ios触摸画图生成五角星

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{ UITouch * touch=[touches anyObject]; currentPoint =[touch locationInView:self]; UIGraphicsBeginImageContext(self.frame.size); CGContextRef ref=UIGraphicsGetCurrentContext(); [drewImage.image drawInRect:CGRectMake(0, 0, drewImage.frame.size.width, drewImage.frame.size.height)]; CGContextSetLineCap(ref,kCGLineCapSquare); CGContextSetLineJoin(ref, kCGLineJoinRound); 实用触摸事件，利用画图设置画笔颜色，长度，填充 生成五角星，