java畫圖板,java畫圖板程序實驗報告總結

本文目錄一覽：

• 1、JAVA編譯簡易畫圖板代碼
• 2、Java畫圖板問題請問為什麼我畫圖就會出現 thread “AWT-EventQueue-0” java.lang.NullPointerException
• 3、java 實現 簡單畫圖功能(簡單點的)
• 4、java 塗鴉畫板
• 5、JAVA實現簡單的畫圖板

JAVA編譯簡易畫圖板代碼

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;//畫筆大小

int Econ = 5;//橡皮大小

int toolFlag = 0;//toolFlag:工具標記

//toolFlag工具對應表：

//（0–畫筆）；（1–橡皮）；（2–清除）；

//（3–直線）；（4–圓）；（5–矩形）；

Color c = new Color(0,0,0); //畫筆顏色

BasicStroke size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);//畫筆粗細

Point cutflag = new Point(-1, -1, c, 6, con);//截斷標誌

Vector paintInfo = null;//點信息向量組

int n = 1;

FileInputStream picIn = null;

FileOutputStream picOut = null;

ObjectInputStream VIn = null;

ObjectOutputStream VOut = null;

// *工具面板–畫筆，直線，圓，矩形，多邊形,橡皮，清除*/

Panel toolPanel;

Button eraser, drLine,drCircle,drRect;

Button clear ,pen;

Choice ColChoice,SizeChoice,EraserChoice;

Button colchooser;

Label 顏色,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();

/*各工具按鈕及選擇項*/

//顏色選擇

ColChoice = new Choice();

ColChoice.add(“black”);

ColChoice.add(“red”);

ColChoice.add(“blue”);

ColChoice.add(“green”);

ColChoice.addItemListener(this);

//畫筆大小選擇

SizeChoice = new Choice();

SizeChoice.add(“1”);

SizeChoice.add(“3”);

SizeChoice.add(“5”);

SizeChoice.add(“7”);

SizeChoice.add(“9”);

SizeChoice.addItemListener(this);

//橡皮大小選擇

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(“畫筆”);

drLine = new Button(“畫直線”);

drCircle = new Button(“畫圓形”);

drRect = new Button(“畫矩形”);

openPic = new Button(“打開圖畫”);

savePic = new Button(“保存圖畫”);

colchooser = new Button(“顯示調色板”);

//各組件事件監聽

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);

顏色 = new Label(“畫筆顏色”,Label.CENTER);

大小B = new Label(“畫筆大小”,Label.CENTER);

大小E = new Label(“橡皮大小”,Label.CENTER);

//面板添加組件

toolPanel.add(openPic);

toolPanel.add(savePic);

toolPanel.add(pen);

toolPanel.add(drLine);

toolPanel.add(drCircle);

toolPanel.add(drRect);

toolPanel.add(顏色); 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,”打開圖畫”,FileDialog.LOAD);

openPicture.setVisible(false);

savePicture = new FileDialog(this,”保存圖畫”,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; in ;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://畫筆

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://畫直線

Line2D line2 = new Line2D.Double(p1.x, p1.y, p2.x, p2.y);

g2d.draw(line2);

break;

case 4://畫圓

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://畫矩形

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://截斷，跳過

i=i+1;

break;

default :

}//end switch

}//end if

}//end for

}

public void itemStateChanged(ItemEvent e)

{

if(e.getSource()==ColChoice)//預選顏色

{

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)//畫筆大小

{

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://畫筆

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://直線

x = (int)e.getX();

y = (int)e.getY();

p2 = new Point(x, y, c, toolFlag, con);

paintInfo.addElement(p2);

break;

case 4: //圓

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://畫筆

paintInfo.addElement(cutflag);

break;

case 1: //eraser

paintInfo.addElement(cutflag);

break;

case 3://直線

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: //圓

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)//畫筆

{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)//畫線

{toolFlag = 3;}

if(e.getSource()==drCircle)//畫圓

{toolFlag = 4;}

if(e.getSource()==drRect)//畫矩形

{toolFlag = 5;}

if(e.getSource()==colchooser)//調色板

{

Color newColor = JColorChooser.showDialog(this,”調色板”,c);

c = newColor;

