这篇文章主要为大家详细介绍了Java实现简单小画板，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们可以参考一下
Java制作简单画板，包括两个类，一个主要画板类Drawpad，一个画板监听器DrawListener类。
1、Drawpad类，包括画板，画板功能设计，保存图片等
package Java课程设计;
import java.awt.Graphics;
import javax.imageio.ImageIO;
import javax.print.DocFlavor.STRING;
import javax.swing.ImageIcon;
import javax.swing.JDialog;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import java.awt.AWTException;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Shape;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import javax.swing.JButton;
import javax.swing.filechooser.FileNameExtensionFilter;
public class Drawpad {
static Color color1;
public static void main(String[] args) {
Drawpad dp = new Drawpad();
dp.initUI();
}
//创建一个JFrame图形窗口
public void initUI() {
JFrame jf = new JFrame();
jf.setTitle("创意画图板(勿拖动)");
jf.setSize(1500,1000);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//关闭时退出
jf.setLocationRelativeTo(null);//居中，不用定位窗口大小
//创建字体，之后所有的字体为该字体
Font f=new Font("方正仿宋简体", Font.BOLD, 20);
//创建画笔监听器
DrawListener dl = new DrawListener();
//创建读取图片BufferedImage(将图片加载到drawPanel面板中)和画笔g，画笔g为在保存图片上进行图画。
BufferedImage bi = new BufferedImage(1300,800, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = bi.createGraphics();
//初始化时填充白色
g.setColor(Color.WHITE);
//先将图片填充为白色
g.fillRect(0, 0, 1300,800);
//设置增加菜单栏，包括保存和新建两个按钮
JMenuBar box=new JMenuBar();
//在窗体上加菜单条,做一个菜单条,是菜单条，不是工具栏
//创建menubtn1保存按钮，并加上监听器，以图片的形式保存绘画板上的内容
JButton menubtn1=new JButton("保存");
//为保存按钮注册监听器
menubtn1.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent arg0) {
//创建文件保存窗口
JFileChooser f=new JFileChooser("保存");
int returnVal = f.showSaveDialog(null);
File file1=null;
if(returnVal == JFileChooser.APPROVE_OPTION) {
file1 =f.getSelectedFile();
String name = f.getName(file1);
try {
ImageIO.write(bi, "PNG", new File(f.getCurrentDirectory(),name+".png"));
} catch (IOException e) {
//需抛出异常
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
});
/*JButton menubtn2=new JButton("打开");
//为打开按钮注册监听器
menubtn1.addActionListener(new ActionListener(){
@Override
//获取当前画笔粗细
public void actionPerformed(ActionEvent arg0) {
BufferedImage bimg = null;
JFileChooser f=new JFileChooser("打开");
int returnVal = f.showOpenDialog(null);
File file1=null;
if(returnVal == JFileChooser.APPROVE_OPTION) {
file1 =f.getSelectedFile();
String name = f.getName(file1);
try {
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
});*/
//创建menubtn3退出按钮，并加上监听器，退出程序
JButton menubtn3=new JButton("退出");
menubtn3.addActionListener(new ActionListener(){
@Override
//获取当前画笔粗细
public void actionPerformed(ActionEvent arg0) {
int ret=JOptionPane.showConfirmDialog(null, "你确定要退出吗", "确认退出", JOptionPane.YES_NO_OPTION);
if(ret==JOptionPane.YES_OPTION){
//“确认”退出程序
System.exit(0);
}
}
});
box.add(menubtn1);
// box.add(menubtn2);
box.add(menubtn3);
//jf.setJMenuBar(box);
jf.setJMenuBar(box);
//jf用BorderLayout布局
//北边,画板模式功能栏
JPanel funcPanel=new JPanel();
