我想要做的是覆盖两个面板,其中我通过使用 JLabel 在背景面板中插入图像,并且我希望另一个较小的面板出现在同一背景图像上!这是我写的:
import javax.swing.*;
import javax.swing.text.html.ImageView;
import java.awt.*;
public class addImage extends JFrame {
private JLabel label;
private ImageIcon Image;
private JButton b;
private JPanel panel1;
private JPanel panel2;
private JLayeredPane layerpanel;
public addImage() {
// JFRame
super("First Time adding Image");
setLayout(null);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setSize(400, 400);
// JLabel containing Image
Image = new ImageIcon(getClass().getResource("image1.jpg"));
// Adding Image in JLabel
label = new JLabel(Image);
// Adding Label to panel1
panel1 = new JPanel();
panel1.add(label);
// JPanel2
panel2 = new JPanel();
panel2.setBackground(Color.darkGray);
panel2.setPreferredSize(new Dimension(200, 200));
panel2.setOpaque(true);
// LAyeredPane adding both panels
layerpanel = new JLayeredPane();
layerpanel.setLayout(new BorderLayout());
layerpanel.add(panel1, new Integer(0), 0);
layerpanel.add(panel2, new Integer(1), 1);
add(layerpanel);
}
public static void main(String[] args) {
new addImage();
}
}
执行这段代码后,除了空帧之外,我没有得到任何输出! 我收到这些错误:
Exception in thread "main" java.lang.IllegalArgumentException: cannot add to layout: constraint must be a string (or null)
at java.awt.BorderLayout.addLayoutComponent(Unknown Source)
at java.awt.Container.addImpl(Unknown Source)
at javax.swing.JLayeredPane.addImpl(Unknown Source)
at java.awt.Container.add(Unknown Source)
at addImage.<init>(addImage.java:45)
at addImage.main(addImage.java:53)
我已经检查了所有相关问题,但仍然无法找到解决方案!!!! 任何形式的帮助将不胜感激!谢谢
最佳答案
你的问题在这里:
layerpanel.setLayout(new BorderLayout());
layerpanel.add(panel1, new Integer(0), 0);
layerpanel.add(panel2, new Integer(1), 1);
这并没有帮助
setLayout(null);
JLayeredPane
现在要求您向其传递 BorderLayout
的有效约束之一(例如 BorderLayout.NORTH
)。
话虽如此,我不确定您希望通过这样做实现什么目标。
您可以通过使用 CardLayout
获得相同的效果,但困惑程度要少得多,请参阅 How to Use CardLayout了解更多详情
我可以使用类似的东西“复制”您想要的输出
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;
public class AddImage extends JFrame {
private JLabel label;
private ImageIcon Image;
private JButton b;
private JPanel panel1;
private JPanel panel2;
private JLayeredPane layerpanel;
public AddImage() {
// JFRame
super("First Time adding Image");
setLayout(new BorderLayout());
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setSize(400, 400);
// JLabel containing Image
// Image = new ImageIcon(getClass().getResource("image1.jpg"));
// Adding Image in JLabel
label = new JLabel("Help");
// Adding Label to panel1
panel1 = new JPanel();
panel1.add(label);
// JPanel2
panel2 = new JPanel();
panel2.setBackground(Color.darkGray);
panel2.setPreferredSize(new Dimension(200, 200));
panel2.setOpaque(true);
// LAyeredPane adding both panels
layerpanel = new JLayeredPane();
layerpanel.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
layerpanel.add(panel1, gbc);
layerpanel.add(panel2, gbc);
layerpanel.setLayer(panel1, new Integer(0));
layerpanel.setLayer(panel2, new Integer(1));
add(layerpanel);
}
public static void main(String[] args) {
new AddImage();
}
}
关于java - 在 JLayeredPane 上添加两个 JPanel 后没有任何输出,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36407818/