这里有一个简单的答案，可以找到所有iphone的安全区域高度

let window = UIApplication.shared.windows[0]

let SafeAreaHeight = window.safeAreaLayoutGuide.layoutFrame.size.height

这里的其他答案对我都没用，但这个对我有用。

var topSafeAreaHeight: CGFloat = 0
var bottomSafeAreaHeight: CGFloat = 0

  if #available(iOS 11.0, *) {
    let window = UIApplication.shared.windows[0]
    let safeFrame = window.safeAreaLayoutGuide.layoutFrame
    topSafeAreaHeight = safeFrame.minY
    bottomSafeAreaHeight = window.frame.maxY - safeFrame.maxY
  }

我正在使用CocoaPods框架和UIApplication。shared不可用，然后我在视图窗口中使用safeAreaInsets:

if #available(iOS 11.0, *) {
    let insets = view.window?.safeAreaInsets
    let top = insets.top
    let bottom = insets.bottom
}

extension UIViewController {
    var topbarHeight: CGFloat {
        return
            (view.window?.safeAreaInsets.top ?? 0) +
            (view.window?.windowScene?.statusBarManager?.statusBarFrame.height ?? 0.0) +
            (self.navigationController?.navigationBar.frame.height ?? 0.0)
    }
}

UIWindow *window = [[[UIApplication sharedApplication] delegate] window]; 
CGFloat fBottomPadding = window.safeAreaInsets.bottom;

要获得布局参考线之间的高度，只需这样做

let guide = view.safeAreaLayoutGuide
let height = guide.layoutFrame.size.height

所以全帧高度= 812.0，安全区高度= 734.0

下面的例子中，绿色视图的框架为guide.layoutFrame