随机生成一个形状
我正在开发一个Java屏幕保护程序项目，到目前为止，我已经完成了很多工作。 我需要代码在随机位置生成随机颜色的随机形状。 我相信我已经完成了所有随机方面的工作，但现在我只需要使用计时器以500 ms的间隔创建这些形状。 我还需要创建一个计数器来计算30个形状，然后清除屏幕并重新开始。 （我有背景和keylistener为项目的其他部分添加，但他们工作完美，万一有人想知道他们为什么在那里）。
import javax.swing.*; import java.awt.*; import java.awt.event.*; import java.util.Random; public class ScreenSaver1 extends JPanel implements ActionListener { private JFrame frame = new JFrame("FullSize"); private Rectangle rectangle; Timer t; int x1, y1; boolean full; protected void paintComponent(Graphics g) { super.paintComponent(g); int shape; shape = (int)(Math.random() * 4); } ScreenSaver1() { t = new Timer(500, this); t.setDelay(500); t.start(); // Remove the title bar, min, max, close stuff frame.setUndecorated(true); // Add a Key Listener to the frame frame.addKeyListener(new KeyHandler()); // Add this panel object to the frame frame.add(this); // Get the dimensions of the screen rectangle = GraphicsEnvironment.getLocalGraphicsEnvironment() .getDefaultScreenDevice().getDefaultConfiguration().getBounds(); // Set the size of the frame to the size of the screen frame.setSize(rectangle.width, rectangle.height); frame.setVisible(true); // Remember that we are currently at full size full = true; } // This method will run when any key is pressed in the window class KeyHandler extends KeyAdapter { public void keyPressed(KeyEvent e) { // Terminate the program. if (e.getKeyChar() == 'x') { System.out.println("Exiting"); System.exit(0); } else if (e.getKeyChar() == 'r') { System.out.println("Change background color"); setBackground(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256))); repaint(); } else if (e.getKeyChar() == 'z') { System.out.println("Resizing"); frame.setSize((int)rectangle.getWidth() / 2, (int)rectangle.getHeight()); } } } private void makeLine(Graphics g) { int x = (int)(Math.random() * rectangle.getWidth()); int y = (int)(Math.random() * rectangle.getHeight()); int x1 = (int)(Math.random() * 100); int y1 = (int)(Math.random() * 100); g.setColor(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256) )); g.drawLine(x, y, x1, y1); } private void makeRect(Graphics g) { int x = (int)(Math.random() * rectangle.getWidth()); int y = (int)(Math.random() * rectangle.getHeight()); int width = (int)(Math.random() * 100); int height = (int)(Math.random() * 100); g.setColor(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256) )); g.drawRect(x, y, width, height); } private void makeOval(Graphics g) { int x = (int)(Math.random() * rectangle.getWidth()); int y = (int)(Math.random() * rectangle.getHeight()); int width = (int)(Math.random() * 100); int height = (int)(Math.random() * 100); g.setColor(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256) )); g.drawOval(x, y, width, height); } private void makeRoundRect(Graphics g) { int x = (int)(Math.random() * rectangle.getWidth()); int y = (int)(Math.random() * rectangle.getHeight()); int width = (int)(Math.random() * 100); int height = (int)(Math.random() * 100); int arcWidth = (int)(Math.random() * width); int arcHeight = (int)(Math.random() * height); g.setColor(new Color((int)(Math.random() * 256), (int)(Math.random() * 256), (int)(Math.random() * 256) )); g.drawRoundRect(x, y, width, height, arcWidth, arcHeight); } public static void main(String[] args) { ScreenSaver1 obj = new ScreenSaver1(); } } 你不会喜欢我，但我会建议你稍微备份……
首先，Java提供了一个非常好的基本Shape接口，它定义了应该如何呈现“形状”（以及其他内容），所以相反完全重新发明轮子，我建议你从这开始。
接下来，您需要某种包装Shape （具有位置和大小信息）和Color ，例如……
public class RandomShape { private final Color color; private final Shape shape; public RandomShape(Color color, Shape shape) { this.color = color; this.shape = shape; } public Color getColor() { return color; } public Shape getShape() { return shape; } public void paint(Graphics2D g2d) { g2d.setColor(color); g2d.draw(shape); g2d.fill(shape); } }
这甚至可以自己画画。
接下来，我将创建一个包含这些形状的List …
private List shapes;
这不仅可以作为您的计数器，还可以让您更新屏幕非常简单。 当shapes List包含30个或更多项目时，您只需清除它并重新绘制屏幕即可…
接下来，您需要一个javax.swing.Timer ，用于触发更新…
这个计时器应该……
检查shapes列表是否需要清除……
随机生成Color ……
int r = (int) (Math.random() * 255); int g = (int) (Math.random() * 255); int b = (int) (Math.random() * 255); Color color = new Color(r, g, b);
随机生成形状的大小和位置……
int width = 10 + (int) (Math.random() * 40); int height = 10 + (int) (Math.random() * 40); int x = (int) (Math.random() * (getWidth() - width)); int y = (int) (Math.random() * (getHeight() - height));
随机生成基础形状……
Shape shape = null; switch (whichShape) { case 0: shape = new Line2D.Double(x, y, x + width, y + height); break; case 1: shape = new Rectangle2D.Double(x, y, width, height); break; case 2: shape = new Ellipse2D.Double(x, y, width, height); break; }
创建RandomShape ，将其添加到列表并重新绘制组件…
RandomShape randomShape = new RandomShape(color, shape); shapes.add(randomShape); repaint();
简单;）
现在，当您需要绘制组件时，您只需遍历形状列表…
@Override protected void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D) g.create(); for (RandomShape shape : shapes) { shape.paint(g2d); } g2d.dispose(); }
看看如何使用Swing Timers和使用Geometry
查看“ 使用形状 ”可以使用“形状”作为实际组件的方法。 然后，您只需将组件添加到面板，您不必担心自定义绘画。
您可以在不使用这样的循环的情况下绘制所有形状
private void paintAllShapes(Graphics g, int n) { if(n < shapes.size()) { shapes.get(n).paint((Graphics2D)g); paintAllShapes(g, n+1); } } protected void paintComponent(Graphics g) { super.paintComponent(g); paintAllShapes(g, 0); }