The navigation bar is a crucial component of the iOS user interface, providing a top-most area that displays navigation controls to the user. Since the release of iOS 11, there have been significant changes in how developers can customize the navigation bar, including modifications to its height, appearance, and behavior. Below, we delve into these customization options, with a focus on altering the navigation bar's height.

Understanding the Navigation Bar

The navigation bar in iOS is part of the `UINavigationController`, which manages the navigation stack of a view controller-based application. It provides users with contextual information about the current view and navigational elements to move within the app.

Key Components:

• Title: Displays the current view controller title.
• Bar Button Items: Include buttons such as `back`, `edit`, `done`, which are placed either on the left or right side.
• Prompt: An optional prompt message placed above the title text.

Customizing Navigation Bar Height in iOS 11

Traditionally, the height of the navigation bar is fixed and corresponds to the typical height of 44 points on most devices. Starting with iOS 11, however, `Apple` introduced some leeway in UIView customization, though not directly for the navigation bar height.

Technical Explanation

1. Custom Title View:
   • Introduce a custom title view by assigning a custom view to the `titleView` property of the navigation item. This effectively allows adding subviews that can dynamically adjust height, thereby indirectly causing the navigation bar to accommodate those changes.
   • iOS 11 introduced large titles to enhance the visual hierarchy, which can effectively change the perceived height of the navigation bar.
   • Further tweaking is possible by applying `Auto Layout` constraints or modifying the bar's content insets.
   • Directly changing the height of a `UINavigationBar` is not recommended as it may result in unsystematic UI appearance and unexpected behaviors during transition animations.
   • Introducing elements that alter the height need to maintain compliance with system constraints, ensuring adaptive layout functionality is unhampered.