Questo semplice programma non mi funziona ( ho provato su due PC con ubuntu jaunty 9.04 ), su Windows invece si.<br><br>import java.awt.*;<br>import java.awt.event.*;<br>import javax.swing.*;<br>import java.awt.peer.*; <br>
<br>public class ButtonTest {<br><br> public static void main (String[] args){<br> <br> ButtonFrame frame = new ButtonFrame();<br> frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);<br> frame.setVisible(true); <br>
}<br> <br>}<br><br>class ButtonFrame extends JFrame {<br><br> /**<br> * <br> */<br> private static final long serialVersionUID = 1L;<br> public ButtonFrame(){<br> <br> setTitle("Button Test");<br>
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);<br> <br> Container contentPane = getContentPane();<br> ButtonPanel panel = new ButtonPanel();<br> contentPane.add(panel);<br> }<br> <br> public static final int DEFAULT_WIDTH=300;<br>
public static final int DEFAULT_HEIGHT=200;<br>}<br><br>class ButtonPanel extends JPanel <br> {<br><br> /**<br> * <br> */<br> private static final long serialVersionUID = 1L;<br> JButton yellowButton = new JButton("Yellowq");<br>
JButton redButton = new JButton("Red");<br> JButton greenButton = new JButton("Green");<br> <br> public ButtonPanel() {<br><br> add(yellowButton);<br> add(redButton);<br> add(greenButton);<br>
<br> yellowButton.addActionListener(new ActionListener(){<br> public void actionPerformed(ActionEvent event){<br> setBackground(Color.YELLOW); <br> }<br> });<br> <br>
redButton.addActionListener(new ActionListener(){<br> public void actionPerformed(ActionEvent event){<br> setBackground(Color.RED);<br> }<br> });<br> <br> greenButton.addActionListener(new ActionListener(){<br>
public void actionPerformed(ActionEvent event){<br> setBackground(Color.GREEN);<br> }<br> });<br> <br> }<br><br>}<br>