jf.add(funcPanel,BorderLayout.NORTH);
//中间,画布
JPanel drawPanel=new JPanel();
jf.add(drawPanel,BorderLayout.CENTER);
drawPanel.setPreferredSize(new Dimension(1000,700));
drawPanel.setBackground(dl.background);
//一定要在画布上加上监听器!!1若画布没有加上监听器，无法显示
drawPanel.addMouseListener(dl);
drawPanel.addMouseMotionListener(dl);
//南边,为画笔颜色选择按钮
JPanel colorPanel=new JPanel();
jf.add(colorPanel,BorderLayout.SOUTH);
//右边,为选择背景颜色按钮、画笔粗细选择按钮
JPanel backgroundPanel=new JPanel();
jf.add(backgroundPanel,BorderLayout.EAST);
backgroundPanel.setPreferredSize(new Dimension(150,1000));
//左边,获取当前状态如:背景颜色、画笔颜色、画笔性质
JPanel nowPanel=new JPanel();
jf.add(nowPanel,BorderLayout.WEST);
nowPanel.setPreferredSize(new Dimension(180,1000));
//左边放入当前状态Panel
nowPanel.setBackground(Color.WHITE);
JLabel label2=new JLabel("当前背景颜色");
label2.setFont(f);
nowPanel.add(label2);
//放入当前背景颜色
JButton nowbackgroundColor=new JButton();
nowbackgroundColor.setPreferredSize(new Dimension(60,60));
nowbackgroundColor.setBackground(Color.WHITE);//背景初始化为灰色
nowPanel.add(nowbackgroundColor);
//放入当前画笔
JLabel label3=new JLabel("请选择画笔模式");
label3.setFont(f);
nowPanel.add(label3);
//放入当前画笔颜色
JButton nowColor=new JButton();
nowColor.setPreferredSize(new Dimension(60,60));
nowColor.setBackground(Color.BLACK);//画笔颜色初始化为黑色色
nowPanel.add(nowColor);
//获取当前画笔模式
JLabel label4=new JLabel("当前画笔模式");
label4.setFont(f);
nowPanel.add(label4);
JTextField text=new JTextField(dl.btncontent); //获得选择画笔模式的按钮内容，得到当前画笔模式
text.setPreferredSize(new Dimension (160,60));
text.setFont(f);
text.setEditable(false); //不可改
nowPanel.add(text);
//获取当前画笔粗细状态
JLabel label6=new JLabel("当前画笔粗细(中)"); //默认粗细为中
label6.setFont(f);
nowPanel.add(label6);
JTextField text1=new JTextField("请选择画笔粗细");
text1.setPreferredSize(new Dimension (160,60));
text1.setFont(f);
text1.setEditable(false); //不可编辑
nowPanel.add(text1);
//输入需要添加的文字
JLabel label7=new JLabel("请输入文字:");
label7.setFont(f);
nowPanel.add(label7);
JTextField text2=new JTextField();
text2.setPreferredSize(new Dimension (160,60));
text2.setFont(f);
nowPanel.add(text2);
JLabel label8=new JLabel("请输入文字样式:");
label8.setFont(f);
nowPanel.add(label8);
JTextField text3=new JTextField("方正仿宋简体");
text3.setPreferredSize(new Dimension (160,60));
text3.setFont(f);
nowPanel.add(text3);
JLabel label9=new JLabel("请输入文字大小:");
label9.setFont(f);
nowPanel.add(label9);
JTextField text4=new JTextField("20");
text4.setPreferredSize(new Dimension (160,60));
text4.setFont(f);
nowPanel.add(text4);
//为获取文字内容加一个按钮并加上监听器
JButton getcontent=new JButton("获取文字");
getcontent .setFont(f);
getcontent.setBackground(Color.YELLOW);
getcontent.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
String content=text2.getText();
String mode=text3.getText();
String size=text4.getText();
dl.mode=mode; //获取文字样式
dl.content=content; //获取文字内容
dl.size=size; //获取文字大小
}
});
nowPanel.add(getcontent);
//最后在当前状态画板中加一个清除画布内容的功能
JButton clear=new JButton("清除");
clear.setFont(f);
clear.setBackground(Color.RED);
