java - JPanel 中的 Raisd 边框

Question

我需要重写 JPanel 并将其设为 Raisd。请参阅我的代码。

public class CustomJPanel extends JPanel {

    public CustomJPanel(int size){
        setForeground(Color.black);  //  foreground will be black
        setOpaque(false);  

    }

    @Override
    protected void paintBorder(Graphics myGraphics){
       myGraphics.setColor(Color.black);
       myGraphics.drawRoundRect(0, 0, getWidth()-1, getHeight()-1, 20, 20);

    }
}

Answer 1

Actually, i need to have a JPanel Raisd with rounded corners

边框

这是非常基本的，但它传达了想法......

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.Arc2D;
import java.awt.geom.Path2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.Border;

public class Test {

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

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

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setBorder(new MyRoundedBorder());
        }

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

        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            g2d.dispose();
        }

    }

    public static class MyRoundedBorder implements Border {

        protected static final Insets DEFAULT_INSETS = new Insets(4, 4, 4, 4);

        @Override
        public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {

            Graphics2D g2d = (Graphics2D) g.create();

            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
            g2d.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);
            g2d.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
            g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
            g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);

            g2d.setStroke(new BasicStroke(3, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
            g2d.setColor(Color.WHITE);
            Shape corner = new RoundedShape(width - 8, height - 8, 40);
            g2d.translate(x + 2, y + 2);
            g2d.draw(corner);
            g2d.transform(AffineTransform.getRotateInstance(Math.toRadians(180), (width - 8) / 2, (height - 8) / 2));
            g2d.setColor(Color.LIGHT_GRAY);
            g2d.draw(corner);

            g2d.dispose();

        }

        @Override
        public Insets getBorderInsets(Component c) {

            return DEFAULT_INSETS;

        }

        @Override
        public boolean isBorderOpaque() {

            return true;

        }

        public class RoundedShape extends Path2D.Float {

            public RoundedShape(int width, int height, int size) {

                moveTo(0, height - size);
                append(new Arc2D.Float(0, height - size, size, size, 180, 45, Arc2D.CHORD), false);
                lineTo(0, size);
                curveTo(0, 0, 0, 0, size, 0);
                lineTo(width - size / 2, 0);
                append(new Arc2D.Float(width - size, 0, size, size, 90, -45, Arc2D.CHORD), false);

            }

        }

    }

}

自定义图形

边框的问题是你无法填充它们，不是真的，它有点困惑。

这给你带来了一个问题，你想要一个非矩形组件。相反，您需要更有创意。

以下内容利用“剪切”区域以两种不同的颜色绘制 RoundRectangle2D

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.geom.GeneralPath;
import java.awt.geom.RoundRectangle2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;

public class Test {

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

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

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                JPanel panel = new JPanel(new BorderLayout());
                panel.setBorder(new EmptyBorder(10, 10, 10, 10));
                panel.setBackground(Color.RED);
                frame.setContentPane(panel);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setOpaque(false);
        }

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

        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
            g2d.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);
            g2d.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
            g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
            g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);

            Shape border = new RoundRectangle2D.Double(0, 0, getWidth() - 1, getHeight() - 1, 20, 20);
            g2d.setColor(getBackground());
            g2d.fill(border);

            GeneralPath upperClip = new GeneralPath();
            upperClip.moveTo(0, 0);
            upperClip.lineTo(getWidth() - 1, 0);
            upperClip.lineTo(0, getHeight() - 1);

            Graphics2D clipped = (Graphics2D) g2d.create();         
            clipped.setClip(upperClip);
            clipped.setColor(Color.WHITE);
            clipped.draw(border);
            clipped.dispose();

            GeneralPath lowerClip = new GeneralPath();
            lowerClip.moveTo(0, getHeight());
            lowerClip.lineTo(getWidth(), 0);
            lowerClip.lineTo(getWidth(), getHeight());

            clipped = (Graphics2D) g2d.create();            
            clipped.setClip(lowerClip);
            clipped.setColor(Color.black);
            clipped.draw(border);
            clipped.dispose();

            g2d.dispose();
        }

    }

}

LinearGradientPaint

我过去使用的一种技术是使用 LinearGradientPaint 绘制 RoundRectangle2D，这会产生“轻微”的阴影效果，从而产生理想的结果，如果您愿意尝试这些属性