[英]Java timer action listener
could use your help homework involving swing timers, action listeners and multiple objects. 可以使用您的帮助作业,其中包括摇摆计时器,动作侦听器和多个对象。 I don't know if posting the question is allowed here but i'm having trouble with the animation, here's what i have so far
我不知道是否可以在此处发布问题,但是我在动画方面遇到了麻烦,这是我到目前为止的问题
Create a class Particle that has two double fields x and y, a constructor that initializes these fields to random values between 0 and 500, methods getX and getY that return their values, and a method void move() that randomly adds or subtracts one to each of the values of x and y.
创建一个具有两个双字段x和y的类Particle,创建一个将这些字段初始化为0到500之间的随机值的构造函数,返回其值的getX和getY方法,以及将void随机添加或减去一个的void move()方法x和y的每个值。 (The quantities added to x and y are two separate random numbers.) Next, create a class ParticleFieldWithTimer that extends JPanel.
(添加到x和y的数量是两个独立的随机数。)接下来,创建一个扩展JPanel的类ParticleFieldWithTimer。 This class should prefer to be 500 * 500 pixels in size.
此类的大小应为500 * 500像素。 Its constructor should first fill an ArrayList field with 100 Particle objects, then start a Swing Timer that ticks 25 times a second.
它的构造函数应该首先用100个粒子对象填充ArrayList字段,然后启动一个摆动计时器,每秒滴答25次。 At each tick, the action listener should first call the method move for each particle, and then call repaint.
在每个滴答声处,动作侦听器应首先为每个粒子调用move方法,然后再调用repaint。 The paintComponent method of ParticleFieldWithTimer should draw each particle as a 3*3 rectangle to its current coordinates.
ParticleFieldWithTimer的paintComponent方法应将每个粒子绘制为3 * 3矩形到其当前坐标。 Make sure that the Timer will stop when the user closes the frame
确保用户关闭框架时计时器停止
This is the ParticleFieldWithTimer class 这是ParticleFieldWithTimer类
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class ParticleFieldWithTimer extends JPanel{
private ArrayList<Particle> particle = new ArrayList<Particle>();
Timer timer;
boolean b;
public ParticleFieldWithTimer (){
this.setPreferredSize(new Dimension(500,500));
for(int i = 0; i < 100; i++) {
particle.add(new Particle());
timer = new Timer(40, new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
// change polygon data
// ...
Particle p = new Particle();
p.move();
repaint();
}
});
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
for (Particle p: particle) {
double temp1 = p.getX();
double temp2 = p.getX();
int tempX = (int) temp1;
int tempY = (int) temp2;
g2.fillRect(tempX, tempY, 3, 3);
}
}
public static void main(String[] args) {
final JFrame f = new JFrame("ParticleField");
final ParticleFieldWithTimer bb = new ParticleFieldWithTimer();
f.setLayout(new FlowLayout());
f.add(bb);
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent we) {
try {
bb.finalize();
} catch (Throwable e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
f.dispose();
}
});
f.pack();
f.setVisible(true);
}
}
This is the particle class 这是粒子类
import java.util.Random;
public class Particle {
private double x , y ;
Random r = new Random();
public Particle () {
x = r.nextDouble()*500;
y = r.nextDouble()*500;
}
public Double getX() {
return x;
}
public Double getY() {
return y;
}
public void move() {
x = r.nextInt(2) - 1;
y = r.nextInt(2) - 1;
System.out.println(x + " " + y);
}
} }
This... 这个...
for(int i = 0; i < 100; i++) {
particle.add(new Particle());
timer = new Timer(40, new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
// change polygon data
// ...
Particle p = new Particle();
p.move();
repaint();
}
});
}
Is the wrong approach, it is create a 100 Timer
s, which will affect the performance of your system. 是错误的方法,它会创建一个100
Timer
,这会影响您的系统性能。
You are also creating a new Particle
each time the timer ticks, which isn't what you really want to do either, you want to affect the Particle
s you've already created... 每次计时器计时时,您还将创建一个新的
Particle
,这也不是您真正想要做的,您想影响已经创建的Particle
。
Instead, create your particles... 相反,创建您的粒子...
for(int i = 0; i < 100; i++) {
particle.add(new Particle());
}
Then create your Timer
and within it, iterate through the particles you've already created... 然后创建您的
Timer
并在其中进行迭代,遍历您已经创建的粒子...
timer = new Timer(40, new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
for (Particle p : particle) {
p.move();
}
repaint();
}
});
Don't forget to start the timer... 不要忘记启动计时器...
timer.start();
Or change the color of the Graphics
context, which is probably still set to the background of the panel... 或更改
Graphics
上下文的颜色,它可能仍设置为面板的背景...
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.RED);
for (Particle p : particle) {
I also noted that... 我还注意到...
x = r.nextInt(2) - 1;
y = r.nextInt(2) - 1;
Isn't doing what you want. 没做你想做的。 It will always make the values between -1 and 1. Instead, you want to add the result to the x/y values...
它将始终使值在-1和1之间。相反,您想将结果添加到x / y值...
x += r.nextInt(2) - 1;
y += r.nextInt(2) - 1;
Now, this kind of made the values "drag" across the screen in a (mostly) uniform manner... 现在,这种方式使值(大多数)以统一的方式在屏幕上“拖动”。
You could try using... 您可以尝试使用...
x += r.nextBoolean() ? 1 : - 1;
y += r.nextBoolean() ? 1 : - 1;
But this ended up making them dance around in place (mostly)... 但这最终使他们在原地跳舞(大部分)...
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