}

if(e.getSource()==openPic)//打開圖畫

{

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)//保存圖畫

{

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(“畫圖程序”); }

}

Java畫圖板問題請問為什麼我畫圖就會出現 thread “AWT-EventQueue-0” java.lang.NullPointerException

錯誤是空指針異常，但是我java都很久沒玩了，看下你的循環呢，滑鼠監聽，設置標題

java 實現 簡單畫圖功能(簡單點的)

樓主給你一個我編的，直接保存成pb.java編譯運行，就是你要的畫圖功能

____________________________________________________________________

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;//畫筆大小

int Econ = 5;//橡皮大小

int toolFlag = 0;//toolFlag:工具標記

//toolFlag工具對應表：

//（0–畫筆）；（1–橡皮）；（2–清除）；

//（3–直線）；（4–圓）；（5–矩形）；

Color c = new Color(0,0,0); //畫筆顏色

BasicStroke size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);//畫筆粗細

Point cutflag = new Point(-1, -1, c, 6, con);//截斷標誌

Vector paintInfo = null;//點信息向量組

int n = 1;

FileInputStream picIn = null;

FileOutputStream picOut = null;

ObjectInputStream VIn = null;

ObjectOutputStream VOut = null;

// *工具面板–畫筆，直線，圓，矩形，多邊形,橡皮，清除*/

Panel toolPanel;

Button eraser, drLine,drCircle,drRect;

Button clear ,pen;

Choice ColChoice,SizeChoice,EraserChoice;

Button colchooser;

Label 顏色,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();

/*各工具按鈕及選擇項*/

//顏色選擇

ColChoice = new Choice();

ColChoice.add(“black”);

ColChoice.add(“red”);

ColChoice.add(“blue”);

ColChoice.add(“green”);

ColChoice.addItemListener(this);

//畫筆大小選擇

SizeChoice = new Choice();

SizeChoice.add(“1”);

SizeChoice.add(“3”);

SizeChoice.add(“5”);

SizeChoice.add(“7”);

SizeChoice.add(“9”);

SizeChoice.addItemListener(this);

//橡皮大小選擇

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(“畫筆”);

drLine = new Button(“畫直線”);

drCircle = new Button(“畫圓形”);

drRect = new Button(“畫矩形”);

openPic = new Button(“打開圖畫”);

savePic = new Button(“保存圖畫”);

colchooser = new Button(“顯示調色板”);

//各組件事件監聽

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);

顏色 = new Label(“畫筆顏色”,Label.CENTER);

大小B = new Label(“畫筆大小”,Label.CENTER);

大小E = new Label(“橡皮大小”,Label.CENTER);

//面板添加組件

toolPanel.add(openPic);

toolPanel.add(savePic);

toolPanel.add(pen);

toolPanel.add(drLine);

toolPanel.add(drCircle);

toolPanel.add(drRect);

toolPanel.add(顏色); 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,”打開圖畫”,FileDialog.LOAD);

openPicture.setVisible(false);

savePicture = new FileDialog(this,”保存圖畫”,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; in ;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://畫筆

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://畫直線

Line2D line2 = new Line2D.Double(p1.x, p1.y, p2.x, p2.y);

g2d.draw(line2);

break;

case 4://畫圓

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://畫矩形

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://截斷，跳過

i=i+1;

break;

default :

}//end switch

}//end if

}//end for

}

public void itemStateChanged(ItemEvent e)

{

if(e.getSource()==ColChoice)//預選顏色

{

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)//畫筆大小

{

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://畫筆

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://直線

x = (int)e.getX();

y = (int)e.getY();

p2 = new Point(x, y, c, toolFlag, con);

paintInfo.addElement(p2);

break;

case 4: //圓

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://畫筆

paintInfo.addElement(cutflag);

break;

case 1: //eraser

paintInfo.addElement(cutflag);

break;

case 3://直線

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: //圓

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)//畫筆

{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)//畫線

{toolFlag = 3;}

if(e.getSource()==drCircle)//畫圓

{toolFlag = 4;}

if(e.getSource()==drRect)//畫矩形

{toolFlag = 5;}

if(e.getSource()==colchooser)//調色板

{

Color newColor = JColorChooser.showDialog(this,”調色板”,c);

c = newColor;

}

if(e.getSource()==openPic)//打開圖畫

{

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)//保存圖畫

{

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(“畫圖程序”); }

}

java 塗鴉畫板

import java.awt.BasicStroke;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.FlowLayout;

import java.awt.Frame;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Label;

import java.awt.Panel;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.event.MouseMotionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

public class MouseDrawPanel extends Frame

{

private static final long serialVersionUID = 1L;

MouseEvent e = null;

int startX = -1;

int startY = -1;

int endX = -1;

int endY = -1;

boolean left = false;

public MouseDrawPanel ( String title )

{

setTitle (title);

setLayout (new BorderLayout ());

setResizable (false);

setSize (500, 400);

setLocationRelativeTo (null);

addWindowListener (new WindowAdapter ()

{

@Override

public void windowClosing ( WindowEvent e )

{

System.exit (0);

}

});

}

@Override

public void paintComponents ( Graphics g )

{

float lineWidth = 8.0f;

( (Graphics2D) g ).setStroke (new BasicStroke (lineWidth));

g.setColor (Color.YELLOW);

g.drawLine (startX, startY, endX, endY);

g.dispose ();

}

public static void main ( String[] args )

{

final MouseDrawPanel mdp = new MouseDrawPanel (“Use Mouse Draw”);

Panel panel = new Panel ();

panel.setLayout (new FlowLayout (FlowLayout.LEFT));

Label startL = new Label (“start: “);

Label endL = new Label (“end: “);

final Label nowL = new Label (“now: “);

final Label startR = new Label (“000,000”);

final Label endR = new Label (“000,000”);

final Label nowN = new Label (“000,000”);

panel.add (startL);

panel.add (startR);

panel.add (endL);

panel.add (endR);

panel.add (nowL);

panel.add (nowN);

mdp.add (panel, “South”);

mdp.addMouseMotionListener (new MouseMotionListener ()

{

@Override

public void mouseMoved ( MouseEvent e )

{

if (mdp.left)

{

nowN.setText (e.getX () + ” , ” + e.getY ());

}

}

@Override

public void mouseDragged ( MouseEvent e )

{

if (mdp.left)

{

mdp.endX = e.getX ();

mdp.endY = e.getY ();

mdp.paintComponents (mdp.getGraphics ());

mdp.startX = mdp.endX;

mdp.startY = mdp.endY;

endR.setText (mdp.endX + ” , ” + mdp.endY);

}

}

});

mdp.addMouseListener (new MouseAdapter ()

{

@Override

public void mousePressed ( MouseEvent e )

{

if (e.getButton () == MouseEvent.BUTTON1)

{

mdp.startX = e.getX ();

mdp.startY = e.getY ();

startR.setText (mdp.startX + ” , ” + mdp.startY);

mdp.left = true;

}

else

{

mdp.left = false;

}

}

@Override

public void mouseReleased ( MouseEvent e )

{

if (mdp.left)

{

endR.setText (e.getX () + ” , ” + e.getY ());

}

}

});

mdp.setVisible (true);

}

}

JAVA實現簡單的畫圖板

樓主寫一個html，很容易把下面代碼嵌入到applet，可以google一下實現，

還有copy自己不知道算不算複製。。。-_-!

——————————————————————–

樓主給你一個我的，直接保存成pb.java編譯運行，就是你要的畫圖功能 ，可以參考一下

____________________________________________________________________

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;//畫筆大小

int Econ = 5;//橡皮大小

int toolFlag = 0;//toolFlag:工具標記

//toolFlag工具對應表：

//（0–畫筆）；（1–橡皮）；（2–清除）；

//（3–直線）；（4–圓）；（5–矩形）；

Color c = new Color(0,0,0); //畫筆顏色

BasicStroke size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);//畫筆粗細

Point cutflag = new Point(-1, -1, c, 6, con);//截斷標誌

Vector paintInfo = null;//點信息向量組

int n = 1;

FileInputStream picIn = null;

FileOutputStream picOut = null;

ObjectInputStream VIn = null;

ObjectOutputStream VOut = null;

// *工具面板–畫筆，直線，圓，矩形，多邊形,橡皮，清除*/

Panel toolPanel;

Button eraser, drLine,drCircle,drRect;

Button clear ,pen;

Choice ColChoice,SizeChoice,EraserChoice;

Button colchooser;

Label 顏色,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();

/*各工具按鈕及選擇項*/

//顏色選擇

ColChoice = new Choice();

ColChoice.add(“black”);

ColChoice.add(“red”);

ColChoice.add(“blue”);

ColChoice.add(“green”);

ColChoice.addItemListener(this);

//畫筆大小選擇

SizeChoice = new Choice();

SizeChoice.add(“1”);

SizeChoice.add(“3”);

SizeChoice.add(“5”);

SizeChoice.add(“7”);

SizeChoice.add(“9”);

SizeChoice.addItemListener(this);

//橡皮大小選擇

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(“畫筆”);

drLine = new Button(“畫直線”);

drCircle = new Button(“畫圓形”);

drRect = new Button(“畫矩形”);

openPic = new Button(“打開圖畫”);

savePic = new Button(“保存圖畫”);

colchooser = new Button(“顯示調色板”);

//各組件事件監聽

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);

顏色 = new Label(“畫筆顏色”,Label.CENTER);

大小B = new Label(“畫筆大小”,Label.CENTER);

大小E = new Label(“橡皮大小”,Label.CENTER);

//面板添加組件

toolPanel.add(openPic);

toolPanel.add(savePic);

toolPanel.add(pen);

toolPanel.add(drLine);

toolPanel.add(drCircle);

toolPanel.add(drRect);

toolPanel.add(顏色); 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,”打開圖畫”,FileDialog.LOAD);

openPicture.setVisible(false);

savePicture = new FileDialog(this,”保存圖畫”,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; in ;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://畫筆

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://畫直線

Line2D line2 = new Line2D.Double(p1.x, p1.y, p2.x, p2.y);

g2d.draw(line2);

break;

case 4://畫圓

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://畫矩形

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://截斷，跳過

i=i+1;

break;

default :

}//end switch

}//end if

}//end for

}

public void itemStateChanged(ItemEvent e)

{

if(e.getSource()==ColChoice)//預選顏色

{

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)//畫筆大小

{

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://畫筆

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://直線

x = (int)e.getX();

y = (int)e.getY();

p2 = new Point(x, y, c, toolFlag, con);

paintInfo.addElement(p2);

break;

case 4: //圓

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://畫筆

paintInfo.addElement(cutflag);

break;

case 1: //eraser

paintInfo.addElement(cutflag);

break;

case 3://直線

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: //圓

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)//畫筆

{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)//畫線

{toolFlag = 3;}

if(e.getSource()==drCircle)//畫圓

{toolFlag = 4;}

if(e.getSource()==drRect)//畫矩形

{toolFlag = 5;}

if(e.getSource()==colchooser)//調色板

{

Color newColor = JColorChooser.showDialog(this,”調色板”,c);

c = newColor;

}

if(e.getSource()==openPic)//打開圖畫

{

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)//保存圖畫

{

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(“畫圖程序”); }

}