将navigationBar背景图像设置为[UIImage new]后恢复

Question

我需要一个完全透明的mapView导航栏,所以我这样做:

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

这会返回所需的效果,如下所示:

现在,当我去其他任何地方时我遇到了问题,因为我的navigationBar仍然是透明的:

如何恢复navigationBar的backgroundImage和shadowImage的默认设置？

Answer 1

在地图视图上为导航控制器的图像设置nilviewWillDisappear

在mapview中设置这两个方法

MapView .m

-(void)viewWillAppear:(BOOL)animated{
    [self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
    [self.navigationController.navigationBar setShadowImage:[UIImage new]];
}

-(void)viewWillDisappear:(BOOL)animated{
    [self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
    [self.navigationController.navigationBar setShadowImage:nil];
}

Answer 2

对于Swift 3:

override func viewWillAppear(_ animated: Bool) {
  super.viewWillAppear(animated)

  self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: UIBarMetrics.default)
  self.navigationController?.navigationBar.shadowImage = UIImage()
}

override func viewWillDisappear(_ animated: Bool) {
  super.viewWillDisappear(animated)

  self.navigationController?.navigationBar.setBackgroundImage(nil, for: UIBarMetrics.default)
  self.navigationController?.navigationBar.shadowImage = nil
}