爪哇（SWING）使用旋转

Question

我有一个应用程序与图片（只是一个全屏应用程序与3张图片在开始），我应该可以移动和旋转这些图片。所有是完美的，直到旋转，如果我旋转图片这张图片的边界保持hotizantal - >所以问题是我如何旋转组件边界在Java中？

Answer 1

下面是一些代码，我发现很久以前的事：

import java.awt.*; 
import java.awt.geom.*; 
import java.awt.image.*; 
import java.io.*; 
import java.net.*; 
import javax.imageio.*; 
import javax.swing.*; 

public class RotateImage { 
    public static void main(String[] args) throws IOException { 
     URL url = new URL("http://www.oracle.com/us/assets/im04t0-java-logo-1862786.jpg"); 
     BufferedImage original = ImageIO.read(url); 
     GraphicsConfiguration gc = getDefaultConfiguration(); 
     BufferedImage rotated1 = tilt(original, -Math.PI/2, gc); 
     BufferedImage rotated2 = tilt(original, +Math.PI/4, gc); 
     BufferedImage rotated3 = tilt(original, Math.PI, gc); 
     display(original, rotated1, rotated2, rotated3); 
    } 

    public static BufferedImage tilt(BufferedImage image, double angle, GraphicsConfiguration gc) { 
     double sin = Math.abs(Math.sin(angle)), cos = Math.abs(Math.cos(angle)); 
     int w = image.getWidth(), h = image.getHeight(); 
     int neww = (int)Math.floor(w*cos+h*sin), newh = (int)Math.floor(h*cos+w*sin); 
     int transparency = image.getColorModel().getTransparency(); 
     BufferedImage result = gc.createCompatibleImage(neww, newh, transparency); 
     Graphics2D g = result.createGraphics(); 
     g.translate((neww-w)/2, (newh-h)/2); 
     g.rotate(angle, w/2, h/2); 
     g.drawRenderedImage(image, null); 
     return result; 
    } 

    public static GraphicsConfiguration getDefaultConfiguration() { 
     GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment(); 
     GraphicsDevice gd = ge.getDefaultScreenDevice(); 
     return gd.getDefaultConfiguration(); 
    } 

    public static void display(BufferedImage im1, BufferedImage im2, BufferedImage im3, BufferedImage im4) { 
     JPanel cp = new JPanel(new GridLayout(2,2)); 
     addImage(cp, im1, "original"); 
     addImage(cp, im2, "rotate -PI/2"); 
     addImage(cp, im3, "rotate +PI/4"); 
     addImage(cp, im4, "rotate PI"); 

     JFrame f = new JFrame("RotateImage"); 
     f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     f.setContentPane(cp); 
     f.pack(); 
     f.setLocationRelativeTo(null); 
     f.setVisible(true); 
    } 

    static void addImage(Container cp, BufferedImage im, String title) { 
     JLabel lbl = new JLabel(new ImageIcon(im)); 
     lbl.setBorder(BorderFactory.createTitledBorder(title)); 
     cp.add(lbl); 
    } 
} 

编辑：

// BufferedImage result = gc.createCompatibleImage(neww, newh, transparency); 
BufferedImage result = gc.createCompatibleImage(neww, newh, Transparency.TRANSLUCENT);