iphone - didFinishLaunchingWithOption 和 viewDidLoad 有什么区别

Question

didFinishLaunchingWithOption 和 viewDidLoad 这两个方法有什么区别？

前者是AppDlegate.m的一个方法后者是 ViewController.m 的一个方法，但它们都执行相同的任务，将 UI 加载到 View 上。

Answer 1

application:didFinishLaunchingWithOptions: 是一个 UIApplicationDelegate 协议(protocol)方法，当 iOS 完成为您的应用程序运行设置区域时调用该方法，并且是您的插入点，开发人员，加载 View Controller 等。

另一方面，viewDidLoad 方法是 UIViewController 类的一个方法，当 UIViewController 实例加载其 View 时调用该方法进入内存。来自苹果的文档:

Called after the controller’s view is loaded into memory.

Discussion This method is called after the view controller has loaded its view hierarchy into memory. This method is called regardless of whether the view hierarchy was loaded from a nib file or created programmatically in the loadView method. You usually override this method to perform additional initialization on views that were loaded from nib files.