兄弟帮下忙！感激不尽！JAVA2D绘图中怎么实现画的图象被选中?还有实现图象的移动?

找了一个java的画图程序，希望有帮助；/*
* 画图程序  来自bc-cn论坛
* java applet  与windows自带的程序类似，功能简单
*
*
*/
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.util.Iterator;
import java.util.LinkedList;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Test extends JPanel implements Runnable,ActionListener,MouseListener,MouseMotionListener {

private JButton clear,draw,replay,btnColor;//清除,开始画和重放和颜色的按钮
    Color choosedColor = Color.BLACK;//选中的颜色
    JDialog dialog = null;
    private LinkedList<MyShape> save;//保存起来的形状

    private int flag=0;//定义一个标志,用它来传递当前是在干什么
    private final int DRAW=1;//1代表当前正在画图
    private final int REPLAY=2;//2代表当前正在重放

    private LinkedList<Pen> ps;//保存点

    private volatile boolean go;
    /** Creates a new instance of Test */

    public Test() {
        initOther();
        initWindow();
    }

    private void initOther(){
        clear=new JButton("清除");
        draw=new JButton("开始画");
        replay=new JButton("重放");
        btnColor = new JButton("选取颜色");//选颜色

        clear.addActionListener(this);
        draw.addActionListener(this);
        replay.addActionListener(this);

        save=new LinkedList<MyShape>();
        ps=new LinkedList<Pen>();
        clear.setEnabled(false);
        replay.setEnabled(false);
    }
    private void initWindow(){
        JFrame jf=new JFrame("画板 Dream ");
        JPanel down=new JPanel();
        down.add(clear);
        down.add(draw);
        down.add(replay);
        down.add(btnColor);
        this.setBorder(BorderFactory.createTitledBorder("绘画区"));
        jf.add(this,BorderLayout.CENTER);
        jf.add(down,BorderLayout.SOUTH);
        jf.setSize(500,450);
        jf.setLocationRelativeTo(null);
        jf.setVisible(true);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        btnColor.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                final JColorChooser chooser = new JColorChooser();
                dialog = JColorChooser.createDialog(null, "选取颜色", false, chooser, new ActionListener()
                {
                    public void actionPerformed(ActionEvent e)
                    {
                        choosedColor = chooser.getColor();
                    }
                }, null);
                dialog.setVisible(true);
            }
        });
    }

    protected void paintComponent(Graphics g){
        super.paintComponent(g);
        if(flag==DRAW){
            for(MyShape my:save){
                my.drawMe(g);
            }
            Point previous=null;
            for(Pen pp:ps){
                Point p = pp.getP();
                if(previous!=null)
                {
                    Graphics2D g2 = (Graphics2D)g;
                    g2.setStroke(new BasicStroke(2,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL,2));
                    g.setColor(pp.getColor());
                    g.drawLine(previous.x,previous.y,p.x,p.y);
                }
                previous=p;
            }
        }else if(flag==REPLAY){
            try{
                for(MyShape my:save){
                    if(my.hasNext()){
                        my.drawNext(g);
                        return;
                    }else{
                        my.drawMe(g);
                    }
                }

                for(MyShape my:save)
               {
                    my.reset();
                }
                go=false;
                replay.setEnabled(true);
                draw.setEnabled(true);
            } catch(Exception exe){
                exe.printStackTrace();
            }
        }
    }

    public void run(){
        while(go){
            try{
                Thread.sleep(20);
                repaint();
            } catch(Exception exe){
                exe.printStackTrace();
            }
        }
        flag=DRAW;
        repaint();
    }

    public void actionPerformed(ActionEvent e) {
        Object source=e.getSource();
        if(source==clear){
            save.clear();
            replay.setEnabled(false);
            repaint();
        }else if(source==draw){
            flag=DRAW;
            this.addMouseListener(this);
            this.addMouseMotionListener(this);
            draw.setEnabled(false);
            clear.setEnabled(true);
        }else if(source==replay){
            flag=REPLAY;
            this.removeMouseListener(this);
            this.removeMouseMotionListener(this);
            replay.setEnabled(false);
            draw.setEnabled(false);
            clear.setEnabled(false);
            go=true;
            new Thread(this).start();
        }
    }
    public void mouseClicked(MouseEvent e) {
    }

