- 实例化 alloc/init, initWithNibName
- awakeFromNib 从nib创建Controller对象
- get/set outlets
- viewDidLoad
- (几何内容确定时 才进入)viewWill/DidLayoutSubViews
- viewWill/DidAppear 进入屏幕时
- (可见内容有变化时 才有)viewWill/DidLayoutSubViews
- viewWill/DidDisappear 退出屏幕时
- (内存不足时)didReceivedMemoryWarning