获得动态形状的鼠标检测

基本上我正在构建一张世界地图。 我知道如何有一个方形点击区域。 但是我想这样做，这样我就可以将这些国家放在一起，并能够点击这个国家。 现在很明显我不能使用方形点击区域，因为我有点重叠区域。 我可以通过查看每个像素的透明度来做到这一点吗？ 即便如此，我不知道该怎么做？

Answer 1

使用Shape.contains(Point2D) – 像这样：

此示例使用重叠椭圆来显示contains(..)方法将如何准确识别鼠标单击所在的椭圆。 但是，您所指的地图类型可能会由多个不重叠的GeneralPath对象（每个国家/地区对象）组成。

 import java.awt.Color; import java.awt.Graphics2D; import java.awt.BasicStroke; import java.awt.RenderingHints; import java.awt.event.*; import java.awt.geom.*; import java.awt.image.BufferedImage; import javax.swing.*; import java.io.File; import java.util.*; import javax.imageio.ImageIO; public class ShapeContainment { List shapes = new ArrayList(); int w = 400; int h = 100; BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); Point2D mouse = new Point2D.Double(0, 0); JLabel l; ShapeContainment() { Random r = new Random(); for (int ii = 0; ii < 10; ii++) { int x = r.nextInt(w / 2); int y = r.nextInt(h / 2); int wE = r.nextInt(w - x); int hE = r.nextInt(h - y); Ellipse2D ellipse = new Ellipse2D.Double(x, y, wE, hE); shapes.add(ellipse); } l = new JLabel(new ImageIcon(img)); MouseAdapter listener = new MouseAdapter() { @Override public void mouseClicked(MouseEvent me) { mouse = me.getPoint(); drawImage(); } }; l.addMouseListener(listener); drawImage(); JOptionPane.showMessageDialog(null, l); } public void drawImage() { Graphics2D g = img.createGraphics(); g.setColor(Color.WHITE); g.fillRect(0, 0, w, h); RenderingHints hints = new RenderingHints( RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g.setRenderingHints(hints); Color bg = new Color(0, 128, 0, 60); Color inside = new Color(0, 0, 255, 120); Color outside = new Color(255, 0, 0, 120); g.setStroke(new BasicStroke(4)); for (Ellipse2D shape : shapes) { g.setColor(bg); g.fill(shape); if (shape.contains(mouse)) { g.setColor(inside); } else { g.setColor(outside); } g.draw(shape); } g.setColor(Color.RED); int x = (int) mouse.getX(); int y = (int) mouse.getY(); g.setStroke(new BasicStroke(2)); int s = 3; g.drawLine(xs, y, x+s, y); g.drawLine(x, ys, x, y+s); l.setIcon(new ImageIcon(img)); g.dispose(); try { ImageIO.write( img, "png", new File(System.currentTimeMillis() + ".png")); } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) { Runnable run = new Runnable() { @Override public void run() { new ShapeContainment(); } }; // Swing GUIs should be created and updated on the EDT // http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html SwingUtilities.invokeLater(run); } }