考虑下面过于简化的例子;其中一些用伪代码编写，以简洁起见。当我尝试按原样运行时，我收到编译器错误，指出actionPerformed方法中已找到main。但是，如果我重命名它，请说actionPerformed2 ActionListener不再识别它。
我是否需要将foo和foo2方法的侦听器合并为一个ActionListener方法？在具有多个按钮对象的单个类中使用多个侦听器时，如何正确区分侦听器？
我刚刚开始使用摇摆组件，所以我怀疑我可能不会问正确的问题......但是我可以随时编辑。 :)
public class foo {
declare button1, button2, button3 and panel1
public foo() {
show panel1 with button1 and button2;
}
public foo2() {
show panel1 with button3;
}
public void actionPerformed(ActionEvent e) {
Object source1 = e.getSource();
do some stuff when button1 is clicked
}
public void actionPerformed(ActionEvent f) {
Object source2 = f.getSource();
do some other stuff when button2 is clicked
}
public static void main(String[] args) {
foo myFoo = new foo();
}
}
答案 0 :(得分：10)
为此使用匿名内部类。
例如，您永远不会写但代表点的代码：
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class Foo extends JPanel {
private JButton btnA = new JButton("Button A");
private JButton btnB = new JButton("Button B");
private JButton btnC = new JButton("Button C");
public Foo() {
btnA.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
System.out.println("button A Action");
}
});
btnB.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
System.out.println("button B Action");
}
});
btnC.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
System.out.println("button C Action");
}
});
add(btnA);
add(btnB);
add(btnC);
}
private static void createAndShowGui() {
Foo mainPanel = new Foo();
JFrame frame = new JFrame("Foo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
我自己，我正在使用更多的AbstractActions和更少的ActionListeners，甚至开始使用Command Design Pattern与PropertyChangeListener一起使用。
例如，我最新的GUI“视图”部分如下所示：
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.beans.PropertyChangeListener;
import java.util.HashMap;
import java.util.Map;
import javax.swing.*;
import javax.swing.event.SwingPropertyChangeSupport;
@SuppressWarnings("serial")
public class View {
enum TextAreaDestination {
EGD_IMPRESSION("EGD Impression"),
EGD_RECOMMENDATIONS("EGD Recommendations"),
COLON_IMPRESSION("Colon Impression"),
COLON_RECOMMENDATIONS("Colon Recommendations"),
ERROR_MESSAGES("Error Messages");
private String text;
private TextAreaDestination(String text) {
this.text = text;
}
public String getText() {
return text;
}
@Override
public String toString() {
return text;
}
}
public enum GuiButtonText {
GET_ONE_PROC("Get One Proc", KeyEvent.VK_O),
GET_TWO_PROCs("Get Two Procs", KeyEvent.VK_T),
INTO_FLOW("Into Flow", KeyEvent.VK_F),
CLEAR_ALL("Clear All", KeyEvent.VK_C),
F_U_PROC_FLAG("F/U Proc Flag", KeyEvent.VK_U),
SIGN_NEXT("Sign/Next", KeyEvent.VK_S),
EXIT("Exit", KeyEvent.VK_X);
private String text;
private int mnemonic;
private GuiButtonText(String text, int mnemonic) {
this.text = text;
this.mnemonic = mnemonic;
}
public String getText() {
return text;
}
public int getMnemonic() {
return mnemonic;
}
}
public static final String BUTTON_PRESSED = "Button Pressed";
private static final int TA_ROWS = 4;
private static final int TA_COLS = 50;
private JPanel mainPanel = new JPanel();
private SwingPropertyChangeSupport spcSupport = new SwingPropertyChangeSupport(
this);
private Map<TextAreaDestination, JTextArea> impressionRecMap = new HashMap<TextAreaDestination, JTextArea>();
public View() {
JPanel textAreasPanel = createTextAreasPanel();
JPanel buttonsPanel = createButtonsPanel();
mainPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
mainPanel.setLayout(new BorderLayout(5, 5));
mainPanel.add(textAreasPanel, BorderLayout.CENTER);
mainPanel.add(buttonsPanel, BorderLayout.PAGE_END);
}
private JPanel createButtonsPanel() {
