如何在另一幅图像上绘制图像？

Question

我有一个关于随机城市交通网络模拟的Java项目，我设法找出了实现这个项目的方法，所以我将每个交叉点分成了一个基本上是扩展的JPanel类（名为家乐福）的部分， ......一切都运转良好，直到我陷入如何绘制车辆并让它们通过道路。

所以我的问题是如何绘制一个图像（车辆图像）在另一个图像（道路）？

Answer 1

如果这是Swing，然后在BufferedImage中绘制背景图像。使用Graphic的drawImage(...)方法在JComponent（例如JPanel的）paintComponent方法中显示此BufferedImage，然后在同一paintComponent方法中通过此方法绘制变化的图像。不要忘记首先调用super.paintComponent(...)方法。

请注意，这个问题已经在这里和其他地方提出了很多问题，正如你所期望的，有很多这类事情的例子，你可以在这里找到一些搜索。

编辑
你问：

谢谢，这是我画的firt图像（公路）

再次，你会为此创建的BufferedImage可能通过使用ImageIO.read(...)。然后，您将使用g.drawImage(...)在JPanel的paintComponent(Graphics g)方法覆盖中绘制此图。

例如...

import java.awt.Dimension; 
import java.awt.Graphics; 
import java.awt.image.*; 
import java.io.IOException; 
import java.net.MalformedURLException; 
import java.net.URL; 

import javax.imageio.ImageIO; 
import javax.swing.*; 

@SuppressWarnings("serial") 
public class IntersectionImagePanel extends JPanel { 
    private static final String INTERSECTION_LINK = "http://www.weinerlawoffice.com/" + 
     "accident-diagram.jpg"; 
    private BufferedImage intersectionImage; 

    public IntersectionImagePanel() { 
     URL imageUrl; 
     try { 
     imageUrl = new URL(INTERSECTION_LINK); 
     intersectionImage = ImageIO.read(imageUrl); 
     } catch (MalformedURLException e) { 
     e.printStackTrace(); 
     System.exit(-1); 
     } catch (IOException e) { 
     e.printStackTrace(); 
     System.exit(-1); 
     } 
    } 

    @Override 
    protected void paintComponent(Graphics g) { 
     super.paintComponent(g); 
     if (intersectionImage != null) { 
     g.drawImage(intersectionImage, 0, 0, this); 
     } 
    } 

    @Override 
    public Dimension getPreferredSize() { 
     if (intersectionImage != null) { 
     int width = intersectionImage.getWidth(); 
     int height = intersectionImage.getHeight(); 
     return new Dimension(width , height); 
     } 
     return super.getPreferredSize(); 
    } 

    private static void createAndShowGui() { 
     IntersectionImagePanel mainPanel = new IntersectionImagePanel(); 

     JFrame frame = new JFrame("IntersectionImage"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().add(mainPanel); 
     frame.pack(); 
     frame.setLocationByPlatform(true); 
     frame.setVisible(true); 
    } 

    public static void main(String[] args) { 
     SwingUtilities.invokeLater(new Runnable() { 
     public void run() { 
      createAndShowGui(); 
     } 
     }); 
    } 
} 

Answer 2

不需要延长部件的另一种方法。

import javax.swing.*; 
import java.awt.*; 
import java.awt.image.*; 
import java.awt.event.ActionListener; 
import java.awt.event.ActionEvent; 

import java.util.Random; 
import java.net.URL; 
import javax.imageio.ImageIO; 

public class ImageOnImage { 

    ImageOnImage(final BufferedImage bg, BufferedImage fg) { 
     final BufferedImage scaled = new BufferedImage(
      fg.getWidth()/2,fg.getHeight()/2,BufferedImage.TYPE_INT_RGB); 
     Graphics g = scaled.getGraphics(); 
     g.drawImage(fg,0,0,scaled.getWidth(),scaled.getHeight(),null); 
     g.dispose(); 

     final int xMax = bg.getWidth()-scaled.getWidth(); 
     final int yMax = bg.getHeight()-scaled.getHeight(); 

     final JLabel label = new JLabel(new ImageIcon(bg)); 

     ActionListener listener = new ActionListener() { 

      Random random = new Random(); 

      public void actionPerformed(ActionEvent ae) { 
       Graphics g = bg.getGraphics(); 
       int x = random.nextInt(xMax); 
       int y = random.nextInt(yMax); 

       g.drawImage(scaled, x, y, null); 
       g.dispose(); 

       label.repaint(); 
      } 
     }; 

     Timer timer = new Timer(1200, listener); 
     timer.start(); 

     JOptionPane.showMessageDialog(null, label); 
    } 

    public static void main(String[] args) throws Exception { 
     URL url1 = new URL("http://i.stack.imgur.com/lxthA.jpg"); 
     final BufferedImage image1 = ImageIO.read(url1); 

     URL url2 = new URL("http://i.stack.imgur.com/OVOg3.jpg"); 
     final BufferedImage image2 = ImageIO.read(url2); 

     //Create the frame on the event dispatching thread 
     SwingUtilities.invokeLater(new Runnable(){ 
      @Override 
      public void run() { 
       new ImageOnImage(image2, image1); 
      } 
     }); 
    } 
}