Question

我正在编写一个应用程序来点击jbutton来选择随机数。但是当我运行应用程序时，我得到了这个例外：

线程中的异常＆＃34; main＆＃34; java.lang.IllegalArgumentException：向容器添加窗口在java.awt.Container.checkNotAWindow（Container.java:483）在java.awt.Container.addImpl（Container.java:1084）在java.awt.Container.add（Container.java:410）在Final.main（Final.java:37）

这是我的代码：

import java.util.ArrayList;
import java.awt.*;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


public class Final extends JPanel {

    public static void main(String[] args) {

        // Random numbers that i have selected
        ArrayList numbers = new ArrayList();
        numbers.add(40);
        numbers.add(500);
        numbers.add(90);
        numbers.add(10);
        numbers.add(50);
        numbers.add(25);

        // The panel for the GUI
        JPanel panel = new JPanel();
        // And of course the frame and its characteristics
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setTitle("Random Numbers!");
        frame.setVisible(true);
        frame.setSize(300,150);


        // The button for selecting a random number from the arraylist
        JButton button = new JButton();
        button.setText("Click me!");

        // Finally add the objects to the panel
        frame.add(button);
        panel.add(frame);        
    } 
}

Answer 1

而不是：

    // Finally add the objects to the panel
    frame.add(button);
    panel.add(frame);

尝试类似：

    // Finally add the objects to the panel
    frame.add(button, BorderLayout.PAGE_START); // top of the frame
    frame.add(panel); // defaults to CENTER

线程“main”中的异常将窗口添加到容器中

1 个答案: