java - 如何在 Java 中将 ActionListener 添加到框架中的按钮

Question

我正在尝试测试按钮，但我无法让 Action Listener 工作

public class ButtonTester implements ActionListener {

static JLabel Label = new JLabel("Hello Buttons! Will You Work?!");
public static void main(String[] args) {
    //Creating a Label for step 3
    // now for buttons
    JButton Button1 = new JButton("Test if Button Worked");
    // step 1: create the frame
    JFrame frame = new JFrame ("FrameDemo");
    //step 2: set frame behaviors (close buttons and stuff)
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    //step 3: create labels to put in the frame
    frame.getContentPane().add(Label, BorderLayout.NORTH);
    frame.getContentPane().add(Button1, BorderLayout.AFTER_LAST_LINE);
    //step 4: Size the frame
    frame.pack();
    //step 5: show the frame 
    frame.setVisible(true);
    Button1.setActionCommand("Test");
    Button1.setEnabled(true);
    Button1.addActionListener(this); //this line here won't work
}
@Override
public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub
    if("Test".equals(e.getActionCommand()))
    {
        Label.setText("It Worked!!!");
    }
  }

}

Answer 1

静态方法不与类的实例相关联，因此不能使用 this。

您可以将所有代码从 main 移动到 ButtonTester 的非静态方法(例如，run())并从 main 执行类似这样的操作:

new ButtonTester().run();

您还可以为 ActionListener 使用匿名内部类:

Button1.addActionLister(new ActionListener() {
    @Override public void actionPerformed (ActionEvent e) {
        // ... 
    }
});