Question

所以当我点击按钮时，我正试图让ActionListener工作。每当我创建一个框架时（错误似乎发生在createComponents（）方法中，我看不出原因）JVM一直在生成MyCustomFrame对象的无限实例。

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class MyCustomFrame extends JFrame
{
private JButton button;
private JLabel label;
private static final int FRAME_WIDTH = 800;
private static final int FRAME_HEIGHT = 800;

public static void main(String[] args)
{
    MyCustomFrame frame = new MyCustomFrame();
    frame.setTitle("My first frame");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
}

public MyCustomFrame()
{
    setTitle("My Custom Frame");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(FRAME_WIDTH,FRAME_HEIGHT);
    setVisible(true);
    createComponents();
}

private void createComponents()
{
    button = new JButton("Click me!");
    ClickListener listener = new ClickListener();
    button.addActionListener(listener);
    label = new JLabel("Hello, World!");
    JPanel panel = new JPanel();
    panel.add(button);
    panel.add(label);
    add(panel);
}

class ClickListener extends MyCustomFrame implements ActionListener
{
    public void actionPerformed(ActionEvent e)
    {
        label.setText("Button was clicked.");
    }

}

}

Answer 1

class ClickListener extends MyCustomFrame implements ActionListener

MouseListener没有理由扩展Frame。每次创建监听器时都会显示另一个框架，这会创建另一个监听器，依此类推。

代码应该是：

class ClickListener implements ActionListener

Answer 2

我认为你应该这样做

button.addActionListener(this)

然后在类似

的同一个类中创建一个方法

public void actionPerformed(ActionEvent e) {
    label.setText("Button was clicked.");
}

至少这对我有用

ActionListener Unorthodox Infinate Frame Java

2 个答案: