做一个用鼠标绘图的java程序_软件运维

开四个变量currentX,

currentY,

previousX,

previousY,

把每次鼠标所在点存在变量currentX,

currentY中，下一次存的时候就把currentX和currentY的值放到previousX和previousY中，这样就能方便的访问倒数第二个点的坐标了。

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=0i<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")}

}

public enum ShapeTypes {

LINE, CIRCLE, RECTANGLE

} public interface Shape {

void paint(Graphics g)

} public class Rectangle implements Shape {

// 矩形左上角的坐标

private int x, y

// 矩形的宽度和高度

private int width, height

private Color rectangleColor

public Rectangle() {

super()

}

public Rectangle(int x, int y, int width, int height, Color rectangleColor) {

super()

this.x = x

this.y = y

this.width = width

this.height = height

this.rectangleColor = rectangleColor

}

@Override

public void paint(Graphics g) {

g.setColor(rectangleColor)

g.drawRect(x, y, width, height)

}

} public class Line implements Shape {

// 直线的起始位置

private int x1, y1

// 直线的终止位置

private int x2, y2

private Color lineColor

public Line(int x1, int y1, int x2, int y2, Color lineColor) {

super()

this.x1 = x1

this.y1 = y1

this.x2 = x2

this.y2 = y2

this.lineColor = lineColor

}

public Line() {

super()

}

@Override

public void paint(Graphics g) {

g.setColor(lineColor)

g.drawLine(x1, y1, x2, y2)

}

} public class Circle implements Shape {

// 圆的颜色

private Color circleColor

// 圆心的坐标

private int x, y

// 圆的半径

private int radius

public Circle() {

super()

}

public Circle(int x, int y, int radius, Color circleColor) {

super()

this.circleColor = circleColor

this.x = x

this.y = y

this.radius = radius

}

@Override

public void paint(Graphics g) {

g.setColor(circleColor)

// 画弧, 当弧的宽度和高度一致且从0~360度时就是原形了

g.drawArc(x, y, radius, radius, 0, 360)

}

} public class SketchpadPanel extends Canvas implements MouseListener, MouseMotionListener {

private static final long serialVersionUID = -5229161042153132522L

// 鼠标点击起始坐标和当前坐标

private int beginX = 0, beginY = 0, currentX = 0, currentY = 0

// 判断鼠标是否被按下

private boolean isMousePressing = false

// 保存当前的图形, 在撤销和恢复时使用

private final Stack<Shape> currentShapes = new Stack<Shape>()

// 保存已经删除过的图形

private final Stack<Shape> deletedShapes = new Stack<Shape>()

private ShapeTypes type

private Color color

public SketchpadPanel() {

addMouseListener(this)

addMouseMotionListener(this)

}

/**

* 撤销方法

public void undo() {

if (currentShapes.size() > 0) {

// 从所有保存过的图形中取出最后一个, 放入到已删除的图形中去

Shape shape = currentShapes.pop()

deletedShapes.push(shape)

repaint()

}

/**

* 恢复撤销方法

public void redo() {

if (deletedShapes.size() > 0) {

// 从所有删除的图形中取出最后一个, 放入保存的图形中

Shape shape = deletedShapes.pop()

currentShapes.push(shape)

repaint()

}

/**

* 设置命令

* @param type

public void setShapeType(ShapeTypes type) {

this.type = type

}

/**

* 设置颜色

* @param color

public void setColor(Color color) {

this.color = color

}

public void updete(Graphics g) {

paint(g)

}

/**

* 绘制画板

@Override

public void paint(Graphics g) {

// 绘制画板

Dimension size = getSize()

int width = size.width

int height = size.height

g.setColor(Color.WHITE)

g.fillRect(0, 0, width, height)

// 绘制所有图形

Shape shape = null

Enumeration<Shape> e = currentShapes.elements()

while (e.hasMoreElements()) {

shape = e.nextElement()

shape.paint(g)

}

// 如果当前鼠标没有释放

if (isMousePressing) {

g.setColor(color)

switch (type) {

// 绘制直线

case LINE:

g.drawLine(beginX, beginY, currentX, currentY)

break

// 绘制矩形

case RECTANGLE:

if (currentX < beginX) {

if (currentY < beginY) {

// 如果当前位置在起始位置的左上方, 则以鼠标当前位置为矩形的左上角位置

g.drawRect(currentX, currentY, beginX - currentX, beginY - currentY)

} else {

// 如果当前位置在起始位置的左下方, 则以鼠标当前位置的横坐标和起始位置的纵坐标作为矩形的左上角位置

g.drawRect(currentX, beginY, beginX - currentX, currentY - beginY)

