Question

我有以下内容：

public class Frame {

public static void main(String[] args) {

    JFrame frame = new JFrame("Frame Demo");

    Panel panel = new Panel();        

    frame.add(panel);        

    frame.setBounds(250,100,800,500);
    frame.setVisible(true);
}
}

public class Panel extends JPanel {

JButton singlePlayerButton;
JButton multiPlayerButton;

BufferedImage image;

Gui gui;


public Panel() {
    gui = new Gui();
    add(gui);

    try {
        image = ImageIO.read(new File("C:\\Users\\void\\workspace\\BattleShips\\src\\Testumgebung\\background\\battleship_main.jpg"));

    } catch (IOException e) {
        e.getMessage();
        e.printStackTrace();
    }

}

public void paintComponent(Graphics g) {
    g.drawImage(image, 0, 0, this.getWidth(), this.getHeight(), null);
}


JLabel text;
JPanel mainMenuPanel;


private class Gui extends JPanel {

    public Gui() {

    setVisible(true);
    setSize(500, 300);
    setLayout(null);

    mainMenuPanel = new JPanel();

    mainMenuPanel.setLayout(null);
    mainMenuPanel.setBackground(Color.BLUE);
    mainMenuPanel.setBounds(150, 10, 200, 230);
    add(mainMenuPanel);
    mainMenuPanel.setVisible(true);


    singlePlayerButton = new JButton("Single Player");
    singlePlayerButton.setBounds(100,50 , 150, 40);

    singlePlayerButton.setVisible(true);

    mainMenuPanel.add(singlePlayerButton);

    multiPlayerButton = new JButton("Multi Player");
    multiPlayerButton.setBounds(100, 100, 150, 40);

    multiPlayerButton.setVisible(true);
    mainMenuPanel.add(multiPlayerButton);

    repaint();
}

}
}

我只想要一个带有BackgroundImage的MainMenu和像Singleplayer等的按钮。我必须设置一个布局，还是没有一个布局。我刚开始使用GUI，你可以从代码中假设。提前谢谢......

Answer 1

我是否必须设置布局，或者没有一个

作为一般的经验法则，是的，您应该尽可能使用布局管理器，从长远来看，它将为您节省大量的工作。

基于你的代码和我想你想做的事情，我建议你看一下：

作为补充建议：

不要使用getClass().getResource("/Testumgebung/background/battleship_main.jpg")布局，像素完美布局是现代ui设计中的幻觉。影响组件个体大小的因素太多，您无法控制。 Swing旨在与布局管理器一起工作，放弃这些将导致问题和问题的结束，您将花费越来越多的时间来纠正
永远不要引用super.paintComponent，一旦导出程序就不会存在。尝试并避免使用绝对路径，因为不同的计算机会将您的程序放在不同的位置（并非所有操作系统都有驱动器号的概念）。相反，在您的情况下，您应该使用类似setOpaque(false)
作为一般规则，您应该在执行任何自定义绘画之前调用Panel。
为了显示您的背景，添加到其中的所有组件都应该透明（Gui），以便背景显示。
将您的班级分成责任范围。例如，Panel除了管理背景图片之外什么都不做，不应该管理任何其他内容，这意味着将Panel添加到import java.awt.AlphaComposite; import java.awt.BorderLayout; import java.awt.CardLayout; import java.awt.Color; import java.awt.Composite; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.image.BufferedImage; import java.io.IOException; import javax.imageio.ImageIO; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; public class Frame { public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { ex.printStackTrace(); } Panel background = new Panel(); JFrame frame = new JFrame("Testing"); frame.setContentPane(background); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.add(new Gui()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } public static class Panel extends JPanel { BufferedImage image; public Panel() { setLayout(new BorderLayout()); try { image = ImageIO.read(getClass().getResource("/Testumgebung/background/battleship_main.png")); } catch (IOException e) { e.printStackTrace(); } } @Override public Dimension getPreferredSize() { return image == null ? super.getPreferredSize() : new Dimension(image.getWidth(), image.getHeight()); } @Override public void paintComponent(Graphics g) { super.paintComponent(g); g.drawImage(image, 0, 0, this); } } public static class Gui extends JPanel { private MainMenuPane mainMenuPane; private CardLayout cardLayout; public Gui() { setOpaque(false); setVisible(true); cardLayout = new CardLayout(); setLayout(cardLayout); mainMenuPane = new MainMenuPane(); // Other views add(mainMenuPane, "MainMenu"); cardLayout.show(this, "MainMenu"); } } public static class MainMenuPane extends JPanel { JButton singlePlayerButton; JButton multiPlayerButton; JLabel text; public MainMenuPane() { setLayout(new GridBagLayout()); setOpaque(false); setBackground(Color.BLUE); GridBagConstraints gbc = new GridBagConstraints(); gbc.ipadx = 20; gbc.ipady = 20; singlePlayerButton = new JButton("Single Player"); add(singlePlayerButton, gbc); multiPlayerButton = new JButton("Multi Player"); add(multiPlayerButton, gbc); } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); // This is faking transparency, so the background color // will be see through Graphics2D g2d = (Graphics2D) g.create(); Composite old = g2d.getComposite(); g2d.setComposite(AlphaComposite.SrcOver.derive(0.5f)); g2d.fillRect(0, 0, getWidth(), getHeight()); g2d.setComposite(old); } } }作为单独的步骤，而不是aa: { one: "hello", two: "good", three: "bye", four: "tomorrow", }, "bb": { "1": "a quick fox", "2": "a slow bird", "3": "a smart dog", "4": "a wilf flowert",初始化

作为一个概念性的例子......

Be free

: ("(.*?)")

带背景图片和JPanel的JFrame

1 个答案: