找到导航栏下面灰线

- (UIImageView *)findHairlineImageViewUnder:(UIView *)view

{

if ([view isKindOfClass:UIImageView.class] && view.bounds.size.height <= 1.0)

{

return (UIImageView *)view;

}

for (UIView *subview in view.subviews)

{

UIImageView *imageView = [self findHairlineImageViewUnder:subview];

if (imageView)

{

return imageView;

}

}

return nil;

}