Java jbutton id未显示

我刚刚创建了一个简单的imagepanel，并在面板上添加了一个按钮

有谁能告诉我代码中的问题是什么

图像正在显示，但按钮未显示

package inventorymanagement;

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import javax.swing.JButton;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class ImageTest {

public static void main(String[] args) {
ImagePanel panel = new ImagePanel(new ImageIcon("E:/Desktop[/icon/6470729-exclamation-mark-icon-button-3d-red-glossy-circle.jpg").getImage());
JButton jButton1=new JButton("jButton1");
panel.add(jButton1);

JFrame frame = new JFrame();
frame.getContentPane().add(panel);
frame.pack();
frame.setVisible(true);

}
}

class ImagePanel extends JPanel {

private Image img;
public ImagePanel(String img) {
this(new ImageIcon(img).getImage());
}

public ImagePanel(Image img) {
this.img = img;
Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));
setPreferredSize(size);
setMinimumSize(size);
setMaximumSize(size);
setSize(size);
setLayout(null);
}



public void paintComponent(Graphics g) {
g.drawImage(img, 0, 0, null);
}

}

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您必须设置面板的布局

只需添加

panel.setLayout（新java.awt.FlowLayout（））面板前的code>添加（jButton1）设置布局（null）时，代码>
您需要设置所有组件的边界。您应该阅读以下教程：