如何从不同的类定义多个JButton动作

我正在编写一个程序，我需要根据单击哪个button，为单独的类执行不同的操作。

public class NewJFrame{ public static JButton b1; public static JButton b2; public static JButton b3; } public class Slot{ int value; JButton button; Slot(int value, JButton button) { this.value=value; this.button=button; } } public class Game{ Slot[] slots=new Slot[3]; Game(){ slots[0]=new Slot(1,NewJFrame.b1); slots[1]=new Slot(2,NewJFrame.b2); slots[2]=new Slot(3,NewJFrame.b3); } public void actionPerformed(ActionEvent e) { for(int i=0;i<3;i++){ if(e.getSource()==slots[i].button) slots[i].button.setText(String.valueOf(value)); } } } 

像这样的东西。 请注意，我是GUIdevise的新手。

Answer 1

使用Action来封装程序中其他地方使用的function，例如button，菜单和工具栏。 下面显示的BeaconPanel导出了几个操作，可以方便地在控制面板中使用它们。 为了限制事例的扩散，行为本身可以是类成员。 作为练习，将controls更改为JToolBar或将相同的操作添加到菜单。

 JPanel controls = new JPanel(); controls.add(new JButton(beaconPanel.getFlashAction())); controls.add(new JButton(beaconPanel.getOnAction())); controls.add(new JButton(beaconPanel.getOffAction())); 

 import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.geom.Ellipse2D; import javax.swing.AbstractAction; import javax.swing.Action; import javax.swing.Timer; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; /** @see http://stackoverflow.com/a/37063037/230513 */ public class Beacon { private static class BeaconPanel extends JPanel { private static final int N = 16; private final Ellipse2D.Double ball = new Ellipse2D.Double(); private final Timer timer; private final Color on; private final Color off; private final AbstractAction flashAction = new AbstractAction("Flash") { @Override public void actionPerformed(ActionEvent e) { timer.restart(); } }; private final AbstractAction onAction = new AbstractAction("On") { @Override public void actionPerformed(ActionEvent e) { stop(on); } }; private final AbstractAction offAction = new AbstractAction("Off") { @Override public void actionPerformed(ActionEvent e) { stop(off); } }; private Color currentColor; public BeaconPanel(Color on, Color off) { this.on = on; this.off = off; this.currentColor = on; timer = new Timer(500, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { changeColors(); } }); } public void start() { timer.start(); } @Override public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D) g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); int x = getX() + N; int y = getY() + N; int w = getWidth() - 2 * N; int h = getHeight() - 2 * N; ball.setFrame(x, y, w, h); g2.setColor(currentColor); g2.fill(ball); g2.setColor(Color.black); g2.draw(ball); } private void changeColors() { currentColor = currentColor == on ? off : on; repaint(); } private void stop(Color color) { timer.stop(); currentColor = color; repaint(); } public Action getFlashAction() { return flashAction; } public Action getOnAction() { return onAction; } public Action getOffAction() { return offAction; } @Override public Dimension getPreferredSize() { return new Dimension(N * N, N * N); } } public static void display() { JFrame f = new JFrame("Beacon"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); final BeaconPanel beaconPanel = new BeaconPanel(Color.orange, Color.orange.darker()); f.add(beaconPanel); JPanel controls = new JPanel(); controls.add(new JButton(beaconPanel.getFlashAction())); controls.add(new JButton(beaconPanel.getOnAction())); controls.add(new JButton(beaconPanel.getOffAction())); f.add(controls, BorderLayout.SOUTH); f.pack(); f.setLocationRelativeTo(null); f.setVisible(true); beaconPanel.start(); } public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { @Override public void run() { Beacon.display(); } }); } }