java - BackgroundPanel 我的背景图像覆盖了我的所有组件

Question

private JPanel contentPane;
// instance variables
private static final int FRAME_WIDTH = 400;
private static final int FRAME_HEIGHT = 350;

private static final int FRAME_X_ORIGIN = 150;
private static final int FRAME_Y_ORIGIN = 150;

private static final int BUTTON_WIDTH = 90;
private static final int BUTTON_HEIGHT = 30;
private JButton readFile;
private JButton exit;
private JButton stats;
private JButton blank;

private JPanel action;

<小时/>

public Potion() {
        // desativando logs
        LogManager.getLogManager().reset();
        Logger logger = Logger.getLogger(GlobalScreen.class.getPackage().getName());
        logger.setLevel(Level.OFF);
        //-----------------------------------------------
        //background color
        BufferedImage img = null;
        try {
             File f = new File("C:\\Users\\Gabriel\\Desktop\\mu.png");
             img = ImageIO.read(f);
             System.out.println("File " + f.toString());
        } catch (Exception e) {
            System.out.println("Cannot read file: " + e);
        }

        BackgroundPanel background = new BackgroundPanel(img, BackgroundPanel.TILED, 0.50f, 0.5f);
        //fim
        //-----------------------------------------------
        JPanel contentPane = (JPanel) getContentPane();
        contentPane.setBackground(Color.WHITE);
        contentPane.setLayout(new MigLayout());

        setContentPane(background);

        //Set the frame properties
        setSize         (FRAME_WIDTH, FRAME_HEIGHT);
        setResizable    (false);
        setTitle        ("CSCE155A Course Offerings Viewer");
        setLocation     (FRAME_X_ORIGIN, FRAME_Y_ORIGIN);

        //Create and Place the Buttons on the frame
        readFile = new JButton("Read File");
        readFile.setBounds(4, 285, BUTTON_WIDTH, BUTTON_HEIGHT);


        exit = new JButton("Exit");
        exit.setBounds(100, 285, BUTTON_WIDTH, BUTTON_HEIGHT);


        stats = new JButton("Stats");
        stats.setBounds(195, 285, BUTTON_WIDTH, BUTTON_HEIGHT);


        blank = new JButton("Clear");
        blank.setBounds(290, 285, BUTTON_WIDTH, BUTTON_HEIGHT);

        action = new JPanel(new FlowLayout());
        action.setBackground(Color.blue);
        action.add(readFile); 
        action.add(exit);
        action.add(stats);
        action.add(blank);
        contentPane.add(action);

    }

我正在使用类:BackgroundPanel 将图像添加到我的框架

//背景颜色

BufferedImage img = null;
try {
     File f = new File("C:\\Users\\Gabriel\\Desktop\\mu.png");
     img = ImageIO.read(f);
     System.out.println("File " + f.toString());
} catch (Exception e) {
    System.out.println("Cannot read file: " + e);
}

BackgroundPanel background = new BackgroundPanel(img, BackgroundPanel.TILED, 0.50f, 0.5f);

但是当我要做的时候:

setContentPane(背景)；

该图像覆盖了我所有其他面板:

action = new JPanel(new FlowLayout()); action.setBackground(Color.blue); action.add(readFile); action.add(exit); contentPane.add(action);

我的背景覆盖了我的操作面板和所有按钮，我无法解决这个问题

Answer 1

让我们看看你在做什么:

在这里创建您的BackgroundPanel对象:

BackgroundPanel background = new BackgroundPanel(img, BackgroundPanel.TILED, 0.50f, 0.5f);

在这里，您提取 JFrame 的当前 contentPane、交换之前的 contentPane

JPanel contentPane = (JPanel) getContentPane();
contentPane.setBackground(Color.WHITE);
contentPane.setLayout(new MigLayout());

现在您交换 contentPanes，使背景 JPanel 成为 contentPane 但 contentPane 变量仍然引用旧的 contentPane，即不再存在的显示

setContentPane(background);

//.... other code

现在创建一个新的 JPanel，向其中添加内容:

action = new JPanel(new FlowLayout());
action.setBackground(Color.blue);
action.add(readFile); 
action.add(exit);
action.add(stats);
action.add(blank);

然后将其添加到 contentPane 变量不再显示

contentPane.add(action);

所以当然，你的组件不会被显示。相反，将操作 JPanel 添加到背景 JPanel