隐藏导航栏下的1px底部横线

摘要: 原理是，直接用一个UIImageView（默认颜色为透明）代替了原来的横线

第一种：

先设置一个全局变量 UIImageView * imageView;

然后：

- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
_imageView.hidden = YES;
}

- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
_imageView.hidden = NO;
}

- (void)viewDidLoad
{
[super viewDidLoad];

_imageView = [self findHairlineImageViewUnder:self.navigationController.navigationBar];
}

- (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;
}

第二种：

直接在AppDelegate.m中设置，可全局生效

[[UINavigationBar appearance] setBackgroundImage:[[UIImage alloc] init] forBarPosition:UIBarPositionAny barMetrics:UIBarMetricsDefault];
[[UINavigationBar appearance] setShadowImage:[[UIImage alloc] init]];