Java ArrayList中元素之间的Line2D

我想从它们的数组列表中的每个椭圆2d中画线。我知道我可以对每一行的位置进行硬编码，使其看起来像是连接了每一个Ellipse2D，但如果有更好的方法，我想让它与getCenterX或getCenterY或其他东西一起高效工作。我已经发布了一个我正在使用的最小的、自包含的示例

这条线显然不在正确的位置。我试图通过访问ArrayList的元素来添加坐标，但我想不出一种方法来实现它。感谢您的帮助

import java.awt.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;

public class SelfContainedExample extends JPanel {
    private ArrayList<Shape> shapes = new ArrayList<>();

    public static void main(String[] args)
    {
        EventQueue.invokeLater(new Runnable() {

            public void run() {
                createAndShowGUI();
            }
        });
    }

    public SelfContainedExample()
    {
        //Circle of Radios
        shapes.add(new Ellipse2D.Double(110, 70, 15, 15));
        shapes.add(new Ellipse2D.Double(90, 80, 15, 15));
        shapes.add(new Ellipse2D.Double(70, 100, 15, 15));
        shapes.add(new Ellipse2D.Double(70, 120, 15, 15));
        shapes.add(new Ellipse2D.Double(90, 140, 15, 15));
        shapes.add(new Ellipse2D.Double(110, 150, 15, 15));
        shapes.add(new Ellipse2D.Double(130, 140, 15, 15));
        shapes.add(new Ellipse2D.Double(150, 120, 15, 15));
        shapes.add(new Ellipse2D.Double(150, 100, 15, 15));
        shapes.add(new Ellipse2D.Double(130, 80, 15, 15));

        //for this line I want to use getCenterX() of the Ellipses added to this ArrayList
        shapes.add(new Line2D.Double(10,10,90,10));
    }

    @Override
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);

        Graphics2D g2d = (Graphics2D)g.create();
        g2d.setColor(Color.BLUE);

        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);

        for(Shape shape : shapes) {

            g2d.fill(shape);
            g2d.draw(shape);
        }

        g2d.dispose();
    }

    private static void createAndShowGUI()
    {
        //Make the big window be indented 50 pixels from each edge
        //of the screen.
        int inset = 50;
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

        JFrame frame = new JFrame("Example");
        JDesktopPane desktopPane = new JDesktopPane();
        JInternalFrame internalFrame = new JInternalFrame("Example",
                false,   //resizable
                false,   //closable
                false,   //maximizable
                true);  //iconifiable

        internalFrame.setSize(260, 260);
        internalFrame.add(new SelfContainedExample());
        internalFrame.setVisible(true);

        desktopPane.add(internalFrame);
        desktopPane.setVisible(true);
        desktopPane.setBounds(inset, inset,
                screenSize.width - inset * 7,
                screenSize.height - inset * 4);

        frame.add(desktopPane);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(desktopPane.getSize());
        frame.setLocationByPlatform( false );
        frame.setLocationRelativeTo( null );
        frame.setContentPane( desktopPane );
        frame.setVisible( true );
    }
}

---

您希望在绘制形状之前绘制线条，以便在线条的顶部绘制形状

代码类似于：

for (int i = 0; i < shapes.size() - 1; i++)
{
    Rectangle r1 = shapes.get(i).getBounds();
    Rectangle r2 = shapes.get(i+1).getBounds();

    int x1 = r1.x + r1.width / 2;
    int y1 = r1.y + r1.height / 2;

    int x2 = r2.x + r2.width / 2;
    int y2 = r2.y + r2.height / 2;

    g.drawLine(x1, y1, x2, y2);
}

for(Shape shape : shapes) {

---

您希望在绘制形状之前绘制线条，以便在线条的顶部绘制形状

代码类似于：

for (int i = 0; i < shapes.size() - 1; i++)
{
    Rectangle r1 = shapes.get(i).getBounds();
    Rectangle r2 = shapes.get(i+1).getBounds();

    int x1 = r1.x + r1.width / 2;
    int y1 = r1.y + r1.height / 2;

    int x2 = r2.x + r2.width / 2;
    int y2 = r2.y + r2.height / 2;

    g.drawLine(x1, y1, x2, y2);
}

for(Shape shape : shapes) {

---

谢谢，这太棒了。int x1=r1.x+r1.width/2；看..谢谢，这很好。int x1=r1.x+r1.width/2；看见