在JPanel中创建无数个对象,并通过Java中的PaintComponent绘制它们
作者:互联网
我有一个难题,如何实现应用.我有宽度为288,高度为512的JPanel,然后创建了两个对象(图像)并使用坐标将它们绘制到paintComponent中
drawImage (Image1,288,128,this) ;
drawImage (Image2, 288, 384, this);
.它们在X轴上同时递减,当它达到x = 144时,应在坐标'(x = 288,y =(int)Math.random()* 512)处绘制新的(相同)图像,然后开始递减以及第一个应该减少.这个过程应该是无止境的.每个达到x = 144的新对象都应建立新对象.我试图创建在其中添加坐标的ArrayList
ArrayList arrayX = new ArrayList();
arrayX.add(288)
arrayY.add((int) Math.random()* 512 )
然后通过提取值
array.get()
但这是不成功的.
我看过视频,那里的人是通过数组使用JavaScript的
var position = []
position = ({
X : 288
Y : 256
})
然后像这样通过循环实现
function draw() {
for (int i = 0; i < position.length; i++ ){
cvs.drawImage(Image1,position[i].x , position[i].y)
cvs.drawImage(Image2,position[i].x , position[i].y + 50)
position [i] .x - -;
if(position[i].x == 128)
position.push({
X : 288
Y : Math.floor(Math.random()*512 })
})
}
}
我不知道如何用Java做到这一点.
也许我也应该使用array来保持变量的坐标,或者arraylist,但是以不同的方式.请帮帮我 .
提前致谢
解决方法:
我的回答完全基于MadProgrammer’s answer(实际上是综合教程).
从我在帖子中看到的内容:“每个达到x = 144的新对象都应该构建新对象”,我认为所需的实现略有不同:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class ImageAnimator {
public ImageAnimator() {
SwingUtilities.invokeLater(() -> {
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new AnimationPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
});
}
public static class Drawable {
private int x;
private final int y;
private static final Image image = image();
//construct with a random y value
public Drawable(int x) {
this(x, -1);
}
public Drawable(int x, int y) {
this.x = x;
this.y = y < 0 ? (int) (Math.random() * (512 - 20)) : y;
}
public int getX() { return x; }
public int getY() { return y; }
public void update() { x--; }
public Image getImage(){ return image; }
public static Image image() {
URL url = null;
try {
url = new URL("https://dl1.cbsistatic.com/i/r/2017/09/24/b2320b25-27f3-4059-938c-9ee4d4e5cadf/thumbnail/32x32/707de8365496c85e90c975cec8278ff5/iconimg241979.png");
return ImageIO.read(url);
} catch ( IOException ex) {
ex.printStackTrace();
return null;
}
}
}
public class AnimationPane extends JPanel {
private final List<Drawable> drawables;
private static final int W = 288, H = 512, CYCLE_TIME = 5;
public AnimationPane() {
drawables = new ArrayList<>(2);
drawables.add(new Drawable(W, H/4));
drawables.add(new Drawable(W, 3*H/4));
Timer timer = new Timer(CYCLE_TIME, e -> animate());
timer.start();
}
private void animate() {
for (Drawable drawable : new ArrayList<>(drawables)) {
drawable.update();
if(drawable.getX() == W/2) {
drawables.add(new Drawable(W)); //random Y
}
if(drawable.getX() <= 0) {
drawables.remove(drawable);
}
}
repaint();
}
@Override
public Dimension getPreferredSize() {
return new Dimension(W, H);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (Drawable drawable : drawables ) {
g.drawImage(drawable.getImage(),drawable.getX(), drawable.getY(), null);
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(()->new ImageAnimator());
}
}
标签:swing,jpanel,drawimage,java 来源: https://codeday.me/bug/20191024/1923599.html