在我的例子中，loadView()被中断 这段代码: 自我。edgesForExtendedLayout = UIRectEdgeNone

但删除loadView()后一切工作正常

Swift 4.2 - Xcode 10.0 - iOS 12.0:

if #available(iOS 11.0, *) {} else {
  self.edgesForExtendedLayout = []
  self.navigationController?.view.backgroundColor = .white
}

如果你想让视图有半透明的导航栏(这很好)，你必须设置一个contentInset或类似的。

我是这样做的:

// Check if we are running on ios7
if([[[[UIDevice currentDevice] systemVersion] componentsSeparatedByString:@"."][0] intValue] >= 7) {
      CGRect statusBarViewRect = [[UIApplication sharedApplication] statusBarFrame];
      float heightPadding = statusBarViewRect.size.height+self.navigationController.navigationBar.frame.size.height;

      myContentView.contentInset = UIEdgeInsetsMake(heightPadding, 0.0, 0.0, 0.0);
}

你可以通过在iOS7 SDK中实现一个名为edgesForExtendedLayout的新属性来实现这一点。请添加以下代码来实现此功能，

if ([self respondsToSelector:@selector(edgesForExtendedLayout)])
        self.edgesForExtendedLayout = UIRectEdgeNone;

你需要在你的-(void)viewDidLoad方法中添加上面的内容。

iOS 7 brings several changes to how you layout and customize the appearance of your UI. The changes in view-controller layout, tint color, and font affect all the UIKit objects in your app. In addition, enhancements to gesture recognizer APIs give you finer grained control over gesture interactions. Using View Controllers In iOS 7, view controllers use full-screen layout. At the same time, iOS 7 gives you more granular control over the way a view controller lays out its views. In particular, the concept of full-screen layout has been refined to let a view controller specify the layout of each edge of its view. The wantsFullScreenLayout view controller property is deprecated in iOS 7. If you currently specify wantsFullScreenLayout = NO, the view controller may display its content at an unexpected screen location when it runs in iOS 7. To adjust how a view controller lays out its views, UIViewController provides the following properties: edgesForExtendedLayout The edgesForExtendedLayout property uses the UIRectEdge type, which specifies each of a rectangle’s four edges, in addition to specifying none and all. Use edgesForExtendedLayout to specify which edges of a view should be extended, regardless of bar translucency. By default, the value of this property is UIRectEdgeAll. extendedLayoutIncludesOpaqueBars If your design uses opaque bars, refine edgesForExtendedLayout by also setting the extendedLayoutIncludesOpaqueBars property to NO. (The default value of extendedLayoutIncludesOpaqueBars is NO.) automaticallyAdjustsScrollViewInsets If you don’t want a scroll view’s content insets to be automatically adjusted, set automaticallyAdjustsScrollViewInsets to NO. (The default value of automaticallyAdjustsScrollViewInsets is YES.) topLayoutGuide, bottomLayoutGuide The topLayoutGuide and bottomLayoutGuide properties indicate the location of the top or bottom bar edges in a view controller’s view. If bars should overlap the top or bottom of a view, you can use Interface Builder to position the view relative to the bar by creating constraints to the bottom of topLayoutGuide or to the top of bottomLayoutGuide. (If no bars should overlap the view, the bottom of topLayoutGuide is the same as the top of the view and the top of bottomLayoutGuide is the same as the bottom of the view.) Both properties are lazily created when requested.

请参考，苹果医生

我有一个场景，我使用苹果编写的BannerViewController来显示我的广告和嵌入在BannerViewController中的ScrollViewController。

为了防止导航栏隐藏我的内容，我必须做两个更改。

1)修改BannerViewController.m

- (void)viewDidLoad
{
   [super viewDidLoad];
   float systemVersion = [[[UIDevice currentDevice] systemVersion] floatValue];
   if (systemVersion >= 7.0) {
      self.edgesForExtendedLayout = UIRectEdgeNone;
   }
}

2)修改我的scrollviewcontroller

- (void)viewDidLoad
{
    [super viewDidLoad];
    float systemVersion = [[[UIDevice currentDevice] systemVersion] floatValue];
    if (systemVersion >= 7.0) {
        self.edgesForExtendedLayout = UIRectEdgeBottom;
    }
}

现在广告正确地显示在视图的底部，而不是被导航栏覆盖，顶部的内容也没有被切断。

Swift 3 / Swift 4解决方案，也适用于iOS 10+中的nib /XIB文件:

override func viewDidLoad() {
    super.viewDidLoad()

    edgesForExtendedLayout = []
}