java 画图板重绘_JAVA学习日志之画图板重绘

画板类的代码：

package 画图板重绘;

import java.awt.FlowLayout;

import java.awt.Graphics;

import javax.swing.JButton;

import javax.swing.JFrame;

//画板类

public class Huaban {

Graphics g;

public static void main(String[] args){

Huaban hb = new Huaban();

hb.show();

}

private void show() {

JFrame jf = new JFrame();

jf.setTitle("画图板重绘");

jf.setSize(800, 800);

//设置居中显示

jf.setLocationRelativeTo(null);

jf.setLayout(new FlowLayout());

jf.setDefaultCloseOperation(3);

//在画布上创建鼠标监听器

Mouse m = new Mouse();

jf.addMouseListener(m);

//添加按钮

String[] text = {"直线","矩形"};

for(int i=0;i

{

JButton btn = new JButton(text[i]);

jf.add(btn);

btn.addActionListener(m);//给按钮添加动作监听器

}

jf.setVisible(true);

//获取画笔

Graphics g = jf.getGraphics();

//将画笔传到监听器去

m.g = g;

}

}

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