How iOS screenshot detection works beyond the basic UIKit notification

iOS provides a UIKit notification called UIApplication.userDidTakeScreenshotNotification that signals when a screenshot is taken, but it does not deliver the actual image or a ready-to-use view controller. Developers must handle the gap by capturing the active key window as a fallback image and, if Photos access is granted, retrieving the actual screenshot asset afterward. The notification handler is kept lightweight, hopping to the main queue and checking conditions such as app state, scene activity, and whether a reporter is already on screen before presenting anything. A scene-aware window lookup is necessary to avoid breakage in apps using multiple scenes, and the top-most view controller is resolved by recursively traversing navigation and tab bar hierarchies. These extra steps transform a single, minimal signal into a reliable bug-reporting flow that accounts for timing gaps, missing permissions, and duplicate presentations.