clear.addActionListener(dl);
nowPanel.add(clear);
//添加按钮到北边（每个按钮写两行代码太多，通过数组方式添加按钮）
//加入标签（选择画笔模式）
JLabel labelh =new JLabel("选择画笔模式");
labelh.setFont(f);
funcPanel.add(labelh);
//将按钮名字保存在数组中，后依次存储
String[] btnstr= {"画笔","直线","矩形","填充矩形","圆","填充圆","弧线","喷枪","波形","分形","长方体","九宫格递归","文字","橡皮"};
//将画笔状态按钮防置panel中
for( int i=0;i<btnstr.length;i++) {
JButton btn=new JButton(btnstr[i]);
funcPanel.add(btn);
btn .setFont(f);
btn.setBackground(Color.white);
//加上画笔监听器
btn.addActionListener(dl);
//加上监听器：获取当前 画笔模式
btn.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
text.setText(btn.getText()); //在当前模式加入选取的画笔模式
}
});
};
//在BrderLayout布局SOUTH添加选择颜色按钮
JLabel label =new JLabel("选择画笔(橡皮)颜色");
label.setFont(f);
colorPanel.add(label);
//添加颜色按钮
Color[] colorArray = { Color.BLUE, Color.GREEN, Color.RED,
Color.BLACK,Color.ORANGE,Color.PINK,Color.CYAN,
Color.MAGENTA,Color.DARK_GRAY,Color.GRAY,
Color.LIGHT_GRAY,Color.YELLOW,Color.WHITE};
//在布局管理器中添加颜色按钮
for( int i=0;i<colorArray.length;i++) {
JButton button = new JButton();
button.setBackground(colorArray[i]);
button.setPreferredSize(new Dimension(50, 50));
button.addActionListener(dl);
colorPanel.add(button);
//获取当前状态的画笔颜色
button.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
nowColor.setBackground(button.getBackground()); //在当前画笔颜色按钮加入选择的按钮颜色
}
});
};
funcPanel.setBackground(Color.gray);
//添加背景主板颜色按钮，并设置监听器（背景颜色为按钮颜色）
JLabel label1=new JLabel("选择背景颜色");
label1.setFont(f);
backgroundPanel.add(label1);
Color[] backgroundArray= { Color.GREEN, Color.RED,
Color.ORANGE,Color.PINK,Color.CYAN,
Color.MAGENTA,Color.DARK_GRAY,Color.GRAY,
Color.LIGHT_GRAY,Color.YELLOW,Color.WHITE,Color.BLACK};
//将按钮加入进去
for( int i=0;i<backgroundArray.length;i++) {
JButton button = new JButton();
button.setBackground(backgroundArray[i]);
button.setPreferredSize(new Dimension(50, 50));
backgroundPanel.add(button);
//添加监听器，按下按钮改变背景颜色，同时体现当前状态
button.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent arg0) {
drawPanel.setBackground(button.getBackground()); //将背景颜色改为选取的背景颜色
color1=button.getBackground();
dl.background=color1; //将背景颜色传给DrawListener中的变量
System.out.println(color1);
g.setColor(color1);
g.fillRect(0, 0, 1300,800); //图片画笔填充背景颜色
nowbackgroundColor.setBackground(button.getBackground());
}
});
};
//添加选择画笔粗细的按钮,可选择画笔的粗细
JLabel label5=new JLabel("选择画笔粗细");
label5.setFont(f);
backgroundPanel.add(label5);
String[] Size={"细","中","粗"};
//选择画笔模式的按钮
for(int i=0;i<3;i++){
JButton graphsize=new JButton(Size[i]);
graphsize.setFont(new Font("宋体", Font.BOLD, 15));
graphsize.setBackground(Color.WHITE);
graphsize.setPreferredSize(new Dimension(50, 50));
backgroundPanel.add(graphsize);
graphsize.addActionListener(dl);
graphsize.addActionListener(new ActionListener(){
@Override
//获取当前画笔粗细
public void actionPerformed(ActionEvent e) {
text1.setText(graphsize.getText()); //获取当前画笔模式
}
});
}
jf.setVisible(true);
// 获取这个界面的ｇｒａｐｈｉｃｓ属性, 画笔 g
//Graphics2D g = (Graphics2D) drawPanel.getGraphics();
