iOS navigationBar导航栏底部与self.view的分界线的隐藏

• ios开发中经常碰到各种需求，比如要求导航栏的颜色和self.view的颜色一样，当我们直接设置navigationBar的颜色和view一样时，我们会发现navigationBar还会有一条分割线留下，本文就是介绍怎么隐藏导航栏底部的分割线的。

• 第一种方法：不会影响导航栏translucent 半透明的显示

• 首先在viewDidLoad 定义一个 UIImageView *navigationImageView 来存储底部分割线。

UIImageView *navigationImageView = [self findHairlineImageViewUnder:self.navigationController.navigationBar];
self.navigationImageView = navigationImageView;

-(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;
}

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

-(void)viewDidDisappear:(BOOL)animated {
 [super viewDidDisappear:animated]; self.navigationImageView.hidden = NO;
}

• 第二种方法：会删除导航栏 translucent 半透明的显示。

[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"navImage"] forBarPosition:UIBarPositionAny barMetrics:UIBarMetricsDefault];
    
[self.navigationController.navigationBar setShadowImage:[UIImage new]];