import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.SwingConstants; import javax.swing.UIManager; public class ButtonArrayExample extends JFrame { // 继承窗体类JFrame     /**      *      */     private static final long serialVersionUID = 6626440733001287873L;     private JTextField textField;     public static void main(String args[]) {         try {             UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");         } catch (Throwable e) {             e.printStackTrace();         }         ButtonArrayExample frame = new ButtonArrayExample();         frame.setVisible(true); // 设置窗体可见，默认为不可见     }     public ButtonArrayExample() {         super(); // 继承父类的构造方法         BorderLayout borderLayout = (BorderLayout) getContentPane().getLayout();         borderLayout.setHgap(20);         borderLayout.setVgap(10);         setTitle("按钮数组实现计算器界面 "); // 设置窗体的标题         setBounds(100, 100, 290, 282); // 设置窗体的显示位置及大小         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭按钮的动作为退出         textField = new JTextField();         textField.setHorizontalAlignment(SwingConstants.TRAILING);         textField.setPreferredSize(new Dimension(12, 50));         getContentPane().add(textField, BorderLayout.NORTH);         textField.setColumns(10);         final GridLayout gridLayout = new GridLayout(4, 0); // 创建网格布局管理器对象         gridLayout.setHgap(5); // 设置组件的水平间距         gridLayout.setVgap(5); // 设置组件的垂直间距         JPanel panel = new JPanel(); // 获得容器对象         panel.setLayout(gridLayout); // 设置容器采用网格布局管理器         getContentPane().add(panel, BorderLayout.CENTER);         String[][] names = { { "1", "2", "3", "＋" }, { "4", "5", "6", "－" }, { "7", "8", "9", "×" }, { ".", "0", "=", "÷" } };         JButton[][] buttons = new JButton[4][4];         for (int row = 0; row < names.length; row++) {             for (int col = 0; col < names.length; col++) {                 buttons[row][col] = new JButton(names[row][col]); // 创建按钮对象                 buttons[row][col].addActionListener(new ActionListener() {                     @Override                     public void actionPerformed(ActionEvent e) {                         JButton button = (JButton) e.getSource();                         String text = textField.getText();                         textField.setText(text + button.getText());                     }                 });                 panel.add(buttons[row][col]); // 将按钮添加到面板中             }         }     } }