导航栏 setBackgroundImage 在 iOS15 上不起作用答案

【问题标题】：navigationbar setBackgroundImage not working on iOS15导航栏 setBackgroundImage 在 iOS15 上不起作用
【发布时间】：2021-09-04 11:09:21
【问题描述】：

- (void)viewDidLoad {
   [super viewDidLoad];
   [self.navigationController.navigationBar setBackgroundImage:xxx] forBarMetrics:UIBarMetricsDefault];
   [self.navigationController.navigationBar setBarTintColor:[UIColor redColor]];
}

它在 iOS14 上完美运行。但在 iOS15、XCode13 beta 上，它不再工作了。

【问题讨论】：

标签： ios15

【解决方案1】：

我有同样的问题，这是我的代码：

if (@available(iOS 15.0, *)) {
        UINavigationBarAppearance *appearance = [[UINavigationBarAppearance alloc] init];
        [appearance configureWithOpaqueBackground];
        //appearance.backgroundColor = [UIColor blueColor];
        appearance.shadowColor = [UIColor whiteColor];
        appearance.titleTextAttributes = [NSDictionary dictionaryWithObjectsAndKeys:[UIColor colorWithRed:24.0/255.0 green:44.0/255.0 blue:122.0/255.0 alpha:1.0f], NSForegroundColorAttributeName,[UIFont fontWithName:@"AvenirNext-Demibold" size:21], NSFontAttributeName,nil];
        appearance.backgroundImage = [UIImage imageNamed:@"Bg_portrait_540x120_1.png"];
        self.navigationController.navigationBar.standardAppearance = appearance;
        self.navigationController.navigationBar.scrollEdgeAppearance = self.navigationController.navigationBar.standardAppearance;
    }

【讨论】：

【解决方案2】：

超频：

if (@available(iOS 15.0, *)) {
    UINavigationBarAppearance *appearance = [[UINavigationBarAppearance alloc] init];
    [appearance configureWithOpaqueBackground];
    appearance.backgroundColor = [UIColor whiteColor];
    appearance.shadowColor = [UIColor whiteColor];
    appearance.shadowImage = [UIImage imageWithColor:[UIColor whiteColor]];
    self.navigationController.navigationBar.standardAppearance = appearance;
    self.navigationController.navigationBar.scrollEdgeAppearance = self.navigationController.navigationBar.standardAppearance;
}

斯威夫特：

if #available(iOS 15.0, *) {
    let appearance = UINavigationBarAppearance()
    appearance.configureWithOpaqueBackground()
    appearance.backgroundColor = .white
    appearance.shadowColor = .white
    appearance.shadowImage = UIImage.color(.white)
    navigationController?.navigationBar.standardAppearance = appearance
    navigationController?.navigationBar.scrollEdgeAppearance = navigationController?.navigationBar.standardAppearance
}

【讨论】：

developer.apple.com/forums/thread/683265 谢谢问题解决
你的意思是如果#available(iOS 15.0, *) 对吗？ -> iOS 15.0

【解决方案3】：

迅速：

if #available(iOS 15.0, *) {
        let appearance = UINavigationBarAppearance()
        appearance.configureWithTransparentBackground()
        appearance.backgroundImage = image
        navigationController?.navigationBar.standardAppearance = appearance
        navigationController?.navigationBar.scrollEdgeAppearance = navigationController?.navigationBar.standardAppearance
    }else{
        self.navigationController?.navigationBar.setBackgroundImage(image, for: .default)
    }

【讨论】：

【解决方案4】：

只要使用这段代码，背景图片就可以在iOS 15中使用

if (@available(iOS 13.0, *)) {
  UINavigationBarAppearance *navigationBarAppearance = [UINavigationBarAppearance new];
  [navigationBarAppearance configureWithOpaqueBackground];
  [navigationBarAppearance setBackgroundImage:image];
  self.navigationController.navigationBar.scrollEdgeAppearance = navigationBarAppearance;
  self.navigationController.navigationBar.standardAppearance = navigationBarAppearance;
}

【讨论】：

至于 iOS 15.0 --- 在 navigationBarAppearance 对象上设置背景图片确实起到了作用。我花了不合理的时间来弄清楚这一点。因此，与其在 UINavigationBar 对象上使用 setBackgroundImage，不如在 UINavigationBarAppearance 对象上使用。前者对我的导航栏没有任何影响。