如何在Java中旋转图形

我在JPanel绘制了一些图形，如圆形，矩形等。

但我想绘制一些特定程度旋转的图形，如旋转的椭圆。 我该怎么办？

Answer 1

如果您使用的是普通Graphics ，请首先转换为Graphics2D ：

 Graphics2D g2d = (Graphics2D)g; 

要旋转整个Graphics2D ：

 g2d.rotate(Math.toRadians(degrees)); //draw shape/image (will be rotated) 

要重置旋转（所以你只旋转一件事）：

 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 

例：

 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 } } 

Answer 2

在paintComponent()重写方法中，将Graphics参数强制转换为Graphics2D，在此Graphics2D上调用rotate() ，然后绘制椭圆。