[英]Java Graphics2D AffineTransform Image Rotation
我试图简单地在for循环中旋转图像,如下所示:
class MyCanvas extends JComponent {
AffineTransform identity = new AffineTransform();
Image arrow;
Double angle = -180.0;
public void spin() {
angle += 10.0;
for(int i = 0; i < 10; i++) {
repaint();
System.out.println(i);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
arrow = Toolkit.getDefaultToolkit().getImage("red-arrow-right-th.png");
// Rotate + translate
AffineTransform trans = new AffineTransform();
trans.setTransform(identity);
trans.translate(getWidth()/2, getHeight()/2);
trans.rotate(Math.toRadians(angle));
System.out.println(trans);
g2.drawImage(arrow, trans, this);
g2.finalize();
}
}
但是当我在main中运行调用spin()
时,它似乎只应用一次旋转,同时仍然正确地打印出循环。 我忽略了什么?
我使用MadProgrammer的推荐改造了你的代码:
paint
,覆盖paintComponent
。 super.paint
, finalize
,特别是对自己没有创建的对象。 请注意以下内容
限定this用于从ActionListener内部类访问ImageRotationView实例。
AffineTransform.getRotateInstance
返回一个围绕锚点旋转坐标的变换。
dice.png
的文件应存在于基目录中。 。
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.Timer;
public class ImageRotationFrame {
public static void main(String[] args) {
new ImageRotationFrame();
}
public ImageRotationFrame() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame("Testing");
frame.setSize(400, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new ImageRotationComponent());
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
private class ImageRotationComponent extends JComponent {
Image arrow;
double angle = 0.0;
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
angle += 0.4;
AffineTransform trans = AffineTransform.getRotateInstance(angle, getWidth() / 2, getHeight() / 2);
((Graphics2D) g).drawImage(arrow, trans, this);
}
public ImageRotationComponent() {
try {
arrow = ImageIO.read(new File("dice.png"));
} catch (IOException e) {
e.printStackTrace();
}
int delay = 500; //milliseconds
ActionListener taskPerformer = new ActionListener() {
@Override
public void actionPerformed(ActionEvent evt) {
ImageRotationComponent.this.repaint();
}
};
new Timer(delay, taskPerformer).start();
}
}
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.