java 实现 简单画图功能(简单点的)

Posted 2023-03-02

来个参考的...
和记事本样式
菜单条

菜单2个 --
选择图形(直线 矩形 椭圆)
画笔颜色 (红色 绿色 蓝色)

选种相应属性后 在下面的面板画...

楼主给你一个我编的，直接保存成pb.java编译运行，就是你要的画图功能
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import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import java.awt.geom.*;
import java.io.*;

class Point implements Serializable

int x,y;
Color col;
int tool;
int boarder;

Point(int x, int y, Color col, int tool, int boarder)

this.x = x;
this.y = y;
this.col = col;
this.tool = tool;
this.boarder = boarder;



class paintboard extends Frame implements ActionListener,MouseMotionListener,MouseListener,ItemListener

int x = -1, y = -1;
int con = 1;//画笔大小
int Econ = 5;//橡皮大小

int toolFlag = 0;//toolFlag:工具标记
//toolFlag工具对应表：
//（0--画笔）；（1--橡皮）；（2--清除）；
//（3--直线）；（4--圆）；（5--矩形）；

Color c = new Color(0,0,0); //画笔颜色
BasicStroke size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);//画笔粗细
Point cutflag = new Point(-1, -1, c, 6, con);//截断标志

Vector paintInfo = null;//点信息向量组
int n = 1;

FileInputStream picIn = null;
FileOutputStream picOut = null;

ObjectInputStream VIn = null;
ObjectOutputStream VOut = null;

// *工具面板--画笔，直线，圆，矩形，多边形,橡皮，清除*/
Panel toolPanel;
Button eraser, drLine,drCircle,drRect;
Button clear ,pen;
Choice ColChoice,SizeChoice,EraserChoice;
Button colchooser;
Label 颜色,大小B,大小E;
//保存功能
Button openPic,savePic;
FileDialog openPicture,savePicture;

paintboard(String s)

super(s);
addMouseMotionListener(this);
addMouseListener(this);

paintInfo = new Vector();

/*各工具按钮及选择项*/
//颜色选择
ColChoice = new Choice();
ColChoice.add("black");
ColChoice.add("red");
ColChoice.add("blue");
ColChoice.add("green");
ColChoice.addItemListener(this);
//画笔大小选择
SizeChoice = new Choice();
SizeChoice.add("1");
SizeChoice.add("3");
SizeChoice.add("5");
SizeChoice.add("7");
SizeChoice.add("9");
SizeChoice.addItemListener(this);
//橡皮大小选择
EraserChoice = new Choice();
EraserChoice.add("5");
EraserChoice.add("9");
EraserChoice.add("13");
EraserChoice.add("17");
EraserChoice.addItemListener(this);
////////////////////////////////////////////////////
toolPanel = new Panel();

clear = new Button("清除");
eraser = new Button("橡皮");
pen = new Button("画笔");
drLine = new Button("画直线");
drCircle = new Button("画圆形");
drRect = new Button("画矩形");

openPic = new Button("打开图画");
savePic = new Button("保存图画");

colchooser = new Button("显示调色板");

//各组件事件监听
clear.addActionListener(this);
eraser.addActionListener(this);
pen.addActionListener(this);
drLine.addActionListener(this);
drCircle.addActionListener(this);
drRect.addActionListener(this);
openPic.addActionListener(this);
savePic.addActionListener(this);
colchooser.addActionListener(this);

颜色 = new Label("画笔颜色",Label.CENTER);
大小B = new Label("画笔大小",Label.CENTER);
大小E = new Label("橡皮大小",Label.CENTER);
//面板添加组件
toolPanel.add(openPic);
toolPanel.add(savePic);

toolPanel.add(pen);
toolPanel.add(drLine);
toolPanel.add(drCircle);
toolPanel.add(drRect);

toolPanel.add(颜色); toolPanel.add(ColChoice);
toolPanel.add(大小B); toolPanel.add(SizeChoice);
toolPanel.add(colchooser);

toolPanel.add(eraser);
toolPanel.add(大小E); toolPanel.add(EraserChoice);

toolPanel.add(clear);
//工具面板到APPLET面板
add(toolPanel,BorderLayout.NORTH);

setBounds(60,60,900,600); setVisible(true);
validate();
//dialog for save and load

openPicture = new FileDialog(this,"打开图画",FileDialog.LOAD);
openPicture.setVisible(false);
savePicture = new FileDialog(this,"保存图画",FileDialog.SAVE);
savePicture.setVisible(false);

openPicture.addWindowListener(new WindowAdapter()

public void windowClosing(WindowEvent e)
openPicture.setVisible(false);
);

savePicture.addWindowListener(new WindowAdapter()

public void windowClosing(WindowEvent e)
savePicture.setVisible(false);
);

addWindowListener(new WindowAdapter()

public void windowClosing(WindowEvent e)
System.exit(0);
);



public void paint(Graphics g)

