有很多的方法來添加ActionListener，給定JComponent（支持它的使用）。我在代碼片段中添加了一些評論，以幫助更好地解釋它們，並在評論中提供一些鏈接供將來參考。
1）如果該類實現的ActionListener接口，即，類本身包含actionPerformed(...)方法，那麼可以做到這一點，以這種方式：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Skeleton implements ActionListener {
private JFrame frame;
private JPanel contentPane;
private JButton button;
private void displayGUI() {
frame = new JFrame("Skeleton");
/*
* EXIT_ON_CLOSE is same as putting System.exit(0),
* which in some sense, doesnot allows one's
* application to terminate graciously.
*/
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
contentPane = new JPanel();
button = new JButton("This is a button.");
/*
* This is one way of attaching an ActionListener
* to the JButton, but the main disadvantage of
* this approach is, it breaks encapsulation,
* as you can see the public method, actionPerformed(),
* is lying free to be accessed by any code outside
* the scope of the class
*/
button.addActionListener(this);
contentPane.add(button);
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
Runnable runnable = new Runnable() {
@Override
public void run() {
new Skeleton().displayGUI();
}
};
EventQueue.invokeLater(runnable);
}
@Override
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(frame, "BINGO!",
"Information: ", JOptionPane.INFORMATION_MESSAGE);
}
}
2.）如果一個沒有按不想創建不必要的class文件。然後此方法中，其使用，EventHandler可以使用：
import java.awt.*;
import java.awt.event.*;
import java.beans.EventHandler;
import javax.swing.*;
public class Example1 {
private JFrame frame;
private JPanel contentPane;
private JButton button;
private void displayGUI() {
frame = new JFrame("Skeleton");
/*
* EXIT_ON_CLOSE is same as putting System.exit(0),
* which in some sense, doesnot allows one's
* application to terminate graciously.
*/
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
contentPane = new JPanel();
button = new JButton("This is a button.");
/*
* This is another way of attaching
* an ActionListener to the JButton,
* the main advantage of this approach
* is, that one does not have to create
* a new class to handle events
* More info regarding the use of this
* approach, can be found on this link :
* http://docs.oracle.com/javase/tutorial/uiswing/events/generalrules.html
*/
button.addActionListener((ActionListener)
EventHandler.create(ActionListener.class
, Example1.this, "buttonAction", ""));
contentPane.add(button);
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
Runnable runnable = new Runnable() {
@Override
public void run() {
new Example1().displayGUI();
}
};
EventQueue.invokeLater(runnable);
}
public void buttonAction(ActionEvent e) {
JOptionPane.showMessageDialog(frame, "BINGO!",
"Information: ", JOptionPane.INFORMATION_MESSAGE);
}
}
3.）如果一個是關於Encapsulation概念更加關注，則這種方法是有益的：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Example2 {
private JFrame frame;
private JPanel contentPane;
private JButton button;
private ActionListener buttonActions =
new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
JOptionPane.showMessageDialog(frame, "BINGO!",
"Information: ", JOptionPane.INFORMATION_MESSAGE);
}
};
private void displayGUI() {
frame = new JFrame("Skeleton");
/*
* EXIT_ON_CLOSE is same as putting System.exit(0),
* which in some sense, doesnot allows one's
* application to terminate graciously.
*/
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
contentPane = new JPanel();
button = new JButton("This is a button.");
/*
* This is another way of attaching
* an ActionListener to the JButton,
* the main advantage of this approach
* is, it adheres to encapsulation.
*/
button.addActionListener(buttonActions);
contentPane.add(button);
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
Runnable runnable = new Runnable() {
@Override
public void run() {
new Example2().displayGUI();
}
};
EventQueue.invokeLater(runnable);
}
}
4 ）如果更傾向於創建匿名類，那麼可以使用此方法：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Example3 {
private JFrame frame;
private JPanel contentPane;
private JButton button;
private void displayGUI() {
frame = new JFrame("Skeleton");
/*
* EXIT_ON_CLOSE is same as putting System.exit(0),
* which in some sense, doesnot allows one's
* application to terminate graciously.
*/
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
contentPane = new JPanel();
button = new JButton("This is a button.");
/*
* This is the fourth way of attaching
* an ActionListener to the JButton,
* the main advantage of this approach
* is, it adheres to encapsulation, the
* public method remains hidden
* inside the Anonymous Class
* More info can be found on this link :
* http://docs.oracle.com/javase/tutorial/java/javaOO/anonymousclasses.html
* The main disadvantage of this approach is
* that it doesnot gives you the privilege
* of separation of concerns, which can
* be done using the fifth approach,
* which is MVC - Pattern (Model-View-Controller)
* and moreover, it creates a hell lot of classes, in
* your project, which can lead to extra overhead
*/
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
JOptionPane.showMessageDialog(frame, "BINGO!",
"Information: ", JOptionPane.INFORMATION_MESSAGE);
}
});
contentPane.add(button);
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
Runnable runnable = new Runnable() {
@Override
public void run() {
new Example3().displayGUI();
}
};
EventQueue.invokeLater(runnable);
}
}
編輯：
5。）該方法包括使用Action而不是ActionListener。這是要用於共享各種JComponent選自S相同的功能，從而導致代碼重用
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Example4 {
private JFrame frame;
private JPanel contentPane;
private JMenuItem showMenuItem;
private JButton button;
private Action myActions;
/*
* This approach is basically used, when
* one wants to share the same functionality
* of different JComponents among each other,
* without writing redundant codes for each
* one of those components. Here JMenuItem
* and JButton are both using the same
* functionality, to perform the same task.
* More info can be found on this link:
* http://docs.oracle.com/javase/tutorial/uiswing/misc/action.html
*/
private class MyActions extends AbstractAction {
public MyActions(String title, String desc) {
super(title);
putValue(SHORT_DESCRIPTION, desc);
}
@Override
public void actionPerformed(ActionEvent ae) {
JOptionPane.showMessageDialog(frame, "BINGO!",
"Information: ", JOptionPane.INFORMATION_MESSAGE);
}
}
private void displayGUI() {
frame = new JFrame("Skeleton");
/*
* EXIT_ON_CLOSE is same as putting System.exit(0),
* which in some sense, doesnot allows one's
* application to terminate graciously.
*/
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
contentPane = new JPanel();
button = new JButton("This is a button.");
myActions = new MyActions("Show", "A small description");
button.setAction(myActions);
contentPane.add(button);
frame.setJMenuBar(getJMenuBar());
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
private JMenuBar getJMenuBar() {
JMenuBar menuBar = new JMenuBar();
JMenu fileMenu = new JMenu("File");
showMenuItem = new JMenuItem(myActions);
fileMenu.add(showMenuItem);
menuBar.add(fileMenu);
return menuBar;
}
public static void main(String[] args) {
Runnable runnable = new Runnable() {
@Override
public void run() {
new Example4().displayGUI();
}
};
EventQueue.invokeLater(runnable);
}
}
'buttonName.addActionListener（this）;' – 2014-09-02 15:28:11