//drawPanel.paintComponent(g);
Graphics2D g1= (Graphics2D) drawPanel.getGraphics();
//为画笔添加监听器
drawPanel.addMouseListener(dl);
dl.g = g1;// 右传左
dl.g3 = g;// 右传左
}
}2、DrawListner类，画板功能监听器
package Java课程设计;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseMotionListener;
import java.awt.geom.AffineTransform;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.Color;
import java.util.ArrayList;
import java.util.Random;
import Java课程设计.Drawpad;
public class DrawListener implements MouseListener,ActionListener,MouseMotionListener {
//获取画笔
Graphics2D g;
//获取在保存图片上的画笔
Graphics2D g3;
//获取按钮内容
String btnstr;
Color background=Color.white; //背景颜色默认为白色
Color graphcolor=Color.BLACK; //画笔颜色默认为黑色
JButton btn;
int x1, y1, x2, y2;// 声明坐标变量
int x3=400;
int y3=0;
int graphsize=3;//默认为中等画笔
String btncontent="画笔"; //默认画笔模式为画笔
String content; //获取文字中的文字内容
String mode="方正仿宋简体"; //文字样式默认为“方正仿宋简体”
String size="20";
//九宫格递归方法,画出九宫格
public void dg(int x,int y,int width,int height) {
//九宫格函数，九宫格的实现
if(width<3) {
return;
}
if(width>90) {
g.fillRect(x+width/3, y+height/3, width/3, height/3);
g3.fillRect(x+width/3, y+height/3, width/3, height/3);
dg(x, y, width/3, height/3);
dg(x+width/3, y, width/3, height/3);
dg(x+(width/3)*2, y, width/3, height/3);
dg(x, y+height/3, width/3, height/3);
dg(x, y+(height/3)*2, width/3, height/3);
dg(x+width/3, y+height/3, width/3, height/3);
dg(x+width/3, y+(height/3)*2, width/3, height/3);
dg(x+(width/3)*2, y+height/3, width/3, height/3);
dg(x+(width/3)*2, y+(height/3)*2, width/3, height/3);
}
//九宫格的实现
else {
g.drawOval(x+width/3, y+height/3, width/3, height/3);
g3.drawOval(x+width/3, y+height/3, width/3, height/3);
dg(x, y, width/3, height/3);
dg(x+width/3, y, width/3, height/3);
dg(x+(width/3)*2, y, width/3, height/3);
dg(x, y+height/3, width/3, height/3);
dg(x, y+(height/3)*2, width/3, height/3);
dg(x+width/3, y+height/3, width/3, height/3);
dg(x+width/3, y+(height/3)*2, width/3, height/3);
dg(x+(width/3)*2, y+height/3, width/3, height/3);
dg(x+(width/3)*2, y+(height/3)*2, width/3, height/3);
}
}
//判断是颜色按钮还是画笔按钮,改变的全部是画笔按钮
public void actionPerformed(ActionEvent e) {
btnstr=e.getActionCommand(); //获取按钮的文字内容
//g.setColor(Color.black);
//如果为颜色按钮，将画笔改颜色
if(btnstr.equals("清除")){
//重新填充背景，同时将画笔置为背景颜色
System.out.println(background);
g.setColor(background);//保存图片画笔填充背景颜色
g.fillRect(0, 0, 1300, 800);
g3.setColor(background);//画笔重新填充背景
g3.fillRect(0, 0, 1300, 800);
g.setColor(graphcolor);
g3.setColor(graphcolor);
}
else{
if(btnstr.equals("")) {
//获取点击内容,将其内容强制转换成JButton
btn=(JButton) e.getSource();
//获取颜色按钮颜色
graphcolor=btn.getBackground();
}
//若为画笔粗细，获取粗细大小
else if(btnstr.equals("细")){
graphsize=1; //画笔大小为细，大小size为1
}
else if(btnstr.equals("中")){
graphsize=3;
}
else if(btnstr.equals("粗")){
graphsize=5;
}
else{
btncontent=btnstr; //获取画笔模式按钮的内容
}
}
}
//鼠标点击方法
@Override
public void mouseClicked(MouseEvent e) {
System.out.println("点击");
}
//鼠标按下方法
@Override
public void mousePressed(MouseEvent e) {
