// ****************动作监听器的方法*********************//
    public void actionPerformed(ActionEvent e) {
    String str = e.getActionCommand();      
       if ("颜色".equals(str)) {
            color = javax.swing.JColorChooser.showDialog(null, "请选择颜色", java.awt.Color.BLACK);
              B = color.getBlue();         
              R = color.getRed();            
              G = color.getGreen();
            }
        }

    // **************鼠标监听器的方法*************//   
      public void mousePressed(MouseEvent e) {
    // 设置画布颜色      
      g.setColor(color);      
   // 得到选中的按钮的动作命令        
       shape = group.getSelection().getActionCommand();  
       System.out.println(shape);
     if ("直线".equals(shape)) {      
          // 画直线            
    g.drawLine(x1, y1, x2, y2);        
         MyLine li = new MyLine(x1, y1, x2, y2,R,G,B);       //  问一下，怎么把上面得到的R,G,B传入这个函数
         l.add(li);         
   }