功能包括：鼠标控制画直线，矩形，椭圆；设置画笔颜色，线形，宽度；线形包括实线，虚线，点线，点划线，双点划线。-Features include: mouse control, painting a straight line, rectangle, ellipse set brush color, line width linear including the solid line, dotted line, points, lines, points, lines, double-poin