WeChat Client Technology Team

Nov 19, 2015 · Mobile Development

Unlocking iOS Event Handling & Rendering: RunLoop, UI Threads, and Core Animation

This article explains iOS’s event processing pipeline—from hardware events through the RunLoop’s observer, source, timer, and dispatch mechanisms—detailing why UI must run on the main thread, how CALayer and Core Animation render, and the roles of CADisplayLink, NSTimer, and async display techniques.