[英]java pick random images
英語不是我的母語,對於任何錯誤,我們深表歉意。 我必須用Java制作Bubble Shooter游戲。 我想將圖像用於氣泡,並且希望隨機拾取圖像。 我使用了Random
和ImageIcon
類。 我的程序在編譯時不顯示任何內容,也不知道問題出在哪里。 我是Java的初學者。
這是我的Game類的代碼:
import java.awt.Graphics;
import java.awt.Image;
import java.util.Vector;
import javax.swing.JPanel;
public class Game extends JPanel{
private static final long serialVersionUID = 1L;
//what the balls are like
public final static int START_BALLS=40;
public static Vector<Ball> balls = new Vector<Ball>();
private Image img;
private Graphics graphics;
public Game() {
for(int i=0; i<START_BALLS; i++) {
balls.add(new Ball());
}
}
public void paint(Graphics g) {
img = createImage(null);
graphics = img.getGraphics();
paintComponent(graphics);
g.drawImage(img, 0, 0, null);
repaint();
}
public void paintComponet(Graphics g) {
for(int i=0; i<balls.size(); i++) {
Ball b=(Ball)balls.get(i);
b.draw(g);
}
}
public static void main(String [] args) {
new Frame();
Game game = new Game();
new Game();
Window.window.add(game);
}
}
和氣泡類:
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.util.Random;
import javax.swing.ImageIcon;
public class Ball {
Random random = new Random();
final String[] image_paths = new String[] {"balls/peg_0.png",
"balls/peg_1.png","balls/peg_2.png","balls/peg_3.png",
"balls/peg_4.png","balls/peg_5.png"};
String randomBalls;
public Image image;
public Ball(){
randomBalls = image_paths[random.nextInt(image_paths.length)];
ImageIcon poza = new ImageIcon(randomBalls);
image=poza.getImage();
}
public void draw(Graphics g){
g.drawImage(image, 0, 0, null, null);
}
}
我的程序有什么問題?
查看我的注釋,仔細查看代碼中的注釋,看看如何重新排列類的組織。
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.util.Random;
import java.util.Vector;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import javax.imageio.ImageIO;
import java.net.URL;
public class Game extends JPanel {
Random random = new Random();
final String[] image_path = new String[]{
"http://i.stack.imgur.com/gJmeJ.png",
"http://i.stack.imgur.com/IHARa.png",
"http://i.stack.imgur.com/wCF8S.png",
"http://i.stack.imgur.com/T5uTa.png"
};
private static final long serialVersionUID = 1L;
//what the balls are like
public final static int START_BALLS = 40;
public static Vector<Ball> balls = new Vector<Ball>();
private Image img;
// A Graphics instance is typically transient.
// There is rarely, if ever, a need to store them
//private Graphics graphics;
public Game() {
for (int i = 0; i < image_path.length; i++) {
balls.add(new Ball(image_path[i]));
}
//I have no idea what you were trying to achieve here, but it fails horribly
// img = createImage(null);
img = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
// graphics = img.getGraphics();
ActionListener al = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
repaint();
}
};
Timer timer = new Timer(400, al);
timer.start();
}
@Override // very handy!
public void paintComponent(Graphics g) {
super.paintComponent(g);
// g.drawImage(img, 0, 0, null); A JPanel IS A ImageObserver
g.drawImage(img, 0, 0, this);
Ball b = (Ball) balls.get(random.nextInt(4));
b.draw(g);
}
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
JFrame f = new JFrame("Game");
f.add(new Game());
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See https://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency
SwingUtilities.invokeLater(r);
}
}
class Ball {
String randomBalls;
public Image image;
public Ball(String url) {
try {
image = ImageIO.read(new URL(url));
} catch (Exception e) {
e.printStackTrace();
}
}
public void draw(Graphics g) {
g.drawImage(image, 0, 0, null, null);
}
}
Exception in thread "AWT-EventQueue-0" java.lang.UnsupportedOperationException: getGraphics() not valid for images created with createImage(producer) at img = createImage(null);
我不知道您認為該代碼語句有什么用,但是..不好。 JPanel
進行自定義繪制時,我們應僅覆蓋paintComponent(Graphics)
並保持paint(Graphics)
方法paintComponent(Graphics)
。 覆蓋前者時,立即調用super方法。 paint(Graphics)
添加對repaint()
的調用將導致無限循環。如果代碼需要循環,請建立一個Swing計時器來調用repaint()
paintComponet(Graphics g)
應該是paintComponent(Graphics g)
適當時使用@Override
表示法。 它將警告您拼寫錯誤的方法名稱。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.