请教如何在java画图中不覆盖原来的画图？？？

发布网友发布时间：2023-10-26 16:30

共1个回答

热心网友时间：2024-11-25 09:56

import java.awt.BorderLayout; import java.awt.Button; import java.awt.Color; import java.awt.Container; import java.awt.Graphics; import java.awt.Panel; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.awt.event.MouseMotionAdapter; import java.awt.event.MouseMotionListener; import javax.swing.ButtonGroup; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.UIManager; //import javax.swing.Component;publicclass ShapeMain extends JFrame implements ActionListener,MouseListener,MouseMotionListener{ int x,y,x1,y1,x2,y2,width,height; boolean isFirstPoint = true; //初始化开始画的是线int drawType = PaintingGround.LINE; //初始化开始不是填充boolean isFill = false; //添加控件 ButtonGroup btg = new ButtonGroup(); Button btLine = new Button("线"); Button btRectangle = new Button("矩形"); Button btRound = new Button("圆"); Button btEllipse = new Button("椭圆"); Button tbFillState = new Button("填充"); Button button3 = new Button("文本操作"); Button button2 = new Button("清除"); Button button1 = new Button("选择颜色"); Panel buttonPanel = new Panel(); PaintingGround paintingGround = new PaintingGround(); //Main Methodpublicstaticvoid main(String[] args) { //设置显示外观try{ UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); }catch(Exception e) { e.printStackTrace(); } new ShapeMain(); } //构造函数public ShapeMain() { //控件添加到控件组中 // btg.add(btLine); // btg.add(btRectangle); // btg.add(btRound); // btg.add(btEllipse); buttonPanel.add(btLine); buttonPanel.add(btRectangle); buttonPanel.add(btRound); buttonPanel.add(btEllipse); buttonPanel.add(tbFillState); //设置容器及容器的整体布局 Container cp = this; cp.setLayout(new BorderLayout()); cp.add(BorderLayout.NORTH,buttonPanel); cp.add(BorderLayout.CENTER,paintingGround); //cp.add(BorderLayout.SOUTH,jf); //jf.setJMenuBar(mb); setLocation(300,150); setSize(600,480); setVisible(true); setDefaultCloseOperation(EXIT_ON_CLOSE); //添加鼠标触发事件 paintingGround.addMouseListener(new MouseAdapter() { publicvoid mouseReleased(MouseEvent evn) { isFirstPoint = true; } }); //对鼠标的输入进行判断并调用画图程序 paintingGround.addMouseMotionListener(new MouseMotionAdapter() { publicvoid mouseDragged(MouseEvent evn) { if(isFirstPoint) { x1 = evn.getX(); y1 = evn.getY(); isFirstPoint = false; } else { x2 = evn.getX(); y2 = evn.getY(); switch(drawType) { case PaintingGround.LINE: //画线paintingGround.drawLine(x1,y1,x2,y2); break; case PaintingGround.RECTANGLE: //画矫形 paintingGround.drawRect(x1,y1,x2-x1,y2-y1); break; case PaintingGround.ROUND: //画圆//两点距离公式int size = Math.abs((int)Math.sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1))); paintingGround.drawRound(x1,y1,size); break; case PaintingGround.ELLIPSE: //画椭圆 paintingGround.drawEllipse(x1,y1,x2-x1,y2-y1); break; default: break; } } } }); //各个控件的触发事件 btLine.addActionListener(new ActionListener(){ publicvoid actionPerformed(ActionEvent evn) { drawType = PaintingGround.LINE; } }); btRectangle.addActionListener(new ActionListener(){ publicvoid actionPerformed(ActionEvent evn) { drawType = PaintingGround.RECTANGLE; } }); btRound.addActionListener(new ActionListener(){ publicvoid actionPerformed(ActionEvent evn) { drawType = PaintingGround.ROUND; } }); btEllipse.addActionListener(new ActionListener(){ publicvoid actionPerformed(ActionEvent evn) { drawType = PaintingGround.ELLIPSE; } }); tbFillState.addActionListener(new ActionListener(){ publicvoid actionPerformed(ActionEvent evn) { isFill = tbFillState.isShowing(); paintingGround.setFillState(isFill); } }); } publicvoid actionPerformed(ActionEvent e) { // TODO Auto-generated method stub } publicvoid mouseClicked(MouseEvent e) { // TODO Auto-generated method stub } publicvoid mousePressed(MouseEvent e) { // TODO Auto-generated method stub } publicvoid mouseReleased(MouseEvent e) { // TODO Auto-generated method stub } publicvoid mouseEntered(MouseEvent e) { // TODO Auto-generated method stub } publicvoid mouseExited(MouseEvent e) { // TODO Auto-generated method stub } publicvoid mouseDragged(MouseEvent e) { // TODO Auto-generated method stub } publicvoid mouseMoved(MouseEvent e) { // TODO Auto-generated method stub } } class PaintingGround extends JPanel { publicstaticfinalint LINE = 1; publicstaticfinalint RECTANGLE = 2; publicstaticfinalint ROUND = 3; publicstaticfinalint ELLIPSE = 4; privateint x,y; privateint x1,y1,x2,y2; privateint width, height,size; privateint drawType = 0; privateboolean isFill = false; //构造函数public PaintingGround() { setBackground(Color.white); } //判断是用实心还是空心的,publicvoid paint(Graphics g) { //super.paintComponent(g); //super.paint(g);super.paint(g); g.setColor(Color.black); if(isFill) { switch(drawType) { case LINE: g.drawLine(x1,y1,x2,y2); break; case RECTANGLE: g.fillRect(x,y,width,height); break; case ROUND: g.fillOval(x,y,size,size); break; case ELLIPSE: g.fillOval(x,y,width,height); break; default: break; } } else { switch(drawType) { case LINE: g.drawLine(x1,y1,x2,y2); break; case RECTANGLE: g.drawRect(x,y,width,height); break; case ROUND: g.drawOval(x,y,size,size); break; case ELLIPSE: g.drawOval(x,y,width,height); break; default: break; } } } publicvoid drawLine(int x1, int y1, int x2,int y2) { this.x1 = x1; this.y1 = y1; this.x2 = x2; this.y2 = y2; drawType = LINE; //jim isFill = false; //jimrepaint(); } //具体的实现方式publicvoid drawRect(int x,int y,int width, int height) { this.x = x; this.y = y; this.width = width; this.height = height; drawType = RECTANGLE; repaint(); } publicvoid drawRound(int x,int y,int size) { this.x = x; this.y = y; this.size = size; drawType = ROUND; repaint(); } publicvoid drawEllipse(int x,int y,int width,int height) { this.x = x; this.y = y; this.width = width; this.height = height; drawType = ELLIPSE; repaint(); } publicvoid setFillState(boolean isFill) { this.isFill = isFill; } }