Question

java使用三个外观 我写后显示不出来 这是什么情况？麻烦帮我看一下什么问题？

meta = new JRadioButtonMenuItem("Meta风格", true);
motif = new JRadioButtonMenuItem("Motif风格");
windows = new JRadioButtonMenuItem("Windows风格");

meta.addActionListener(new MetaListener());
motif.addActionListener(new MotifListener());
windows.addActionListener(new WindowsListener());

public class MetaListener implements ActionListener{

public void actionPerformed(ActionEvent arg0) {
try {// 设置窗体外观
UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
} catch (Throwable e) {
e.printStackTrace();
}
}

}

Answer 1

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Vector;
import javax.swing.BoxLayout;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.LookAndFeel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class LittleWhite extends JFrame implements ActionListener
{
	private static final long serialVersionUID = 1L;
	private static final String PLASTIC3D = "com.jgoodies.looks.plastic.Plastic3DLookAndFeel";
	private static final String PLASTIC = "com.jgoodies.looks.plastic.PlasticLookAndFeel";
	private static final String PLASTXP = "com.jgoodies.looks.plastic.PlasticXPLookAndFeel";
	private Vector<SupportedLaF> lafVector = new Vector<SupportedLaF> ();

	public LittleWhite ()
	{
		UIManager.installLookAndFeel ("Plastic3D", PLASTIC3D);
		UIManager.installLookAndFeel ("Plastic", PLASTIC);
		UIManager.installLookAndFeel ("PlasticXP", PLASTXP);
		UIManager.LookAndFeelInfo[] installedLafs = UIManager.getInstalledLookAndFeels ();
		for ( UIManager.LookAndFeelInfo lafInfo : installedLafs )
		{
			try
			{
				Class<?> lnfClass = Class.forName (lafInfo.getClassName ());
				LookAndFeel laf = (LookAndFeel) ( lnfClass.newInstance () );
				if (laf.isSupportedLookAndFeel ())
				{
					String name = lafInfo.getName ();
					lafVector.add (new SupportedLaF (name, laf));
				}
			}
			catch (Exception e)
			{
				continue;
			}
		}
	}

	private class SupportedLaF
	{
		String name;
		LookAndFeel laf;

		SupportedLaF ( String name, LookAndFeel laf )
		{
			this.name = name;
			this.laf = laf;
		}

		public String toString ()
		{
			return name;
		}
	}

	private void addComponents ()
	{
		JPanel panel = new JPanel ();
		panel.setLayout (new BoxLayout (panel, BoxLayout.Y_AXIS));
		ButtonGroup bg = new ButtonGroup ();
		for ( int i = 0; i < lafVector.size (); i++ )
		{
			JRadioButton r = new JRadioButton (lafVector.get (i).toString ());
			r.setName (i + "");
			r.addActionListener (this);
			bg.add (r);
			panel.add (r);
		}
		add (panel);
	}

	public static void main ( String[] args )
	{
		LittleWhite littleWhite = new LittleWhite ();
		littleWhite.setTitle ("LittleWhite");
		littleWhite.setSize (400, 300);
		littleWhite.setLocationRelativeTo (null);
		littleWhite.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
		littleWhite.setLayout (new FlowLayout (FlowLayout.LEFT));
		littleWhite.addComponents ();
		littleWhite.setVisible (true);
	}

	@Override
	public void actionPerformed ( ActionEvent e )
	{
		JRadioButton target = (JRadioButton) e.getSource ();
		try
		{
			UIManager.setLookAndFeel (lafVector.get (Integer.parseInt (target.getName ())).laf);
			SwingUtilities.updateComponentTreeUI (this);
		}
		catch (UnsupportedLookAndFeelException exc)
		{
			System.err.println (exc.toString ());
		}
	}
}