    public void mousePressed(MouseEvent e) {
        Point p=e.getPoint();
        Pen pp = new Pen(p,choosedColor);
        replay.setEnabled(false);
        ps.offer(pp);
        repaint();
    }

    public void mouseReleased(MouseEvent e) {
        replay.setEnabled(true);
        Pen pp = new Pen(e.getPoint(),choosedColor);
        save.add(new MyLine(ps));
        ps=new LinkedList<Pen>();
        repaint();
    }

    public void mouseEntered(MouseEvent e) {
    }

    public void mouseExited(MouseEvent e) {
    }

    public void mouseDragged(MouseEvent e) {
        Pen pp = new Pen(e.getPoint(),choosedColor);
        ps.offer(pp);
        repaint();
    }

    public void mouseMoved(MouseEvent e) {
    }

    public static void main(String[] args) {
        new Test();
    }
}

继续//定义了一个接口,它规定了重绘自己的方法
interface MyShape{
    void drawMe(Graphics g);//一下子画出自己
    boolean hasNext();//是否还有下一个状态
    void drawNext(Graphics g);//画出自己下一个样子
    void reset();//重置一下
}class Pen
{
    private Point p;
    private Color color;
    Pen(Point p,Color color)
    {
        this.p = p;
        this.color = color;
    }
    public Color getColor() {
        return color;
    }
    public void setColor(Color color) {
        this.color = color;
    }
    public Point getP() {
        return p;
    }
    public void setP(Point p) {
        this.p = p;
    }

}class MyLine implements MyShape{

    private LinkedList<Pen> ll;//用来保存点
    private Iterator<Pen> it;//一个迭代器
    private LinkedList<Pen> over;//保存已经画过的点

    public MyLine(LinkedList<Pen> ll){
        this.ll=ll;
        it=ll.iterator();
        over=new LinkedList<Pen>();
    }

    public void drawMe(Graphics g)
    {
        Point previous=ll.getFirst().getP();
        for(Pen pp:ll){
            Point p = pp.getP();
            Graphics2D g2 = (Graphics2D)g;
            g2.setStroke(new BasicStroke(2,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL,2));
            g.setColor(pp.getColor());
            g.drawLine(previous.x,previous.y,p.x,p.y);
            previous=p;
        }
    }

    public boolean hasNext() {
        return it.hasNext();
    }

    public void drawNext(Graphics g)
    {
        over.add(it.next());
        Point previous=over.getFirst().getP();
        for(Pen pp:over){
            Point p = pp.getP();
            Graphics2D g2 = (Graphics2D)g;
            g2.setStroke(new BasicStroke(2,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL,2));
            g.setColor(pp.getColor());
            g.drawLine(previous.x,previous.y,p.x,p.y);
            previous=p;
        }
    }

    public void reset(){
        it=ll.iterator();
        over.clear();
    }
}

sunny3106(),那个my:save是什么意思啊？“：”这个字符是表达什么？有没人知道？

for(MyShape my:save){
                my.drawMe(g);
}
for增强版与for-each相同功能，上面代码可以改为：
for(int i=0;i<save.size();i++){
    MyShape my = save.get(i);
    my.drawMe(g);
}

private LinkedList<MyShape> save;怎么编译错误的？

LinkedList<MyShape>：泛型（也有叫模板的），需要1.5或以上的JDK支持

如果是1.5以下版本的，private LinkedList<MyShape> save;这个需要怎么编译呢？

把<MyShape>去掉，但是後面很多地方都要進行“拆箱”，foreach也不可以再用了，比較麻煩。
還是升級JDK吧，可以多學不少東西的。

调试易

兄弟帮下忙！感激不尽！JAVA2D绘图中怎么实现画的图象被选中?还有实现图象的移动?

解决方案 »