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我试图将一个JPanel放在另一个之上，完全重叠。 我使用JLayeredPane使它们处于不同的“深度”，因此我可以更改深度和不透明度，以便在另一个“下”看到某个面板。 这里是一个小测试，我做了哪些工作正常：Java Swing：结合CardLayout和JLayeredPane的效果
public class LayeredCardPanel extends JPanel {
private static final String BLUE_PANEL = "blue ";
private static final String RED_PANEL = "red ";
private static final String GREEN_PANEL = "green";
private String[] panelNames = { BLUE_PANEL, RED_PANEL, GREEN_PANEL };
private Color[] panelColors = { Color.BLUE, Color.RED, Color.GREEN };
private List<JPanel> panels = new ArrayList<>();
private final int TOP_POSITION = 30;
private static final int PANELS_FIRST_POS = 10;
private JLayeredPane layeredPane;
public LayeredCardPanel() {
setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
add(createControlPanel());
layeredPane = new JLayeredPane();
////////////////////////////////////////////////////////////////
//setting layout here results in all grey, non functioning panel.
//layeredPane.setLayout(new CardLayout(0, 0));
//////////////////////////////////////////////////////////////
add(layeredPane);
//adding 3 panel
for (int i = 0; i < panelNames.length; i++) {
JPanel panel = new JPanel();
panel.setBackground(panelColors[i]);
layeredPane.add(panel);
layeredPane.setLayer(panel, PANELS_FIRST_POS + i);
panels.add(panel);
}
////////////////////////////////////////////////////////////
//setting the card here, after adding panels, works fine
layeredPane.setLayout(new CardLayout(0, 0));
//////////////////////////////////////////////////////////
}
测试结果如下：
，你可以在//////注释行之间看到，这项测试工作正常，只有当我将CardLayout设置为JLayeredPane后我添加了JPanel s到它。 在我看来，使用默认布局管理器将JPanel添加到JLayeredPane。布局（设置和更改边界以填充JLayeredPane）由稍后应用的CardLayout完成。
我的问题是：虽然这是工作，我需要的解决方案（使用一个布局管理器添加，然后取代它来实现我想要的布局）看起来不是一个优雅的解决方案。我正在寻找更好的方法来做到这一点。
这里是整个SSCE：
public class LayeredCardPanel extends JPanel {
private static final String BLUE_PANEL = "blue ";
private static final String RED_PANEL = "red ";
private static final String GREEN_PANEL = "green";
private String[] panelNames = { BLUE_PANEL, RED_PANEL, GREEN_PANEL };
private Color[] panelColors = { Color.BLUE, Color.RED, Color.GREEN };
private List<JPanel> panels = new ArrayList<>();
private final int TOP_POSITION = 30;
private static final int PANELS_FIRST_POS = 10;
private JLayeredPane layeredPane;
public LayeredCardPanel() {
setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
add(createControlPanel());
layeredPane = new JLayeredPane();
add(layeredPane);
//add 3 panel
for (int i = 0; i < panelNames.length; i++) {
JPanel panel = new JPanel();
panel.setBackground(panelColors[i]);
layeredPane.add(panel);
layeredPane.setLayer(panel, PANELS_FIRST_POS + i);
panels.add(panel);
}
layeredPane.setLayout(new CardLayout());
}
private JPanel createControlPanel() {
ActionListener aListener = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if(e.getSource() instanceof JButton) {
moveToTop(((JButton) e.getSource()).getActionCommand());
}
}
};
JPanel controls = new JPanel();
controls.setLayout(new BoxLayout(controls, BoxLayout.Y_AXIS));
JButton blueViewBtn = new JButton(BLUE_PANEL);
blueViewBtn.setActionCommand(BLUE_PANEL);
blueViewBtn.addActionListener(aListener);
controls.add(blueViewBtn);
JButton redViewBtn = new JButton(RED_PANEL);
redViewBtn.setActionCommand(RED_PANEL);
redViewBtn.addActionListener(aListener);
controls.add(redViewBtn);
JButton greenViewBtn = new JButton(GREEN_PANEL);
greenViewBtn.setActionCommand(GREEN_PANEL);
greenViewBtn.addActionListener(aListener);
controls.add(greenViewBtn);
return controls;
}
private void moveToTop(String panelName) {
for(int i = 0; i < panelNames.length; i++) {
if(panelNames[i].equals(panelName)) {
layeredPane.setLayer(panels.get(i),TOP_POSITION);
} else {
layeredPane.setLayer(panels.get(i), PANELS_FIRST_POS + i);
}
}
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame("Layered Card Panel Simulation");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JComponent newContentPane = new LayeredCardPanel();
newContentPane.setPreferredSize(new Dimension(300,100));
frame.setContentPane(newContentPane);
frame.pack();
frame.setVisible(true);
}
});
}
}
'你可以见' - 不，我们不能看到，因为你的代码不可执行。发布适当的[SSCCE]（http://sscce.org/），可以在发布代码时证明问题。 – camickr
“正如你可以在//////之间看到的那样：是的，你可以看到它。它在代码中。我加载了最小的代码来演示问题。 SSCE要长得多。 – c0der