将单个动作侦听器附加到所有按钮

就像是：

import java.awt.*;import java.awt.event.*;import javax.swing.*;import javax.swing.border.*;public class CalculatorPanel extends JPanel{    private JTextField display;    public CalculatorPanel()    {        Action numberAction = new AbstractAction()        { @Override public void actionPerformed(ActionEvent e) {     display.setCaretPosition( display.getdocument().getLength() );     display.replaceSelection(e.getActionCommand()); }        };        setLayout( new BorderLayout() );        display = new JTextField();        display.setEditable( false );        display.setHorizontalAlignment(JTextField.RIGHT);        add(display, BorderLayout.NORTH);        JPanel buttonPanel = new JPanel();        buttonPanel.setLayout( new GridLayout(0, 5) );        add(buttonPanel, BorderLayout.CENTER);        for (int i = 0; i < 10; i++)        { String text = String.valueOf(i); JButton button = new JButton( text ); button.addActionListener( numberAction ); button.setBorder( new LineBorder(Color.BLACK) ); button.setPreferredSize( new Dimension(50, 50) ); buttonPanel.add( button ); KeyStroke pressed = KeyStroke.getKeyStroke(text); InputMap inputMap = button.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW); inputMap.put(pressed, text); button.getActionMap().put(text, numberAction);        }    }    private static void createAndShowUI()    {//      UIManager.put("Button.margin", new Insets(10, 10, 10, 10) );        Jframe frame = new Jframe("Calculator Panel");        frame.setDefaultCloseOperation( Jframe.EXIT_ON_CLOSE );        frame.add( new CalculatorPanel() );        frame.pack();        frame.setLocationRelativeTo( null );        frame.setVisible(true);    }    public static void main(String[] args)    {        EventQueue.invokeLater(new Runnable()        { public void run() {     createAndShowUI(); }        });    }}

该

Action

如果您需要在Action中使用if / else逻辑，那么您应该创建一个单独的Action。如果代码不属于某个动作，请勿将其强制执行。