问题:写了个example学习Swing:每次Timer Event(once per sec)发生时选择下一个RadioButton。但总是选择下下一个。
平台:Mac OS X, JDK1.6, Eclipse3.6
调试:经过调试,发现每秒fire两个Timer Event。
代码:Timer相关内容用粗体字标识package components;import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.Timer;public class RadioButtonDemo extends JPanel
implements ActionListener{ private static final long serialVersionUID = 1L;
static String birdString = "Bird";
static String catString = "Cat";
static String dogString = "Dog";
static String rabbitString = "Rabbit";
static String pigString = "Pig";
JButton autoButton;
JRadioButton birdButton, catButton, dogButton, rabbitButton, pigButton;
Timer timer = new Timer(1000,this);
public RadioButtonDemo() {
super(new BorderLayout());
//Create the AUTO button.
autoButton = new JButton("auto");
autoButton.setActionCommand("auto");
//Create the radio buttons.
birdButton = new JRadioButton(birdString);
birdButton.setMnemonic(KeyEvent.VK_B);
birdButton.setActionCommand(birdString);
birdButton.setSelected(true); catButton = new JRadioButton(catString);
catButton.setMnemonic(KeyEvent.VK_C);
catButton.setActionCommand(catString); dogButton = new JRadioButton(dogString);
dogButton.setMnemonic(KeyEvent.VK_D);
dogButton.setActionCommand(dogString); rabbitButton = new JRadioButton(rabbitString);
rabbitButton.setMnemonic(KeyEvent.VK_R);
rabbitButton.setActionCommand(rabbitString); pigButton = new JRadioButton(pigString);
pigButton.setMnemonic(KeyEvent.VK_P);
pigButton.setActionCommand(pigString); //Group the radio buttons.
ButtonGroup group = new ButtonGroup();
group.add(birdButton);
group.add(catButton);
group.add(dogButton);
group.add(rabbitButton);
group.add(pigButton);
//Register a listener for the radio buttons.
birdButton.addActionListener(this);
catButton.addActionListener(this);
dogButton.addActionListener(this);
rabbitButton.addActionListener(this);
pigButton.addActionListener(this);
autoButton.addActionListener(this); //Put the radio buttons in a column in a panel.
JPanel radioPanel = new JPanel(new GridLayout(0, 1));
radioPanel.add(birdButton);
radioPanel.add(catButton);
radioPanel.add(dogButton);
radioPanel.add(rabbitButton);
radioPanel.add(pigButton); add(radioPanel, BorderLayout.LINE_START);
add(autoButton,BorderLayout.CENTER);
setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
} /** Listens to the radio buttons. */
public void actionPerformed(ActionEvent e) {
if ("timer".equals(e.getActionCommand())) {
if(birdButton.isSelected()){
catButton.setSelected(true);
}
else if(catButton.isSelected()){
dogButton.setSelected(true);
}
else if(dogButton.isSelected()){
rabbitButton.setSelected(true);
}
else if(rabbitButton.isSelected()){
pigButton.setSelected(true);
}
else if(pigButton.isSelected()){
birdButton.setSelected(true);
}
}
else if("auto".equals(e.getActionCommand())){
timer.addActionListener(this);
timer.setActionCommand("timer");
timer.setInitialDelay(1000);
timer.start();
}
} /**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("RadioButtonDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane.
JComponent newContentPane = new RadioButtonDemo();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setVisible(true);
} public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}请给个思路fix这个问题。
谢谢您的时间
平台:Mac OS X, JDK1.6, Eclipse3.6
调试:经过调试,发现每秒fire两个Timer Event。
代码:Timer相关内容用粗体字标识package components;import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.Timer;public class RadioButtonDemo extends JPanel
implements ActionListener{ private static final long serialVersionUID = 1L;
static String birdString = "Bird";
static String catString = "Cat";
static String dogString = "Dog";
static String rabbitString = "Rabbit";
static String pigString = "Pig";
JButton autoButton;
JRadioButton birdButton, catButton, dogButton, rabbitButton, pigButton;
Timer timer = new Timer(1000,this);
public RadioButtonDemo() {
super(new BorderLayout());
//Create the AUTO button.
autoButton = new JButton("auto");
autoButton.setActionCommand("auto");
//Create the radio buttons.
birdButton = new JRadioButton(birdString);
birdButton.setMnemonic(KeyEvent.VK_B);
birdButton.setActionCommand(birdString);
birdButton.setSelected(true); catButton = new JRadioButton(catString);
catButton.setMnemonic(KeyEvent.VK_C);
catButton.setActionCommand(catString); dogButton = new JRadioButton(dogString);
dogButton.setMnemonic(KeyEvent.VK_D);
dogButton.setActionCommand(dogString); rabbitButton = new JRadioButton(rabbitString);
rabbitButton.setMnemonic(KeyEvent.VK_R);
rabbitButton.setActionCommand(rabbitString); pigButton = new JRadioButton(pigString);
pigButton.setMnemonic(KeyEvent.VK_P);
pigButton.setActionCommand(pigString); //Group the radio buttons.
