如何在Java的图形旋转(How to rotate Graphics in Java)

2019-07-17 19:00发布

我已经在得出了一些图形JPanel ，如圆形，矩形等

但是，我想画一些图形旋转特定程度的量，像一个旋转的椭圆形。我该怎么办？

Answer 1:

如果使用的是普通的Graphics ，转换为Graphics2D第一：

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（所以你只转动一两件事）：

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:

在你paintComponent()重写方法中，将图形参数的Graphics2D，调用rotate()上，使用此Graphics2D，并绘制你的椭圆。