在模态演示之前，如果layoutIfNeeded UINavigationController按钮消失

Question

Odd thing I am noticing:

let navController = UINavigationController(rootViewController: myRootViewController)
navController.view.layoutIfNeeded()
present(navController, animated: true, completion: nil)

In above code I am seeing the navigation controller bar button not showing when I add the layoutIfNeeded()

The reason I am trying to add this is I am finding the root view controller's view lays itself out while the modal presentation is happening. When I add the layoutIfNeeded it does the view layout before presenting which fixes my original problem.

Answer 1

尝试将navController.view.layoutIfNeeded（）扔到要显示的视图控制器的viewDidAppear：/ viewWillAppear：中，它应该对其进行修复。