ios显示或隐藏导航栏的底线

根据产品需求要求把这个界面导航栏的底线去掉,下个控制器还需要有底线.

使用下面的代码实现

//在页面出现的时候就将黑线隐藏起来

-(void)viewWillAppear:(BOOL)animated

{

[self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];

[self.navigationController.navigationBar setShadowImage:[UIImage new]];

_navBarHairlineImageView.hidden = YES;

}

//在页面消失的时候就让navigationbar还原样式

-(void)viewWillDisappear:(BOOL)animated{

[self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];

[self.navigationController.navigationBar setShadowImage:nil];

//再定义一个imageview来等同于这个黑线

//UIImageView *navBarHairlineImageView;

_navBarHairlineImageView = [self findHairlineImageViewUnder:self.navigationController.navigationBar];

}

//这个方法唯一的不好就是会影响导航栏的translucent(透明)属性

//方法2:找出黑线,再做处理:

//通过一个方法来找到这个黑线(findHairlineImageViewUnder):

- (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;

}

////同样的在界面出现时候开启隐藏

//-(void)viewWillAppear:(BOOL)animated

//{

//    _navBarHairlineImageView.hidden = YES;

//}

////在页面消失的时候就让出现

-(void)viewDidAppear:(BOOL)animated

{

_navBarHairlineImageView.hidden = NO;

}