java - 背景图像帮助，JPanel，JFrame，什么？

Question

我想为我正在设计的游戏制作背景图像，但我无法找到获得我想要的效果的正确方法，我想要一个可以在文本后面看到的背景等。基本上让背景覆盖整个 JFrame/JPanel 不仅仅是布局的一部分(例如 BorderLayout.Center)我认为它无论如何都会这样做，但如果它确实这样做，我如何使那些透明的背景以查看后面的背景...

我知道这很令人困惑，但我希望这里有人理解我正在尝试做的事情并可以提供帮助......这是我当前的代码。我一直在研究背景，所以不要读太多我写的内容。

import javax.swing.*;
import javax.swing.border.*;

import java.awt.*;

public class GamePanel extends JPanel {

private JTextPane playertext;
private JTextField wealthstring, currentwealth;

public GamePanel() {

    super();
    setLayout(new BorderLayout());
    setBackground(Game.getBackgroundColor());
    Border raised = BorderFactory.createRaisedBevelBorder();
    Border lowered = BorderFactory.createLoweredBevelBorder();
    setBorder(BorderFactory.createCompoundBorder(new EmptyBorder(4, 4, 4, 4), (BorderFactory.createCompoundBorder(raised, lowered))));
    add(northpanel(), BorderLayout.NORTH);
    add(eastpanel(), BorderLayout.EAST);


}


private JLabel northpanel() {

    Font northfont = new Font("Engravers MT", Font.BOLD, 12);
    ImageIcon banner = new ImageIcon("images/banner.png", "North Background");

    playertext = new JTextPane();
    playertext.setFont(northfont);
    playertext.setEditable(false);
    playertext.setText("Player: \n" + Game.getName());
    playertext.setBackground(Game.getBackgroundColor());
    playertext.setBorder(new EmptyBorder(10,10,10,10));

    wealthstring = new JTextField("Money: ");
    wealthstring.setFont(northfont);
    wealthstring.setEditable(false);
    wealthstring.setHorizontalAlignment(wealthstring.RIGHT);
    wealthstring.setBorder(null);
    wealthstring.setBackground(Game.getBackgroundColor());

    currentwealth = new JTextField();
    currentwealth.setFont(northfont);
    currentwealth.setEditable(false);
    currentwealth.setHorizontalAlignment(wealthstring.RIGHT);
    currentwealth.setBackground(Game.getBackgroundColor());
    currentwealth.setBorder(null);
    String wealthrounded = String.format("%.2f", Game.getMoney());
    currentwealth.setText(wealthrounded);

    JPanel wealthtext = new JPanel();
    wealthtext.setLayout(new GridLayout(2, 1));
    wealthtext.setBackground(Game.getBackgroundColor());
    wealthtext.setBorder(new EmptyBorder(10,10,10,10));
    wealthtext.add(wealthstring);
    wealthtext.add(currentwealth);

    JLabel northpanel = new JLabel();
    northpanel.setLayout(new BorderLayout());
    northpanel.setIcon(banner);
    northpanel.add(new JSeparator(), BorderLayout.PAGE_END);
    northpanel.add(playertext, BorderLayout.WEST);
    northpanel.add(wealthtext, BorderLayout.EAST);
    return northpanel;
}

private JPanel eastpanel() {


    JButton tab1 = new JButton("Tab 1");
    JButton tab2 = new JButton("Tab 2");
    JButton tab3 = new JButton("Tab 3");

    JPanel easttabs = new JPanel();
    easttabs.setLayout(new GridLayout(1, 3));
    easttabs.add(tab1);
    easttabs.add(tab2);
    easttabs.add(tab3);

    JPanel eastpanels = new JPanel();
    eastpanels.setLayout(new BorderLayout());
    eastpanels.setBackground(Game.getBackgroundColor());
    eastpanels.add(easttabs, BorderLayout.NORTH);

    return eastpanels;
}

}

Answer 1

因此，如果您已经有一个以图像作为背景的 JPanel，并且想要使用组件在其上添加另一个面板，则可以使用不透明度来实现此目的。只有添加到此面板的组件才是可见的。代码如下:

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;

import javax.swing.JPanel;

public class TransparentPane extends JPanel {

    public TransparentPane() {

        setOpaque(false);

    }

    @Override
    protected void paintComponent(Graphics g) {


        super.paintComponent(g);


        Graphics2D g2d = (Graphics2D) g.create();

        g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0f));

        g2d.setColor(getBackground());
        g2d.fill(getBounds());

        g2d.dispose();

    }

}