I have drawn some Graphics in a JPanel, like circles, rectangles, etc.

But I want to draw some Graphics rotated a specific degree amount, like a rotated ellipse. What should I do?

解決方案

If you are using plain Graphics, cast to Graphics2D first:

Graphics2D g2d = (Graphics2D)g;

To rotate an entire Graphics2D:

g2d.rotate(Math.toRadians(degrees));

//draw shape/image (will be rotated)

To reset the rotation (so you only rotate one thing):

AffineTransform old = g2d.getTransform();

g2d.rotate(Math.toRadians(degrees));

//draw shape/image (will be rotated)

g2d.setTransform(old);

//things you draw after here will not be rotated

Example:

class MyPanel extends JPanel {

@Override

public void paintComponent(Graphics g) {

super.paintComponent(g);

Graphics2D g2d = (Graphics2D)g;

AffineTransform old = g2d.getTransform();

g2d.rotate(Math.toRadians(degrees));

//draw shape/image (will be rotated)

g2d.setTransform(old);

//things you draw after here will not be rotated

}

}