Graphics2D g2d = (Graphics2D)g;

Point p1,p2;

n = paintInfo.size();

if(toolFlag==2)
g.clearRect(0,0,getSize().width,getSize().height);//清除

for(int i=0; i<n ;i++)
p1 = (Point)paintInfo.elementAt(i);
p2 = (Point)paintInfo.elementAt(i+1);
size = new BasicStroke(p1.boarder,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);

g2d.setColor(p1.col);
g2d.setStroke(size);

if(p1.tool==p2.tool)

switch(p1.tool)

case 0://画笔

Line2D line1 = new Line2D.Double(p1.x, p1.y, p2.x, p2.y);
g2d.draw(line1);
break;

case 1://橡皮
g.clearRect(p1.x, p1.y, p1.boarder, p1.boarder);
break;

case 3://画直线
Line2D line2 = new Line2D.Double(p1.x, p1.y, p2.x, p2.y);
g2d.draw(line2);
break;

case 4://画圆
Ellipse2D ellipse = new Ellipse2D.Double(p1.x, p1.y, Math.abs(p2.x-p1.x) , Math.abs(p2.y-p1.y));
g2d.draw(ellipse);
break;

case 5://画矩形
Rectangle2D rect = new Rectangle2D.Double(p1.x, p1.y, Math.abs(p2.x-p1.x) , Math.abs(p2.y-p1.y));
g2d.draw(rect);
break;

case 6://截断，跳过
i=i+1;
break;

default :
//end switch
//end if
//end for


public void itemStateChanged(ItemEvent e)

if(e.getSource()==ColChoice)//预选颜色

String name = ColChoice.getSelectedItem();

if(name=="black")
c = new Color(0,0,0);
else if(name=="red")
c = new Color(255,0,0);
else if(name=="green")
c = new Color(0,255,0);
else if(name=="blue")
c = new Color(0,0,255);

else if(e.getSource()==SizeChoice)//画笔大小

String selected = SizeChoice.getSelectedItem();

if(selected=="1")

con = 1;
size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);


else if(selected=="3")

con = 3;
size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);


else if(selected=="5")
con = 5;
size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);


else if(selected=="7")
con = 7;
size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);


else if(selected=="9")
con = 9;
size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);



else if(e.getSource()==EraserChoice)//橡皮大小

String Esize = EraserChoice.getSelectedItem();

if(Esize=="5")
Econ = 5*2;
else if(Esize=="9")
Econ = 9*2;
else if(Esize=="13")
Econ = 13*2;
else if(Esize=="17")
Econ = 17*3;





public void mouseDragged(MouseEvent e)

Point p1 ;
switch(toolFlag)
case 0://画笔
x = (int)e.getX();
y = (int)e.getY();
p1 = new Point(x, y, c, toolFlag, con);
paintInfo.addElement(p1);
repaint();
break;

case 1://橡皮
x = (int)e.getX();
y = (int)e.getY();
p1 = new Point(x, y, null, toolFlag, Econ);
paintInfo.addElement(p1);
repaint();
break;

default :



public void mouseMoved(MouseEvent e)

public void update(Graphics g)

paint(g);


public void mousePressed(MouseEvent e)

Point p2;
switch(toolFlag)
case 3://直线
x = (int)e.getX();
y = (int)e.getY();
p2 = new Point(x, y, c, toolFlag, con);
paintInfo.addElement(p2);
break;

case 4: //圆
x = (int)e.getX();
y = (int)e.getY();
p2 = new Point(x, y, c, toolFlag, con);
paintInfo.addElement(p2);
break;

case 5: //矩形
x = (int)e.getX();
y = (int)e.getY();
p2 = new Point(x, y, c, toolFlag, con);
paintInfo.addElement(p2);
break;

default :



public void mouseReleased(MouseEvent e)

