Java JButton并未真正运行

Question

我添加了一个带有eclipse的jbutton，但是它没有正确显示。 我如何解决它？

这是屏幕截图 ：

public class GUITest // test class
{
    // block the warnings
    public static void main(String[] args) //main
    {
        System.out.println("start of main");
        /* stackoverflow want to add more details */
        JFrame frame = new JFrame();
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300,300);
        JPanel panel = new JPanel();
        frame.add(panel);
        JButton button = new JButton("Click here");
        panel.add(button);
        button.addActionListener(new Action());
        System.out.println("end of main");

/ * stackoverflow要添加更多详细信息* /}

    public static class Action implements ActionListener //actionlistener
    {
        public void actionPerformed (ActionEvent e)
        { /* stackoverflow want to add more details */
            JFrame frame2 = new JFrame("Clicked");
            frame2.setVisible(true);
            frame2.setSize(200,200);
            JLabel label = new JLabel("You clicked me!");
            JPanel panel = new JPanel();
            frame2.add(panel);
            panel.add(label); // some more details

        }
    }   
}

Answer 1

我已经用过了，它将正常工作。 能否请您检查图形驱动程序或其他内容。

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author Ashwin Parmar
 */
public class GUITest {
    public static void main(String[] args) {
        System.out.println("Start");
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 300);
        JPanel panel = new JPanel();
        frame.add(panel);
        JButton button = new JButton("Click here");
        panel.add(button);
        button.addActionListener(new Action());
        frame.setVisible(true);
        System.out.println("End");
    }

    public static class Action implements ActionListener{

        @Override
        public void actionPerformed(ActionEvent ae) {
            //throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
            JFrame frame2 = new JFrame("Clicked");
            frame2.setSize(200,200);
            JLabel label = new JLabel("You have clicked me!");
            JPanel panel = new JPanel();
            frame2.add(panel);
            panel.add(label);
            frame2.setVisible(true);
        }

    }

}

Answer 2

• 始终在事件调度线程的上下文中创建和修改UI
• 建立基本UI后，请尽可能最后调用setVisible 。 如果在窗口可见后添加组件，则需要调用revalidate和repaint 。

例如...

public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        @Override
        public void run() {
            try {
                UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
            } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                ex.printStackTrace();
            }

            JFrame frame = new JFrame("Testing");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            JPanel panel = new JPanel();
            frame.add(panel);
            JButton button = new JButton("Click here");
            panel.add(button);
            button.addActionListener(new Action());             
            frame.pack();
            frame.setLocationRelativeTo(null);
            frame.setVisible(true);
        }
    });
}

在ActionListener执行相同的操作。

有关更多详细信息，请参见初始线程 。