ButtonGroup group = new ButtonGroup();
group.add(birdButton);
group.add(catButton);
group.add(dogButton);
group.add(rabbitButton);
group.add(pigButton);
//Register a listener for the radio buttons.
birdButton.addActionListener(this);
catButton.addActionListener(this);
dogButton.addActionListener(this);
rabbitButton.addActionListener(this);
pigButton.addActionListener(this);
autoButton.addActionListener(this); //Put the radio buttons in a column in a panel.
JPanel radioPanel = new JPanel(new GridLayout(0, 1));
radioPanel.add(birdButton);
radioPanel.add(catButton);
radioPanel.add(dogButton);
radioPanel.add(rabbitButton);
radioPanel.add(pigButton); add(radioPanel, BorderLayout.LINE_START);
add(autoButton,BorderLayout.CENTER);
setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
} /** Listens to the radio buttons. */
public void actionPerformed(ActionEvent e) {
if ("timer".equals(e.getActionCommand())) {
if(birdButton.isSelected()){
catButton.setSelected(true);
}
else if(catButton.isSelected()){
dogButton.setSelected(true);
}
else if(dogButton.isSelected()){
rabbitButton.setSelected(true);
}
else if(rabbitButton.isSelected()){
pigButton.setSelected(true);
}
else if(pigButton.isSelected()){
birdButton.setSelected(true);
}
}
else if("auto".equals(e.getActionCommand())){
timer.addActionListener(this);
timer.setActionCommand("timer");
timer.setInitialDelay(1000);
timer.start();
}
} /**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("RadioButtonDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane.
JComponent newContentPane = new RadioButtonDemo();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setVisible(true);
} public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}请给个思路fix这个问题。
谢谢您的时间
package components;import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.Timer;public class RadioButtonDemo extends JPanel
implements ActionListener{ private static final long serialVersionUID = 1L;
static String birdString = "Bird";
static String catString = "Cat";
static String dogString = "Dog";
static String rabbitString = "Rabbit";
static String pigString = "Pig";
JButton autoButton;
JRadioButton birdButton, catButton, dogButton, rabbitButton, pigButton;
Timer timer = new Timer(1000,this);
public RadioButtonDemo() {
super(new BorderLayout());
//Create the AUTO button.
autoButton = new JButton("auto");
autoButton.setActionCommand("auto");
//Create the radio buttons.
birdButton = new JRadioButton(birdString);
birdButton.setMnemonic(KeyEvent.VK_B);
birdButton.setActionCommand(birdString);
birdButton.setSelected(true); catButton = new JRadioButton(catString);
catButton.setMnemonic(KeyEvent.VK_C);
catButton.setActionCommand(catString); dogButton = new JRadioButton(dogString);
dogButton.setMnemonic(KeyEvent.VK_D);
dogButton.setActionCommand(dogString); rabbitButton = new JRadioButton(rabbitString);
rabbitButton.setMnemonic(KeyEvent.VK_R);
rabbitButton.setActionCommand(rabbitString); pigButton = new JRadioButton(pigString);
pigButton.setMnemonic(KeyEvent.VK_P);
pigButton.setActionCommand(pigString); //Group the radio buttons.
ButtonGroup group = new ButtonGroup();
group.add(birdButton);
group.add(catButton);
group.add(dogButton);
group.add(rabbitButton);
group.add(pigButton);
//Register a listener for the radio buttons.
birdButton.addActionListener(this);
catButton.addActionListener(this);
dogButton.addActionListener(this);
rabbitButton.addActionListener(this);
pigButton.addActionListener(this);
autoButton.addActionListener(this); //Put the radio buttons in a column in a panel.
JPanel radioPanel = new JPanel(new GridLayout(0, 1));
radioPanel.add(birdButton);
radioPanel.add(catButton);
radioPanel.add(dogButton);
radioPanel.add(rabbitButton);
radioPanel.add(pigButton); add(radioPanel, BorderLayout.LINE_START);
add(autoButton,BorderLayout.CENTER);
setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
} /** Listens to the radio buttons. */
public void actionPerformed(ActionEvent e) {
if ("timer".equals(e.getActionCommand())) {
if(birdButton.isSelected()){
catButton.setSelected(true);
}
else if(catButton.isSelected()){
dogButton.setSelected(true);
}
else if(dogButton.isSelected()){
rabbitButton.setSelected(true);
}
else if(rabbitButton.isSelected()){
pigButton.setSelected(true);
}
else if(pigButton.isSelected()){
birdButton.setSelected(true);
}
}
else if("auto".equals(e.getActionCommand())){
timer.addActionListener(this);
timer.setActionCommand("timer");
timer.setInitialDelay(1000);
timer.start();
}
} /**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("RadioButtonDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane.
JComponent newContentPane = new RadioButtonDemo();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setVisible(true);
} public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
else if("auto".equals(e.getActionCommand())){//timer.addActionListener(this);将这行去掉再试试。
timer.setActionCommand("timer");
timer.setInitialDelay(0);
timer.start();
}