Optimization and Debugging

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SwiftUI is well-known for its user-friendliness and high development efficiency, which are its main attractions. However, its inherent opacity presents significant challenges for developers in terms of optimization and effective debugging when issues arise.

Principles of SwiftUI

Optimization

Debugging

  • Intentional Design or Technical Flaw? The Anomaly of onChange in SwiftUI Multi-Layer Navigation

    SwiftUI provides the onChange modifier, allowing developers to listen for changes in specific values within a view and execute corresponding actions when those values change. Intuitively, as long as a view is part of the currently visible branch of the view tree (active), the corresponding closure should be triggered when the observed value changes. However, in certain navigation scenarios, the onChange modifier seems to become "selectively deaf," inexplicably remaining silent even when the observed value changes. Is this a carefully designed feature by Apple, or a long-hidden code defect? This article aims to unveil this phenomenon and provide necessary caution to developers.

  • Nested Grid Layout Anomaly: Analysis Approach and Resolution Strategies for SwiftUI Layout Issues

    After six iterations, SwiftUI is no longer a nascent framework. However, developers still occasionally encounter various peculiar issues stemming from bugs in the framework's code during its use. This article will dissect an instance of a Grid layout anomaly to explore analytical approaches and resolution strategies for addressing issues in day-to-day SwiftUI development.

  • Cracking the Code: The Mysterious @State Injection Mechanism

    This article will explore State injection optimization mechanism, the generation timing of modal views (Sheet, FullScreenCover), and data coordination between different contexts (mutually independent view trees) through a reproducible piece of "mysterious code".

  • Common Pitfalls Caused by Delayed State Updates in SwiftUI

    This article will explore two serious issues in SwiftUI caused by the failure to implement reactive programming principles, and provide corresponding solutions. Include after canceling the Sheet by gesture, quickly swiping right on the navigation container causes the application to lock up; and returning to the upper-level view while scrolling causes the application to crash.

  • The @State Specter: Analyzing a Bug in Multi-Window SwiftUI Applications

    In this article, we will delve into a bug affecting SwiftUI applications in multi-window mode and propose effective temporary solutions. We will not only detail the manifestation of this issue but also share the entire process from discovery to diagnosis, and finally, resolution. Through this exploration, our aim is to offer guidance to developers facing similar challenges, helping them better navigate the complexities of SwiftUI development.

  • SwiftUI geometryGroup() Guide: From Theory to Practice

    This article will introduce the concept and usage of geometryGroup(), as well as how to handle anomalies in older versions of SwiftUI without using geometryGroup().

  • How to Preview a SwiftUI View with Core Data Elements in Xcode

    This article will explore some of the reasons behind SwiftUI preview crashes, how to avoid similar crashes in future development, and how to safely and reliably preview SwiftUI views that contain Core Data elements in Xcode.