我正试图在我的
java窗口上移动一列火车并遇到严重问题.我有一个火车课,我在那里制作了火车,还有一个驾驶课,它应该可以移动火车.我需要让整列火车从右向左移动,直到它“通过”屏幕的左边缘.然后添加一个if语句来更改dx,以便列车在右侧重新启动.以下是我尝试过的但是没有用.有人可以帮我吗?
public class Driver extends GraphicsProgram
{
//~ Instance/static variables .............................................
private static final int N_STEPS = 1000;
private static final int PAUSE_TIME = 20;
private static final double TRAIN_LENGTH = 320;
//~ Constructor ...........................................................
// ----------------------------------------------------------
/**
* The run() method of the Driver Class.
* Creates an instance of the Train Class.
* Responsible for animating the train across the screen.
*/
public void run()
{
Train train = new Train(getGCanvas());
for (int i = 0; i < N_STEPS; i++) {
train.move(-100, 0);
pause(PAUSE_TIME);
}
最佳答案 这是一个用摇摆做的小演示.只需用火车图像替换黑色矩形就可以了.
诀窍是使用单独的线程(或计时器)来进行动画循环(通常称为游戏循环).循环仅告诉窗口重绘自己,并且在每次重绘时,首先计算动画对象的新位置,然后绘制它们.
import javax.swing.*;
import java.awt.*;
public class TrainDemo {
public static void main(String[] args) {
JFrame frame = new JFrame("Train Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(800, 400);
frame.setLocationRelativeTo(null);
frame.add(new TrainCanvas());
frame.setVisible(true);
}
}
class TrainCanvas extends JComponent {
private int lastX = 0;
public TrainCanvas() {
Thread animationThread = new Thread(new Runnable() {
public void run() {
while (true) {
repaint();
try {Thread.sleep(10);} catch (Exception ex) {}
}
}
});
animationThread.start();
}
public void paintComponent(Graphics g) {
Graphics2D gg = (Graphics2D) g;
int w = getWidth();
int h = getHeight();
int trainW = 100;
int trainH = 10;
int trainSpeed = 3;
int x = lastX + trainSpeed;
if (x > w + trainW) {
x = -trainW;
}
gg.setColor(Color.BLACK);
gg.fillRect(x, h/2 + trainH, trainW, trainH);
lastX = x;
}
}