}

} else {

if (currentY < beginY) {

// 如果当前位置在起始位置的右上方, 则以鼠标起始位置的很坐标和当前位置的纵坐标作为矩形的左上角位置

g.drawRect(beginX, currentY, currentX - beginX, beginY - currentY)

} else {

// 如果当前位置在起始位置的右下方, 则已起始位置作为矩形的左上叫位置

g.drawRect(beginX, beginY, currentX - beginX, currentY - beginY)

}

break

// 绘制圆形

case CIRCLE:

// 半径为a*a + b*b的平方根

int radius = (int) Math

.sqrt((beginX - currentX) * (beginX - currentX) + (beginY - currentY) * (beginY - currentY))

g.drawArc(beginX - radius / 2, beginY - radius / 2, radius, radius, 0, 360)

break

}

@Override

public void mouseClicked(MouseEvent e) {

}

@Override

public void mouseEntered(MouseEvent e) {

}

@Override

public void mouseExited(MouseEvent e) {

}

/**

* 当鼠标按下的时候获得起始坐标

@Override

public void mousePressed(MouseEvent e) {

beginX = e.getX()

beginY = e.getY()

isMousePressing = true

}

/**

* 当鼠标释放时获得当前坐标

@Override

public void mouseReleased(MouseEvent e) {

currentX = e.getX()

currentY = e.getY()

isMousePressing = false

// 当释放鼠标时, 将绘制的图形保存到shapes中

switch (type) {

// 绘制直线

case LINE:

Line line = new Line(beginX, beginY, currentX, currentY, color)

currentShapes.push(line)

break

// 绘制圆形

case CIRCLE:

// 半径为a*a + b*b的平方根

int radius = (int) Math

.sqrt((beginX - currentX) * (beginX - currentX) + (beginY - currentY) * (beginY - currentY))

Circle circle = new Circle(beginX - radius / 2, beginY - radius / 2, radius, color)

currentShapes.push(circle)

break

// 绘制矩形

case RECTANGLE:

Rectangle rectangle = null

if (currentX < beginX) {

if (currentY < beginY) {

rectangle = new Rectangle(currentX, currentY, beginX - currentX, beginY - currentY, color)

} else {

rectangle = new Rectangle(currentX, beginY, beginX - currentX, currentY - beginY, color)

}

} else {

if (currentY < beginY) {

rectangle = new Rectangle(beginX, currentY, currentX - beginX, beginY - currentY, color)

} else {

rectangle = new Rectangle(beginX, beginY, currentX - beginX, currentY - beginY, color)

}

currentShapes.push(rectangle)

break

}

repaint()

}

@Override

public void mouseDragged(MouseEvent e) {

currentX = e.getX()

currentY = e.getY()

this.repaint()

}

@Override

public void mouseMoved(MouseEvent e) {

}

} public class SketchpadFrame extends JFrame {

private static final long serialVersionUID = -7080053971741609904L

private final JPanel commandPanel = new JPanel() // 存放命令的面板

private final JPanel colorPanel = new JPanel() // 存放颜色的面板

private final JPanel mainPanel = new JPanel() // 主面板

private final JButton redButton = new JButton("红色")

private final JButton blueButton = new JButton("蓝色")

private final JButton greenButton = new JButton("绿色")

private final JButton lineButton = new JButton("直线")

private final JButton circleButton = new JButton("圆")

private final JButton rectangleButton = new JButton("矩形")

private final JButton undoButton = new JButton("撤销")

private final JButton redoButton = new JButton("恢复撤销")

private final JButton exitButton = new JButton("退出")

SketchpadPanel sketchPanel = new SketchpadPanel()

private void initFrame() {

commandPanel.setLayout(new FlowLayout())

commandPanel.add(lineButton)

commandPanel.add(circleButton)

commandPanel.add(rectangleButton)

commandPanel.add(undoButton)

commandPanel.add(redoButton)

commandPanel.add(exitButton)

colorPanel.setLayout(new FlowLayout())

colorPanel.add(redButton)

colorPanel.add(blueButton)

colorPanel.add(greenButton)

mainPanel.setLayout(new BorderLayout())

mainPanel.add(commandPanel, BorderLayout.NORTH)

mainPanel.add(colorPanel, BorderLayout.CENTER)

getContentPane().add("South", mainPanel)

getContentPane().add("Center", sketchPanel)

// 初始化设置:颜色和命令

lineButton.setForeground(Color.RED)

sketchPanel.setColor(Color.RED)

redButton.setForeground(Color.RED)

sketchPanel.setShapeType(ShapeTypes.LINE)

}

private void initListener() {

redButton.addActionListener(new ActionListener() {

@Override