由于 java.lang.IllegalArgumentException，程序无法正常运行

Question

下面的程序不想运行，我也不知道为什么。

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

    public class Lab2Part4 extends JFrame {
        public Lab2Part4() {

        setTitle("My Pics");
        setSize(500, 500);
        setVisible(true);

        Icon carIcon = new ImageIcon("db10.jpg");

        JLabel carLabel = new JLabel("new Aston");
        carLabel.setIcon(carIcon);
        carLabel.setHorizontalAlignment(JLabel.RIGHT);

        JTextArea carTa = new JTextArea();
        carTa.setText("this is the new JB car");

        Container contentPane = getContentPane();
        JPanel labelPanel = new JPanel();
        JPanel textPanel = new JPanel();

        labelPanel.add(carLabel);
        textPanel.add(carTa);

        contentPane.add(labelPanel, textPanel);
    }

    public static void main(String[] args){
        Lab2Part4 myFrame = new Lab2Part4();
    }
}

现在它编译并且框架出现在屏幕上但是没有图像或标签并且命令提示符中的错误如下：

Exception in thread "main" java.lang.IllegalArgumentException: cannot add to layout: constraint must be a string (or null)
    at java.awt.BorderLayout.addLayoutComponent(BorderLayout.java:426)
    at javax.swing.JRootPane.addLayoutComponent(JRootPane.java:532)
    at java.awt.Container.addImpl(Container.java:1127)
    at java.awt.Container.add(Container.java:973)
    at Lab2Part4.<init>(Lab2Part4.java:27)
    at Lab2Part4.main(Lab2Part4.java:30)

Answer 1

contentPane.add(labelPanel, textPanel);

请将您的代码更改为

contentPane.add(labelPanel);
contentPane.add( textPanel);

参考https://www.cis.upenn.edu/~bcpierce/courses/629/jdkdocs/api/java.awt.Container.html了解更多信息

由于 java.lang.IllegalArgumentException，程序无法正常运行

Program doesn't work correctly due to java.lang.IllegalArgumentException

java

arguments

exception

jlabel