話說作了iOS幾年,對於UIViewController和UIView的生命週期函數一直不是很重視,致使了不少模糊的地方。今天專門寫一個Demo來驗證一下,發現不一樣加載方式差異仍是蠻大的。git
每一種加載方式所調用的加載方法不一樣,並且還有一些細節地方不一樣。蘋果爲咱們提供了四種默認的加載方式,不過我是純代碼黨,AutoLayout之後,咱們經過Masonry這個第三方佈局利器來佈局,在我Git上也有專門總結的不一樣佈局解決方案。接下來咱們看看系統的四種方式,猶豫沒有什麼理論性的東西,我就直接上代碼爲主了:github
經過XIB加載。app
經過StoryBoard加載。函數
經過NSCoding協議加載。佈局
經過代碼加載。code
首先看初始化代碼:生命週期
- (IBAction)loadControllerFromXIB:(id)sender { XIBViewController *xibVC = [[XIBViewController alloc]initWithNibName:@"XIBViewController" bundle:[NSBundle mainBundle]]; [self.navigationController pushViewController:xibVC animated:YES]; }
當咱們不實現loadView
的時候打印結果:get
2017-04-15 12:05:32.974 UIViewController和UIView生命週期加載和卸載[59883:1192231] initWithNibName 2017-04-15 12:05:32.987 UIViewController和UIView生命週期加載和卸載[59883:1192231] viewDidLoad 2017-04-15 12:05:32.987 UIViewController和UIView生命週期加載和卸載[59883:1192231] viewWillAppear 2017-04-15 12:05:32.996 UIViewController和UIView生命週期加載和卸載[59883:1192231] viewWillLayoutSubviews 2017-04-15 12:05:32.997 UIViewController和UIView生命週期加載和卸載[59883:1192231] viewDidLayoutSubviews 2017-04-15 12:05:33.002 UIViewController和UIView生命週期加載和卸載[59883:1192231] viewWillLayoutSubviews 2017-04-15 12:05:33.002 UIViewController和UIView生命週期加載和卸載[59883:1192231] viewDidLayoutSubviews 2017-04-15 12:05:33.506 UIViewController和UIView生命週期加載和卸載[59883:1192231] viewDidAppear 2017-04-15 12:05:37.142 UIViewController和UIView生命週期加載和卸載[59883:1192231] clickButton //pop之後 2017-04-15 12:05:42.334 UIViewController和UIView生命週期加載和卸載[59883:1192231] viewWillDisappear 2017-04-15 12:05:42.837 UIViewController和UIView生命週期加載和卸載[59883:1192231] viewDidDisappear 2017-04-15 12:05:42.838 UIViewController和UIView生命週期加載和卸載[59883:1192231] dealloc
我發現一個很奇怪的現象。若是用XIB加載的控制器,而且實現了一個空loadView
,那麼咱們在XIB設置的視圖都失效了,應該是系統返回了一個默認的視圖覆蓋了。可是用Storyboard加載的視圖,實現一個空的loadView
則不會丟失Storyboard裏面的視圖,這個是用XIB和Storyboard的一個注意點
。源碼
-(void)loadView{ [super loadView]; NSLog(@"loadView"); }
初始化代碼:博客
- (IBAction)laodControllerFromSB:(id)sender { UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Second" bundle:[NSBundle mainBundle]]; SBViewController *sbVC = [sb instantiateViewControllerWithIdentifier:@"SBViewController"]; [self.navigationController pushViewController:sbVC animated:YES]; }
運行結果:
2017-04-15 12:26:45.364 UIViewController和UIView生命週期加載和卸載[59932:1194239] initWithCoder 2017-04-15 12:26:45.365 UIViewController和UIView生命週期加載和卸載[59932:1194239] awakeFromNib 2017-04-15 12:26:45.368 UIViewController和UIView生命週期加載和卸載[59932:1194239] loadView 2017-04-15 12:26:45.368 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidLoad 2017-04-15 12:26:45.368 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillAppear 2017-04-15 12:26:45.372 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillLayoutSubviews 2017-04-15 12:26:45.373 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidLayoutSubviews 2017-04-15 12:26:45.877 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidAppear //pop之後 2017-04-15 12:26:50.669 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillDisappear 2017-04-15 12:26:51.172 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidDisappear 2017-04-15 12:26:51.172 UIViewController和UIView生命週期加載和卸載[59932:1194239] dealloc
對於Storyboard,使用一個空的loadView
沒有影響。
初始化代碼:
//這裏我就不實現NSCoding協議了,直接傳入一個nil參數。 - (IBAction)loadControllerFromCoder:(id)sender { CoderViewController *coderVC = [[CoderViewController alloc]initWithCoder:nil]; [self.navigationController pushViewController:coderVC animated:YES]; }
運行結果:
