Question

我添加了一个带有eclipse的jbutton，但它没有正确看到。我该如何解决？

this is screen shot： enter image description here

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想要添加更多细节* / }

    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

我已经使用了它，它会正常工作。你可以检查你的图形驱动程序或其他东西。

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Event Dispatching Thread
在建立基本用户界面后，尽可能最后拨打setVisible。如果您在窗口可见后添加组件，则需要致电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中执行相同的操作。

有关详细信息，请参阅Initial Threads

Java JButton它没有真正运行

2 个答案: