java 单击按钮实现缩放还原.docx

实现图形的缩放与还原需求：做一个绘图程序，绘制矩形 ，制作三个按钮，控制图形的缩放和还原分析：1. 创建窗体，设置窗体大小，背景色，布局2. 创建面板，实现绘图与缩放还原3. 创建三个按钮，实现事件监听，控制图形缩放实现：代码如下package cs.itcast_sharp;import java.awt.BasicStroke;import java.awt.BorderLayout;import java.awt.Color;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.geom.Rectangle2D;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.border.Border;public class ZoomSharpFrame extends JFrame private static int flag = 0; /参数private ZoomSharpFrame()initComponent();private void initComponent() / TODO Auto-generated method stub/setVisible(false);setSize(400, 400); /窗体尺寸 setLocationRelativeTo(null); /窗体放置位置 setDefaultCloseOperation(DISPOSE_ON_CLOSE); / close操作/ setBackground(Color.ORANGE);setLayout(null);getContentPane().setBackground(Color.ORANGE); /窗体背景色设为橘色 ZoomSharpPanel zPanel = new ZoomSharpPanel(); /建面板 zPanel.setBounds(100, 50, 200, 200); /面板尺寸与位置 add(zPanel); JButton j1 = new JButton(放大); /按钮和按钮监听j1.setBounds(30, 300, 80, 30);j1.addActionListener(new ActionListener() Overridepublic void actionPerformed(ActionEvent e) / TODO Auto-generated method stubflag = 1;zPanel.repaint(); /重绘System.out.println(flag:+flag););add(j1);JButton j2 = new JButton(缩小);j2.setBounds(150, 300, 80, 30); j2.addActionListener(new ActionListener() Overridepublic void actionPerformed(ActionEvent e) / TODO Auto-generated method stubflag = 2;zPanel.repaint();System.out.println(flag:+flag););add(j2);JButton j3 = new JButton(还原);j3.setBounds(270, 300, 80, 30); j3.addActionListener(new ActionListener() Overridepublic void actionPerformed(ActionEvent e) / TODO Auto-generated method stubflag = 3;zPanel.repaint();System.out.println(flag:+flag););add(j3); public class ZoomSharpPanel extends JPanel public void paint(Graphics g)Graphics2D c = (Graphics2D)g;Rectangle2D.Float rec = new Rectangle2D.Float(50,50,80,50);c.setColor(Color.RED);c.setBackground(Color.BLACK);c.setStroke(new BasicStroke(4);c.draw(rec);if(flag = 1)c.clearRect(0, 0, 220, 220);c.scale(1.5, 1.5);c.draw(rec);flag=0;else if(flag = 2)c.clearRect(0, 0, 220, 220);c.scale(0.5, 0.5);c.draw(rec);flag=0;else if(flag = 3)c.clearRect(0, 0, 220, 220);c.draw(rec);flag=0; public static voi