java 画图板 windows画图板简单实现

//import java.applet.Applet; import java.awt.*; import java.awt.event.*; import java.awt.geom.*; import javax.swing.*; public class mouseTopaint extends JFrame implements MouseMotionListener { private int x,y; /*private JButton jb1=new JButton("红 色"); private JButton jb2=new JButton("绿 色"); private JButton jb3=new JButton("灰 色"); private JButton jb4=new JButton("蓝 色"); private JButton jb5=new JButton("黑 色"); private JButton jb6=new JButton("黄 色");*/ mouseTopaint(){ setVisible(true); /*Container cp=getContentPane(); JPanel p1=new JPanel(); JPanel p2=new JPanel(); JButton l1=new JButton("请选择绘图颜色"); p1.setSize(200, 400); p2.setSize(300, 400); p1.setLayout(new GridLayout(3,2)); p1.add(jb1); p1.add(jb2); p1.add(jb3); p1.add(jb4); p1.add(jb5); p1.add(jb6); //p1.add(l1); JSplitPane sp1=new JSplitPane(1,true,p1,p2); cp.add(sp1);*/ //setBackground(Color.pink); JButton l1=new JButton("请选择绘图颜色"); //jf=new JFrame(""); Color color; add(l1); // l1.addActionListener(this); //color=JColorChooser.showDialog(jf, "请选择背景颜色", Color.BLUE); setCursor(Cursor.getPredefinedCursor(12)); addMouseMotionListener(this); } public static void main(String[] args){ mouseTopaint frm=new mouseTopaint(); //frm.setBackground(Color.pink); //frm.setCursor(Cursor.getPredefinedCursor(12)); //frm.pack(); frm.setSize(500, 400); frm.setLocationRelativeTo(null); frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frm.setResizable(false); //窗口不可变动 } /*public void mousepaint(){ setBackground(Color.pink); setCursor(Cursor.getPredefinedCursor(12)); addMouseMotionListener(this); }*/ public void paint(Graphics g){ Graphics2D g2d=(Graphics2D)g; /*l1.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e){ g2d.setColor(Color.red); } });*/ //color=JColorChooser.showDialog(jf, "请选择背景颜色", Color.BLUE); Color color; //g2d.setColor(color); //g.setColor(Color.red); BasicStroke bs1=new BasicStroke(10); g2d.setStroke(bs1); //get(bs1); Line2D li=new Line2D.Double(x,y,x,y); g2d.draw(li); //g.drawLine(x, y, x, y); } public void update(Graphics g){ paint(g); } public void mouseDragged(MouseEvent e){ x=(int)e.getX(); y=(int)e.getY(); repaint(); } public void mouseMoved(MouseEvent e){ } } /*public class mouseTopaint extends Applet implements MouseMotionListener { int x,y; public mouseTopaint(){ setBackground(Color.pink); setCursor(Cursor.getPredefinedCursor(12)); addMouseMotionListener(this); } public void paint(Graphics g){ Graphics2D g2d=(Graphics2D)g; g2d.setColor(Color.red); BasicStroke bs1=new BasicStroke(10); g2d.setStroke(bs1); Line2D li=new Line2D.Double(x,y,x,y); g2d.draw(li); } public void update(Graphics g){ paint(g); } public void mouseDragged(MouseEvent e){ x=(int)e.getX(); y=(int)e.getY(); repaint(); } public void mouseMoved(MouseEvent e){ } }*/