Скачать или смотреть Solving the SwiftUI Animation Dilemma: Transitioning from animation(_:) to animation(_:value:)

Discover why your `SwiftUI` animations aren't working with the new `animation(_:value:)` modifier. Learn how to effectively use this powerful tool in your applications!
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This video is based on the question https://stackoverflow.com/q/70446342/ asked by the user 'Dan' ( https://stackoverflow.com/u/4037158/ ) and on the answer https://stackoverflow.com/a/70451142/ provided by the user 'Yrb' ( https://stackoverflow.com/u/7129318/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Introduction

Have you ever faced the frustrating issue of animations not working in SwiftUI when transitioning from the old animation(_:) modifier to the new animation(_:value:)? This problem can be perplexing, especially if you're used to the convenience of the deprecated version. In this guide, we'll explore this common issue and provide a clear, pragmatic solution to ensure your SwiftUI animations run smoothly.

Understanding the Problem

When you attempted to use the animation(_:value:) modifier as shown in the following code snippet, you may have noticed that your animation fails to trigger:

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

In contrast, you observed that a setup without state changes could successfully animate:

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

Why does this happen? The core difference lies in how these animation modifiers function.

Breaking Down the Solution

Implicit vs. Explicit Animation

The Previous animation(_:) Modifier

Implicit Animation: The older animation(_:) modifier allowed any UI change to trigger animations. This could lead to unexpected behavior since the system had to guess which values you wanted to animate.

Deprecated: Due to the unpredictable nature and side effects, Apple has deprecated this modifier in favor of a more controlled animation approach.

The New animation(_:value:) Modifier

Explicit Animation: The updated animation(_:value:) requires explicit instructions. This means it will only trigger when the specified value changes.

On Appear Trigger: Simply placing it on a view will not animate it unless the value changes through certain actions, like a state change within an onAppear() function.

Implementing Effective Animations

To get your animations working seamlessly with animation(_:value:), consider the following code structure that effectively demonstrates this strategy:

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

Key Adjustments in This Code

Separate Animation State: Using a dedicated @ State private var animate variable allows you to separately manage what you want to animate and prevent unnecessary side effects.

Opacity Changes: The opacity of the button toggles based on the animate state, creating a smoother visual transition.

Using onAppear(): The animation will trigger when the view appears, ensuring that the button fades in appropriately.

Conclusion

Understanding the transition from the deprecated animation(_:) to the more precise animation(_:value:) can greatly improve your SwiftUI applications. By leveraging explicit state changes and properly managing your animation triggers, you'll be able to create engaging and dynamic user interfaces with ease.

Start applying these principles in your SwiftUI projects today, and watch your animations come to life!