CALayer *middleBorder = [CALayer layer];middleBorder.frame = CGRectMake(x, y, width, height);middleBorder.backgroundColor = UIColor.CGColor;[myView.layer addSublayer:middleBorder];

 1 - (void)drawLineWithPoint:(CGPoint) startPoint toPoint:(CGPoint)toPoint 2 { 3         CGSize screenSize = [[UIScreen mainScreen] applicationFrame].size; 4              5         UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, screenSize.width, screenSize.height)]; 6         //    UIImageView *imageView = [[UIImageView alloc] init]; 7         //    imageView.frame = self.contentView.frame; 8         [self.contentView addSubview:imageView]; 9             10         UIGraphicsBeginImageContext(imageView.frame.size);11         [imageView.image drawInRect:CGRectMake(0, 0, imageView.frame.size.width, imageView.frame.size.height)];12             13         //获得处理的上下文14         CGContextRef context = UIGraphicsGetCurrentContext();15             16         //指定直线样式17         CGContextSetLineCap(context, kCGLineCapSquare);18             19         //直线宽度20         CGContextSetLineWidth(context, 1.0);21             22         //设置颜色23         // red:166/255.0 green:177/255.0 blue:186/255.024         CGContextSetRGBStrokeColor(context, 246.0/255.0, 247.0/255.0, 247.0/255.0, 1.0);25             26         //开始绘制27         CGContextBeginPath(context);28             29         //画笔移动到点(31,170)30         CGContextMoveToPoint(context, startPoint.x, startPoint.y);31             32         //下一点33         CGContextAddLineToPoint(context, toPoint.x, toPoint.y);34             35         //绘制完成36         CGContextStrokePath(context);37             38         imageView.image = UIGraphicsGetImageFromCurrentImageContext();39         UIGraphicsEndImageContext();40             41         //    NSLog(@"%f, %f", imageView.frame.size.width, imageView.frame.size.height);42 }