorationsType更改JFrame

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import javax.swing.UIManager.LookAndFeelInfo;

public class TestInternalFrame {

    private JFrame frame = new JFrame("Test");

    public TestInternalFrame() {
        final JInternalFrame internal = new JInternalFrame("test");
        final JInternalFrame hidden = new JInternalFrame("test");
        hidden.setBounds(1000, 1000, 1, 1);
        hidden.setVisible(true);
        internal.setVisible(true);
        internal.setBounds(0, 0, 100, 100);
        JDesktopPane pane = new JDesktopPane();
        pane.add(internal);
        pane.add(hidden);
        pane.setPreferredSize(new Dimension(10000, 10000));
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(new JScrollPane(pane,
                JScrollPane.VERTICAL_SCROLLBAR_NEVER,
                JScrollPane.HORIZONTAL_SCROLLBAR_NEVER));
        DefaultComboBoxModel model = new DefaultComboBoxModel();
        UIManager.LookAndFeelInfo[] info = UIManager.getInstalledLookAndFeels();
        for (int i = 0; i < info.length; i++) {
            model.addElement(info[i].getName());
        }
        final JComboBox box = new JComboBox(model);
        box.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                        if (box.getSelectedItem().equals(info.getName())) {
                            UIManager.setLookAndFeel(info.getClassName());
                            UIManager.getLookAndFeel().uninitialize();
                            UIManager.setLookAndFeel(info.getClassName());
                            SwingUtilities.updateComponentTreeUI(frame);
                            break;
                        }
                    }
                } catch (ClassNotFoundException ex) {
                    Logger.getLogger(TestInternalFrame.class.getName()).log(Level.SEVERE, null, ex);
                } catch (InstantiationException ex) {
                    Logger.getLogger(TestInternalFrame.class.getName()).log(Level.SEVERE, null, ex);
                } catch (IllegalAccessException ex) {
                    Logger.getLogger(TestInternalFrame.class.getName()).log(Level.SEVERE, null, ex);
                } catch (UnsupportedLookAndFeelException ex) {
                    Logger.getLogger(TestInternalFrame.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        });
        frame.add(box, BorderLayout.NORTH);
        frame.setPreferredSize(new Dimension(400, 300));
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                TestInternalFrame tif = new TestInternalFrame();
            }
        });
    }
}