JPanel buttonsPanel = new JPanel(new GridLayout(2, 0, 5, 5));
for (final GuiButtonText guiBtnText : GuiButtonText.values()) {
AbstractAction btnAction = new AbstractAction(guiBtnText.getText()) {
{putValue(MNEMONIC_KEY, guiBtnText.getMnemonic()); }
@Override
public void actionPerformed(ActionEvent e) {
spcSupport.firePropertyChange(BUTTON_PRESSED, null, guiBtnText);
}
};
JButton button = new JButton(btnAction);
buttonsPanel.add(button);
}
return buttonsPanel;
}
private JPanel createTextAreasPanel() {
JPanel textAreasPanel = new JPanel();
textAreasPanel.setLayout(new BoxLayout(textAreasPanel,
BoxLayout.PAGE_AXIS));
for (TextAreaDestination textDest : TextAreaDestination.values()) {
JTextArea tArea = new JTextArea(TA_ROWS, TA_COLS);
tArea.setName(textDest.getText());
tArea.setWrapStyleWord(true);
tArea.setLineWrap(true);
impressionRecMap.put(textDest, tArea);
JScrollPane scrollPane = new JScrollPane(tArea);
JPanel outerPanel = new JPanel(new BorderLayout());
outerPanel.setBorder(BorderFactory.createTitledBorder(textDest.getText()));
outerPanel.add(scrollPane);
textAreasPanel.add(outerPanel);
}
return textAreasPanel;
}
public String textAreasGetText(TextAreaDestination key) {
JTextArea textArea = impressionRecMap.get(key);
if (textArea != null) {
return textArea.getText();
} else {
return ""; // throw exception
}
}
public void textAreasSetText(TextAreaDestination key, String text) {
JTextArea textArea = impressionRecMap.get(key);
if (textArea != null) {
textArea.setText(text);
} else {
// throw exception?
}
}
public void textAreaAppend(TextAreaDestination key, String text) {
JTextArea textArea = impressionRecMap.get(key);
textArea.append(text);
}
public void clearAllAreas() {
for (TextAreaDestination taDest : TextAreaDestination.values()) {
textAreasSetText(taDest, "");
}
}
public void addPropertyChangeListener(PropertyChangeListener listener) {
spcSupport.addPropertyChangeListener(listener);
}
public void removePropertyChangeListener(PropertyChangeListener listener) {
spcSupport.removePropertyChangeListener(listener);
}
public JPanel getMainPanel() {
return mainPanel;
}
public static void main(String[] args) {
Control.main(args);
}
}
“控制”部分的一部分看起来像这样：
import java.awt.Component;
import java.awt.Window;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import javax.swing.*;
import procedure.findings4.View.TextAreaDestination;
public class Control {
public static final boolean DEBUG = false;
public static final String CENTRICITY_WINDOW_NAME = "Centricity EMR";
private DriverModel driverModel = null;
private View view;
private Map<View.GuiButtonText, Runnable> runnableMap = new HashMap<View.GuiButtonText, Runnable>();
public Control() {
runnableMap.put(View.GuiButtonText.GET_ONE_PROC, new GetOneProcRunnable());
runnableMap.put(View.GuiButtonText.GET_TWO_PROCs,
new GetTwoProcsRunnable());
runnableMap.put(View.GuiButtonText.INTO_FLOW, new IntoFlowRunnable());
runnableMap.put(View.GuiButtonText.CLEAR_ALL, new ClearAllRunnable());
runnableMap.put(View.GuiButtonText.SIGN_NEXT, new SignNextRunnable());
runnableMap.put(View.GuiButtonText.EXIT, new ExitRunnable());
}
public void setView(View view) {
this.view = view;
view.addPropertyChangeListener(new ViewChangeListener());
}
//....
private class ViewChangeListener implements PropertyChangeListener {
@Override
public void propertyChange(PropertyChangeEvent pcEvt) {
if (pcEvt.getPropertyName().equals(View.BUTTON_PRESSED)) {
Runnable run = runnableMap.get(pcEvt.getNewValue());
if (run != null) {
run.run();
}
}
}
}
//....
请注意，我并不是自称是专家，但我只是尽力管理复杂性。可能有更好的方法来抚育这只猫。