在要实现透明导航栏的控制器中
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
//去除 navigationBar 底部的细线
self.navigationController.navigationBar.shadowImage = [UIImage new];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
[self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
self.navigationController.navigationBar.shadowImage = nil;
}