Point p3;
switch(toolFlag)
case 0://画笔
paintInfo.addElement(cutflag);
break;

case 1: //eraser
paintInfo.addElement(cutflag);
break;

case 3://直线
x = (int)e.getX();
y = (int)e.getY();
p3 = new Point(x, y, c, toolFlag, con);
paintInfo.addElement(p3);
paintInfo.addElement(cutflag);
repaint();
break;

case 4: //圆
x = (int)e.getX();
y = (int)e.getY();
p3 = new Point(x, y, c, toolFlag, con);
paintInfo.addElement(p3);
paintInfo.addElement(cutflag);
repaint();
break;

case 5: //矩形
x = (int)e.getX();
y = (int)e.getY();
p3 = new Point(x, y, c, toolFlag, con);
paintInfo.addElement(p3);
paintInfo.addElement(cutflag);
repaint();
break;

default:



public void mouseEntered(MouseEvent e)

public void mouseExited(MouseEvent e)

public void mouseClicked(MouseEvent e)

public void actionPerformed(ActionEvent e)


if(e.getSource()==pen)//画笔
toolFlag = 0;

if(e.getSource()==eraser)//橡皮
toolFlag = 1;

if(e.getSource()==clear)//清除

toolFlag = 2;
paintInfo.removeAllElements();
repaint();


if(e.getSource()==drLine)//画线
toolFlag = 3;

if(e.getSource()==drCircle)//画圆
toolFlag = 4;

if(e.getSource()==drRect)//画矩形
toolFlag = 5;

if(e.getSource()==colchooser)//调色板

Color newColor = JColorChooser.showDialog(this,"调色板",c);
c = newColor;


if(e.getSource()==openPic)//打开图画


openPicture.setVisible(true);

if(openPicture.getFile()!=null)

int tempflag;
tempflag = toolFlag;
toolFlag = 2 ;
repaint();

try
paintInfo.removeAllElements();
File filein = new File(openPicture.getDirectory(),openPicture.getFile());
picIn = new FileInputStream(filein);
VIn = new ObjectInputStream(picIn);
paintInfo = (Vector)VIn.readObject();
VIn.close();
repaint();
toolFlag = tempflag;



catch(ClassNotFoundException IOe2)

repaint();
toolFlag = tempflag;
System.out.println("can not read object");

catch(IOException IOe)

repaint();
toolFlag = tempflag;
System.out.println("can not read file");





if(e.getSource()==savePic)//保存图画

savePicture.setVisible(true);
try
File fileout = new File(savePicture.getDirectory(),savePicture.getFile());
picOut = new FileOutputStream(fileout);
VOut = new ObjectOutputStream(picOut);
VOut.writeObject(paintInfo);
VOut.close();

catch(IOException IOe)

System.out.println("can not write object");




//end paintboard

public class pb

public static void main(String args[])
new paintboard("画图程序");
参考技术A import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class HuaTu extends JPanel
implements MouseListener, MouseMotionListener, ActionListener

private JFrame f;
private int xBegin=0,yBegin=0,xEnd=0,yEnd=0;//开始和结束点坐标
private JButton butLine,butRect,butOval,butPen,butEraser;//线，方，圆，笔，橡皮
private JToolBar tb;
public HuaTu()

f = new JFrame("画图板");
butLine = new JButton("＼");
butRect = new JButton("□");
butOval = new JButton("○");
butPen = new JButton("Pen");
butEraser = new JButton("Eraser");
tb = new JToolBar();
tb.add(butLine);
tb.add(butRect);
tb.add(butOval);
tb.add(butPen);
tb.add(butEraser);
butLine.addActionListener(this);
butRect.addActionListener(this);
butOval.addActionListener(this);
butPen.addActionListener(this);
butEraser.addActionListener(this);
this.setLayout(new BorderLayout());
this.add(tb,BorderLayout.NORTH);
this.addMouseListener(this);
this.addMouseMotionListener(this);
f.add(this);
f.setBounds(100,100,600,500);
f.setVisible(true);


public void paintComponent(Graphics g)

//手工强制清空面板
super.paintComponent(g);
g.drawLine(xBegin,yBegin,xEnd,yEnd);


public static void main(String args[])

new HuaTu();

public void mouseClicked(MouseEvent e)


public void mousePressed(MouseEvent e)
//按下鼠标的时候，记录开始点的坐标
this.xBegin = e.getX();
this.yBegin = e.getY();

public void mouseReleased(MouseEvent e)



public void mouseDragged(MouseEvent e)
//记录拖动的时候的结束点
this.xEnd = e.getX();
this.yEnd = e.getY();
//每次拖动，都需要重绘面板，显示最的图形
this.repaint();

public void mouseEntered(MouseEvent e)


public void mouseExited(MouseEvent e)



public void mouseMoved(MouseEvent e)



/**
* Method actionPerformed
*
*
* @param e
*
*/
public void actionPerformed(ActionEvent e)
// TODO: Add your code here

参考技术B 这个上面有个，挺不错的，值得学习一下
http://hysun.itpub.net/post/5877/29678 参考技术C 我的博客里有一个:
http://hi.baidu.com/ttbet/blog/item/8260f4953c25220f7bf480a9.html 参考技术D 呵呵 兄弟 要代码 太直接了吧 最好自己先好好研究下子
实在解决不了 具体问题具体对待嘛