System.out.println("按下");
x1=e.getX();
y1 =e.getY();
}
//重写鼠标释放时的方法
@Override
public void mouseReleased(MouseEvent e) {
g.setColor(graphcolor);//获取保存画笔的颜色
g3.setColor(graphcolor); //获取画板画笔的颜色
x2=e.getX();
y2 =e.getY();
//选取画笔模式为直线时
if(btncontent.equals("直线")) {
g.setStroke(new BasicStroke(graphsize)); //保存画笔进行画图
g.drawLine(x1, y1, x2, y2);//画笔画直线
g3.setStroke(new BasicStroke(graphsize));//置画笔大小
g3.drawLine(x1, y1, x2, y2);
}
//选取画笔模式为波形时
else if(btncontent.equals("波形")) {
//波形函数
g.setStroke(new BasicStroke(graphsize)); //置画笔大小
g3.setStroke(new BasicStroke(graphsize));
double x4 = 0,y4 = 0;
double a2=1.40,b2=1.56,c2=1.40,d2=-6.56;
//波形函数
for(int i=0;i<5000;i++) {
double x5=Math.sin(a2*x4)-Math.cos(b2*y4);
double y5=Math.sin(c2*x4)-Math.cos(d2*y4);
x4=x5;
y4=y5;
int px=(int)(x5*100+x1);
int py=(int)(y5*100+y1);
//画波形
g.drawLine(px, py, px, py);
g3.drawLine(px, py, px, py);
}
}
//选取画笔模式为矩形时
else if(btncontent.equals("矩形")) {
g.setStroke(new BasicStroke(graphsize)); //获取矩形画笔的大小
g.drawRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x2-x1), Math.abs(y2-y1));//画矩形
g3.setStroke(new BasicStroke(graphsize));
g3.drawRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x2-x1), Math.abs(y2-y1));
}
//选取的画笔模式为填充矩形
else if(btncontent.equals("填充矩形")){
//画填充矩形
g.fillRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x2-x1), Math.abs(y2-y1));
g3.fillRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x2-x1), Math.abs(y2-y1));
}
//长方体函数
else if(btncontent.equals("长方体")){
g.setStroke(new BasicStroke(graphsize));//获取长方体画笔大小
g.setColor(btn.getBackground());//将画笔颜色置选择画笔颜色按钮颜色
//长方体函数
g.fillRect(Math.min(x1,x2),Math.min(y1,y2),Math.abs(x1-x2),Math.abs(y1-y2));
g3.setStroke(new BasicStroke(graphsize));
g3.setColor(btn.getBackground());
g3.fillRect(Math.min(x1,x2),Math.min(y1,y2),Math.abs(x1-x2),Math.abs(y1-y2));
int a,b,c,d;
a=Math.min(x1, x2);
b=Math.max(x1, x2);
c=Math.min(y1, y2);
d=Math.max(y1, y2);
int m=(int)((b-a)*Math.cos(Math.PI/4)*Math.sin(Math.PI/4));
int n=(int)((b-a)*Math.cos(Math.PI/4)*Math.sin(Math.PI/4));
//顶面
g.setColor(btn.getBackground());
g.fillPolygon(new int[] {a, a+m, b+m,b},new int[] {c,c-n,c-n,c},4);
//右侧面
g.setColor(btn.getBackground());
g.fillPolygon(new int[] {b, b, b+m,b+m},new int[] {c,d,d-n,c-n},4);
g3.setColor(btn.getBackground());
g3.fillPolygon(new int[] {a, a+m, b+m,b},new int[] {c,c-n,c-n,c},4);
//右侧面
g3.setColor(btn.getBackground());
g3.fillPolygon(new int[] {b, b, b+m,b+m},new int[] {c,d,d-n,c-n},4);
}
//分形函数
else if(btncontent.equals("分形")){
g.setStroke(new BasicStroke(graphsize)); //获取画笔大小
g3.setStroke(new BasicStroke(graphsize));
double x = 0,y = 0;
//分形函数实现
double a1=-1.8,b=-2.0,c=-0.5,d=-0.9;
for(int i=0;i<5000;i++) {
double x3=Math.sin(a1*y)-c*Math.cos(a1*x);
double y3=Math.sin(b*x)-d*Math.cos(b*y);
x=x3;
y=y3;
int px=(int)(x3*100+x1);
int py=(int)(y3*100+y1);
g.drawLine(px, py, px, py);
g3.drawLine(px, py, px, py);
}
}
//画圆
else if(btncontent.equals("圆")) {
