java - Swing - 不规则形状的边框

Question

我是 Swing 新手，想知道如何更好地绘制这个形状:

我有两种想法

1. 绘制常规矩形并为其编写自定义边框？
2. 绘制常规矩形+复合边框(包含2或3个边框)。但是在这里我没有成功在形状内绘制边框，有可能吗？是这样的: figure.setBorder(BorderFactory.createCompoundBorder(BorderFactory.createMatteBorder(outside top,left,bottom, right, Color.WHITE)), createMatteBorder(inside top,left,bottom, right, Color.WHITE))，其中内边框是小长方形，外面是大长方形，不知道可以吗？？？

请提供建议，我们将不胜感激!

Answer 1

看看 Java 2D API .它可以帮助您绘制复杂的形状。

例如

class IrregularShape extends JComponent {

    private int strokeWidth;

    IrregularShape(int strokeWidth){
        this.strokeWidth = strokeWidth;
    }

    @Override
    protected void paintComponent(Graphics g) {
        Graphics2D newGraphics = (Graphics2D) g.create();

        Insets borderInsets = new Insets(0, 0, 0, 0);
        Border border = getBorder();
        if (border != null) {
            borderInsets = border.getBorderInsets(this);
        }

        BasicStroke basicStroke = new BasicStroke(strokeWidth);
        newGraphics.setStroke(basicStroke);

        int x = getX() + borderInsets.left + strokeWidth;
        int y = getY() + borderInsets.top + strokeWidth;
        int width = getWidth() - x - borderInsets.right - strokeWidth;
        int height = getHeight() - y - borderInsets.bottom - strokeWidth;

        Double outterRactangleDouble = new Rectangle2D.Double(x, y, width, height);

        Area outterRectangle = new Area(outterRactangleDouble);

        Area innerRectangle = new Area(outterRactangleDouble);
        AffineTransform affineTransform = new AffineTransform();
        affineTransform.scale(0.5, 0.5);
        affineTransform.translate(x + width * 0.10, y + height * 1.2);

        innerRectangle.transform(affineTransform);
        outterRectangle.subtract(innerRectangle);
        newGraphics.draw(outterRectangle);

    }

}

public class MainFrame {

    public static void main(String[] args) {
        JFrame frame = new JFrame("Irregular Shape");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        Container contentPane = frame.getContentPane();
        contentPane.add(new IrregularShape(3));

        frame.setSize(640, 150);

        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

}

结果

而且它还可以调整大小