Скачать или смотреть Fixing Screen Size Update on Orientation Change in SwiftUI

Learn how to effectively manage screen size updates during orientation changes in SwiftUI for iOS. Solve the common problem of delayed screen dimensions with a simple solution.
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Fixing Screen Size Update on Orientation Change in SwiftUI

When developing applications in SwiftUI for iOS, it's important to accurately capture the screen dimensions, especially when the device's orientation changes. A common stumbling block many developers face is that their app does not return the correct width and height immediately after a rotation. This can lead to unexpected layout scenarios and a poor user experience. In this guide, we will explore this issue and discuss a streamlined solution to ensure that screen size updates follow device orientation changes correctly.

The Problem

As you begin working with orientation changes, you might notice the following behavior when using UIScreen.main.bounds.size:

When the app launches in portrait mode, the dimensions might be height=736 and width=414.

Upon the first rotation to landscape, the values may remain the same (height=736 and width=414), as if the device isn’t registering the change.

Returning to portrait mode can sometimes yield reversed dimensions (height=414 and width=736), and further swaps only seem to propagate the confusing results.

This inconsistency can be frustrating and may leave you wondering, "What am I doing wrong?"

Understanding the Cause

The root of this issue primarily stems from how iOS handles device orientation and screen size updates. When you rotate your device, the system needs a moment to process that change. If you fetch the screen dimensions immediately, you might not get the updated size, leading to the confusion with orientation toggles.

The Solution

The solution to this issue is surprisingly simple: give the system a brief moment to properly register the orientation change before you fetch the new screen dimensions. A delay of one-tenth of a second (0.1 seconds) usually suffices to make this adjustment seamless for the user.

Here’s how you can implement this solution in your SwiftUI code:

Updated Code Snippet

Replace your current .onReceive method with the following:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Code

Notification Center: We're listening for UIDevice.orientationDidChangeNotification to know when the orientation has changed.

Task: Using Swift's concurrency features, we create a task that runs asynchronously on the main actor to ensure UI updates happen on the main thread.

Delay: The Task.sleep(for: .seconds(0.1)) introduces a short delay, allowing the device to "think" and update its boundaries.

Animation: The withAnimation block wraps the updating of the screen dimensions, triggering a smoother transition when the dimensions are changed.

Conclusion

Managing screen size updates during orientation changes in SwiftUI can initially be perplexing, but with a little patience and a simple delay, you can achieve the desired consistency in your app's layout. By implementing this straightforward solution, you'll ensure that your users have a seamless experience when rotating their device.

Happy coding! If you have any further questions or insights about SwiftUI and screen dimensions, feel free to share in the comments below!