Java 如何平滑JFrame形状

我给我的JFrame窗口提供了一个圆角自定义形状，但如何平滑它（抗锯齿）

很多问题将归结于您如何呈现内容，但基本概念是为您要绘制的

图形

上下文提供呈现提示

例如，如果我正在绘制一个组件，我可能会使用类似于

// Create a "copy" of the graphics context so we don't modify any of it's existing
// settings.  This makes it easier to manage the graphics context as we 
// may not want to effect anything else that might be using this graphics context
// into the future
Graphics2D g2d = (Graphics2D)g.create();
RenderingHints hints = new RenderingHints(
    RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON
);
g2d.setRenderingHints(hints);
//... continue drawing.
// Dispose of our "copy" of the graphics context
g2d.dispose();

查看更多详细信息

用示例更新

public class AATest {

    public static void main(String[] args) {
        new AATest();
    }

    public AATest() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new PaintPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class PaintPane extends JPanel {

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(215, 110);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            RenderingHints hints = new RenderingHints(
                    RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2d.setRenderingHints(hints);
            g2d.setColor(Color.RED);
            drawShape(g2d, 5, 5);
            g2d.dispose();
            g2d = (Graphics2D) g.create();
            g2d.setColor(Color.BLUE);
            drawShape(g2d, 110, 5);
            g2d.dispose();
        }

        protected void drawShape(Graphics2D g2d, int x, int y) {
            g2d.draw(new Ellipse2D.Float(x, y, 100, 100));
        }
    }
}

使用新示例更新

public class AATest {

    public static void main(String[] args) {
        new AATest();
    }

    public AATest() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new PaintPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class PaintPane extends JPanel {

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(215, 110);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            RenderingHints hints = new RenderingHints(
                    RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2d.setRenderingHints(hints);
            g2d.setColor(Color.RED);
            drawShape(g2d, 5, 5);
            g2d.dispose();
            g2d = (Graphics2D) g.create();
            g2d.setColor(Color.BLUE);
            drawShape(g2d, 110, 5);
            g2d.dispose();
        }

        protected void drawShape(Graphics2D g2d, int x, int y) {
            g2d.draw(new Ellipse2D.Float(x, y, 100, 100));
        }
    }
}

我使用的技巧之一是，我不使用“setShape”，而是简单地制作一个透明窗口，并使用自定义面板来提供我想要使用的形状

这方面的主要问题是，您现在要负责确保在形状内部绘制内容

public class ShapedWindow {

    public static void main(String[] args) {
        new ShapedWindow();
    }

    public ShapedWindow() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JWindow frame = new JWindow();
                frame.setBackground(new Color(0, 0, 0, 0));
                frame.setContentPane(new ShapedPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
                frame.setAlwaysOnTop(true);
            }
        });
    }

    public class ShapedPane extends JPanel {

        public ShapedPane() {

            setOpaque(false);
            setLayout(new GridBagLayout());

            JButton button = new JButton("Close");
            button.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    System.exit(0);
                }
            });

            add(button);

        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g); //To change body of generated methods, choose Tools | Templates.
            Graphics2D g2d = (Graphics2D) g.create();
            RenderingHints hints = new RenderingHints(
                    RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2d.setRenderingHints(hints);
            g2d.setColor(getBackground());
            g2d.fill(new Ellipse2D.Float(0, 0, getWidth(), getHeight()));
            g2d.dispose();
        }
    }

}

---

但是，你将如何保存该形状？你说的“保存该形状”是什么意思？我必须先制作一个抗锯齿形状，然后说“设置形状”（形状）。但是，如果你不能保存一个图形2D绘制的形状，我该如何设置形状呢<代码>形状是一个抽象/虚拟的概念，可以呈现到

图形

上下文中。您可以影响图形上下文的配置方式。这就是它的工作原理您显然不了解在Swing/Java中绘画是如何工作的。通读一下，你可以试着设置每像素的透明度，如下所示：你是什么意思。创建我自己的抗锯齿？您的问题是形状的边缘与背景的连接过于尖锐。你的形状可能看起来很参差不齐。如果您慢慢淡出该形状，它将看起来不那么锯齿状。像素离边界越近，它应该越半透明。但是你知道一种制作抗锯齿形状的方法吗？如果对你来说没有意义，你也可以尝试以下方法：