对图形绘制程序的修改完善,里面除了包含圆,矩形,直线等矢量图形的绘制保存,里面还包含图形的操作,如拖动,旋转.还增加了图形的放大缩小,填充,撤销和重做机制等功能.-Graphics drawing program for the revised and improved, which contains apart from a round, rectangular, straight-line drawing vector graphics, such as preservation, whic