affinetransform java_java – AffineTransform：从中心缩放形状

我正在尝试使用AffineTransform从其中心缩放矩形.我确信解决方案很明显,但我不能让它工作！这是我到目前为止测试的…

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Rectangle;

import java.awt.geom.AffineTransform;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

public class Test extends JPanel {

Test()

{

super(null);

setOpaque(true);

setBackground(Color.WHITE);

setPreferredSize(new Dimension(200,200));

}

@Override

protected void paintComponent(Graphics g1) {

super.paintComponent(g1);

Rectangle r= new Rectangle(5,5,getWidth()-10,getHeight()-10);

double cx= r.getCenterX();

double cy= r.getCenterY();

Graphics2D g=(Graphics2D)g1;

g.setColor(Color.BLACK);

AffineTransform old= g.getTransform();

for(double zoom=0.9; zoom>=0.5; zoom-=0.1)

{

AffineTransform tr2= new AffineTransform(old);

tr2.translate(-cx, -cy);

tr2.scale(zoom, zoom);

tr2.translate(cx/zoom,cy/zoom);

g.setTransform(tr2);

g.draw(r);

g.setTransform(old);

}

}

public static void main(String[] args) {

JOptionPane.showMessageDialog(null, new Test());

}

}

但它不起作用….任何建议？