主要的问题（我可以看到）是
Graphics上下文的转换，它与旋转将发生的位置相抵消。
默认情况下，我“认为”旋转发生在
Graphics上下文的左上角（0x0位置，你已将其转换为其他位置），这可能导致图像旋转出帧（或可见区域） ）
你应该提供旋转发生的“锚点”，通常，中心是我的个人喜好。
以下示例仅具有一个主图像（由于尺寸限制，我不得不对其进行缩放，但你可能不需要此图像）。然后，我用它生成一个“旋转的”实例，该实例的大小允许图像适合放入其中。trig带来了很多乐趣-我从某个地方偷了代码，因此归功于该开发人员。
该示例允许你单击任意位置，它将更改旋转轴，因此你可以看到发生了什么。默认位置是窗格的中心…
import java.awt.BorderLayout;import java.awt.Color;import java.awt.Dimension;import java.awt.EventQueue;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.Point;import java.awt.event.MouseAdapter;import java.awt.event.MouseEvent;import java.awt.geom.AffineTransform;import java.awt.image.BufferedImage;import java.io.File;import java.io.IOException;import javax.imageio.ImageIO;import javax.swing.Jframe;import javax.swing.JPanel;import javax.swing.JSlider;import javax.swing.UIManager;import javax.swing.UnsupportedLookAndFeelException;import javax.swing.event.ChangeEvent;import javax.swing.event.ChangeListener;public class SampleRotation { public static void main(String[] args) { new SampleRotation(); } public SampleRotation() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { ex.printStackTrace(); } final RotationPane rotationPane = new RotationPane(); final JSlider slider = new JSlider(0, 100); slider.addChangeListener(new ChangeListener() { @Override public void stateChanged(ChangeEvent e) { double angle = 720d * (slider.getValue() / 100d); rotationPane.setAngle(angle); } }); slider.setValue(0); Jframe frame = new Jframe("Testing"); frame.setDefaultCloseOperation(Jframe.EXIT_ON_CLOSE); frame.add(rotationPane); frame.add(slider, BorderLayout.SOUTH); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } public class RotationPane extends JPanel { private BufferedImage img; private BufferedImage rotated; private double angle; private Point clickPoint; public RotationPane() { try { img = ImageIO.read(new File("/Users/swhitehead/Dropbox/MegaTokyo/issue459.jpg")); BufferedImage scaled = new BufferedImage(img.getWidth() / 2, img.getHeight() / 2, BufferedImage.TYPE_INT_ARGB); Graphics2D g2d = scaled.createGraphics(); g2d.setTransform(AffineTransform.getScaleInstance(0.5d, 0.5d)); g2d.drawImage(img, 0, 0, this); g2d.dispose(); img = scaled; setAngle(0d); } catch (IOException ex) { ex.printStackTrace(); } addMouseListener(new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { clickPoint = e.getPoint(); repaint(); } }); } public void setAngle(double angle) { this.angle = angle; double rads = Math.toRadians(getAngle()); double sin = Math.abs(Math.sin(rads)), cos = Math.abs(Math.cos(rads)); int w = img.getWidth(); int h = img.getHeight(); int newWidth = (int) Math.floor(w * cos + h * sin); int newHeight = (int) Math.floor(h * cos + w * sin); rotated = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_ARGB); Graphics2D g2d = rotated.createGraphics(); AffineTransform at = new AffineTransform(); at.translate((newWidth - w) / 2, (newHeight - h) / 2); int x = clickPoint == null ? w / 2 : clickPoint.x; int y = clickPoint == null ? h / 2 : clickPoint.y; at.rotate(rads, x, y); g2d.setTransform(at); g2d.drawImage(img, 0, 0, this); g2d.setColor(Color.RED); g2d.drawRect(0, 0, newWidth - 1, newHeight - 1); g2d.dispose(); repaint(); } public double getAngle() { return angle; } @Override public Dimension getPreferredSize() { return img == null ? new Dimension(200, 200) : new Dimension(img.getWidth(this), img.getHeight(this)); } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); if (rotated != null) { Graphics2D g2d = (Graphics2D) g.create(); int x = (getWidth() - rotated.getWidth()) / 2; int y = (getHeight() - rotated.getHeight()) / 2; g2d.drawImage(rotated, x, y, this); g2d.setColor(Color.RED); x = clickPoint == null ? getWidth() / 2 : clickPoint.x; y = clickPoint == null ? getHeight()/ 2 : clickPoint.y; x -= 5; y -= 5; g2d.drawOval(x, y, 10, 10); g2d.dispose(); } } } }