g.setStroke(new BasicStroke(graphsize));//获取画笔大小
g.drawOval(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x2-x1), Math.abs(y2-y1));//画圆
g3.setStroke(new BasicStroke(graphsize));
g3.drawOval(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x2-x1), Math.abs(y2-y1));
}
//画填充圆
else if(btncontent.equals("填充圆")){
g.fillOval(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x2-x1), Math.abs(y2-y1));//画填充圆
g3.fillOval(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x2-x1), Math.abs(y2-y1));
}
//当选取模式为文字
else if(btncontent.equals("文字")){
//获取画笔大小
g.setStroke(new BasicStroke(15));
Font font = new Font(mode, Font.BOLD, Integer.parseInt(size)); //获得文字内容，文字大小，文字样式
g.setFont(font); //在画笔中置文字样式和大小
g.drawString(content, x1, y1); //写上文字内容
g3.setStroke(new BasicStroke(15));
g3.setFont(font);//放入文字样式和大小
g3.drawString(content, x1, y1);
}
//当画笔模式为弧线时
else if(btncontent.equals("弧线")){
g.setStroke(new BasicStroke(graphsize));//获取画笔大小
//弧线函数
g.drawArc(x1, y1, 100, 60, 0, 180);
g3.setStroke(new BasicStroke(graphsize));
g3.drawArc(x1, y1, 100, 60, 0, 180);
}
//九宫格递归，调用九宫格函数
else if(btncontent.equals("九宫格递归")) {
//九宫格递归实现
dg(0,50,600,600);
}
System.out.println("释放");
}
@Override
//鼠标进入方法
public void mouseEntered(MouseEvent e) {
System.out.println("进入");
}
@Override
//鼠标离开界面方法
public void mouseExited(MouseEvent e) {
System.out.println("离开");
}
@Override
public void mouseMoved(MouseEvent e) {
}
//重写鼠标移动函数
@Override
public void mouseDragged(MouseEvent e) {
g.setColor(graphcolor); //获取画笔颜色
g3.setColor(graphcolor);
// TODO Auto-generated method stub
x2=e.getX();
y2 =e.getY();
//当为画笔时
if(btncontent.equals("画笔")){
g.setStroke(new BasicStroke(graphsize)); //获取当前画笔大小
//画笔实现
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.drawLine(x1, y1, x2, y2);
g3.setStroke(new BasicStroke(graphsize));
g3.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g3.drawLine(x1, y1, x2, y2);
x1 = x2;
y1 = y2;
}
//橡皮擦
if(btncontent.equals("橡皮")){
//将画笔颜色置为背景颜色
g.setColor(background);
g3.setColor(background);
g.setStroke(new BasicStroke(30)); //将橡皮擦的大小置大小为30
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.drawLine(x1, y1, x2, y2);
g3.setStroke(new BasicStroke(30));
g3.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g3.drawLine(x1, y1, x2, y2);
x1 = x2;
y1 = y2;
//使用过后，将画笔颜色重新置为原来颜色
g.setColor(graphcolor);
g3.setColor(graphcolor);
}
//喷枪函数
else if(btncontent.equals("喷枪")){
g.setStroke(new BasicStroke(graphsize)); //不用加粗，获取画笔大小
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g3.setStroke(new BasicStroke(graphsize)); //不用加粗
g3.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
//喷枪实现函数
for(int k=0;k<20;k++){
Random i=new Random();
int a=i.nextInt(10);
int b=i.nextInt(20);
g.drawLine(x2+a, y2+b, x2+a, y2+b);
g3.drawLine(x2+a, y2+b, x2+a, y2+b);
}
}
}
}画板演示:
保存图片:
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程学习网。
沃梦达教程
本文标题为：Java实现简单小画板
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