java - 使包含 JPanel 的 JFrame 透明

Question

这是关于 Java Swing 应用程序的。我有一个JFramewhocontentPane设置为 a JLayer。将JLayer其边框设置为TitledBorder。这就是生成的 GUI 的样子。

我希望它JFrame是完全透明的，以便生成的 GUI 具有JLayer一个圆角矩形作为边框。只有圆角矩形应该是可见的。它周围的浅灰色不应该是可见的。怎么做到呢？

这就是最终 GUI 的样子。

这是一个说明上述问题的简短程序：

public class del extends javax.swing.JFrame {

    JPanel loginPanel;

    public del() {
        initComponents();
    }

    public void initComponents() {
        loginPanel = new javax.swing.JPanel();
        loginPanel.setBackground(new java.awt.Color(204, 204, 204));
        loginPanel.setBorder(javax.swing.BorderFactory.createTitledBorder(""));
        add(loginPanel);
        setUndecorated(true);
        setMinimumSize(new Dimension(100, 100));
        setLocation(200, 200);
    }

    public static void main(String args[]) throws Exception {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }

            java.awt.EventQueue.invokeLater(new Runnable() {
                public void run() {
                    new del().setVisible(true);
                }
            });
        }
    }
}

这是生成的 GUI：

Answer 1

继续我的评论...

这是我做的一个例子，希望对您有所帮助：

基本上覆盖componentResized(ComponentEvent e)将JFrame其形状更改为RoundRectangle2D. 然后 aJPanel添加自定义 AbstarctBorder以处理边框的圆形边缘。

import java.awt.*;
import static java.awt.GraphicsDevice.WindowTranslucency.*;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.geom.RoundRectangle2D;
import javax.swing.*;
import javax.swing.border.AbstractBorder;

public class ShapedWindowAndBorderDemo extends JFrame {

    public ShapedWindowAndBorderDemo() {
        super("Shaped Window and Border Demo");

        final JPanel panel = new JPanel() {
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(200, 200);
            }
        };
        // It is best practice to set the window's shape in
        // the componentResized method.  Then, if the window
        // changes size, the shape will be correctly recalculated.
        addComponentListener(new ComponentAdapter() {
            // Give the window an elliptical shape.
            // If the window is resized, the shape is recalculated here.
            @Override
            public void componentResized(ComponentEvent e) {
                setShape(new RoundRectangle2D.Float(panel.getX(), panel.getY(), panel.getWidth(), panel.getHeight(), 10, 10));
            }
        });


        setUndecorated(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //panel.setBorder(new CurvedBorder());//creates a single lined border
        panel.setBorder(new CurvedBorder(2, true));
        panel.add(new JButton("I am a Button"));
        add(panel);

        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }

    public static void main(String[] args) {
        // Determine what the GraphicsDevice can support.
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        GraphicsDevice gd = ge.getDefaultScreenDevice();

        //If shaped windows aren't supported, exit.
        if (!gd.isWindowTranslucencySupported(PERPIXEL_TRANSPARENT)) {
            System.err.println("Shaped windows are not supported");
            System.exit(0);
        }


        // Create the GUI on the event-dispatching thread
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new ShapedWindowAndBorderDemo();
            }
        });
    }
}

class CurvedBorder extends AbstractBorder {

    private Color wallColor = Color.gray;
    private int sinkLevel = 1;
    private boolean indent = false;

    public CurvedBorder(Color wall) {
        this.wallColor = wall;
    }

    public CurvedBorder(int sinkLevel, Color wall, boolean indent) {
        this.wallColor = wall;
        this.sinkLevel = sinkLevel;
    }

    public CurvedBorder(int sinkLevel, boolean indent) {
        this.sinkLevel = sinkLevel;
        this.indent = indent;
    }

    public CurvedBorder() {
    }

    @Override
    public void paintBorder(Component c, Graphics g, int x, int y, int w, int h) {
        super.paintBorder(c, g, x, y, w, h);
        g.setColor(getWallColor());

        for (int i = 0; i < sinkLevel; i++) {
            g.drawRoundRect(x, y, w - 1 - i, h - 1 - i, 10 - i, 10 - i);
            if (indent) {
                g.drawRoundRect(x + i, y + i, w - 1, h - 1, 10 - i, 10 - i);
            }
        }
    }

    @Override
    public boolean isBorderOpaque() {
        return true;
    }

    @Override
    public Insets getBorderInsets(Component c) {
        return new Insets(sinkLevel, sinkLevel, sinkLevel, sinkLevel);
    }

    @Override
    public Insets getBorderInsets(Component c, Insets i) {
        i.left = i.right = i.bottom = i.top = sinkLevel;
        return i;
    }

    public boolean isIndented() {
        return indent;
    }

    public int getSinkLevel() {
        return sinkLevel;
    }

    public Color getWallColor() {
        return wallColor;
    }
}

参考

• 绘制圆形矩形边框的自定义边框
• 如何创建半透明和异形窗口