2017-04-15 12:30:25.962 UIViewController和UIView生命週期加載和卸載[59932:1194239] initWithCoder 2017-04-15 12:30:25.963 UIViewController和UIView生命週期加載和卸載[59932:1194239] loadView 2017-04-15 12:30:25.963 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidLoad 2017-04-15 12:30:25.963 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillAppear 2017-04-15 12:30:25.967 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillLayoutSubviews 2017-04-15 12:30:25.967 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidLayoutSubviews 2017-04-15 12:30:25.968 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillLayoutSubviews 2017-04-15 12:30:25.968 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidLayoutSubviews 2017-04-15 12:30:26.470 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidAppear //pop之後 2017-04-15 12:30:28.034 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillDisappear 2017-04-15 12:30:28.537 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidDisappear 2017-04-15 12:30:28.537 UIViewController和UIView生命週期加載和卸載[59932:1194239] dealloc
初始化代碼:
- (IBAction)loadControllerWithNone:(id)sender { CodeViewController *codeVC = [[CodeViewController alloc]init]; [self.navigationController pushViewController:codeVC animated:YES]; }
運行結果:
2017-04-15 12:31:48.785 UIViewController和UIView生命週期加載和卸載[59932:1194239] initWithNibName 2017-04-15 12:31:48.786 UIViewController和UIView生命週期加載和卸載[59932:1194239] init 2017-04-15 12:31:48.787 UIViewController和UIView生命週期加載和卸載[59932:1194239] loadView 2017-04-15 12:31:48.787 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidLoad 2017-04-15 12:31:48.788 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillAppear 2017-04-15 12:31:48.792 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillLayoutSubviews 2017-04-15 12:31:48.792 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidLayoutSubviews 2017-04-15 12:31:48.792 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillLayoutSubviews 2017-04-15 12:31:48.792 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidLayoutSubviews 2017-04-15 12:31:49.293 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidAppear //pop之後 2017-04-15 12:31:55.594 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewWillDisappear 2017-04-15 12:31:56.098 UIViewController和UIView生命週期加載和卸載[59932:1194239] viewDidDisappear 2017-04-15 12:31:56.098 UIViewController和UIView生命週期加載和卸載[59932:1194239] dealloc
初始化代碼:
- (IBAction)loadViewFromXib:(id)sender { XibView *xibView = [[[NSBundle mainBundle]loadNibNamed:@"XIBView" owner:self options:nil] lastObject]; [self.view addSubview:xibView]; }
運行結果:
2017-04-15 12:33:22.194 UIViewController和UIView生命週期加載和卸載[59932:1194239] initWithCoder 2017-04-15 12:33:22.195 UIViewController和UIView生命週期加載和卸載[59932:1194239] awakeFromNib 2017-04-15 12:33:22.195 UIViewController和UIView生命週期加載和卸載[59932:1194239] willMoveToWindow 2017-04-15 12:33:22.195 UIViewController和UIView生命週期加載和卸載[59932:1194239] willMoveToSuperview 2017-04-15 12:33:22.196 UIViewController和UIView生命週期加載和卸載[59932:1194239] didMoveToWindow 2017-04-15 12:33:22.196 UIViewController和UIView生命週期加載和卸載[59932:1194239] didMoveToSuperview 2017-04-15 12:33:22.197 UIViewController和UIView生命週期加載和卸載[59932:1194239] layoutSubviews //這裏是點擊移除之後 2017-04-15 12:33:25.769 UIViewController和UIView生命週期加載和卸載[59932:1194239] willMoveToSuperview 2017-04-15 12:33:25.770 UIViewController和UIView生命週期加載和卸載[59932:1194239] willMoveToWindow 2017-04-15 12:33:25.771 UIViewController和UIView生命週期加載和卸載[59932:1194239] didMoveToWindow 2017-04-15 12:33:25.771 UIViewController和UIView生命週期加載和卸載[59932:1194239] didMoveToSuperview 2017-04-15 12:33:25.771 UIViewController和UIView生命週期加載和卸載[59932:1194239] dealloc
初始化代碼:
- (IBAction)loadViewWithNone:(id)sender { CodeView *codeView = [[CodeView alloc]init]; codeView.backgroundColor = [UIColor greenColor]; codeView.frame = CGRectMake(0, 500, 100, 50); [self.view addSubview:codeView]; }
運行結果:
2017-04-15 12:38:57.562 UIViewController和UIView生命週期加載和卸載[60323:1208772] initWithFrame 2017-04-15 12:38:57.562 UIViewController和UIView生命週期加載和卸載[60323:1208772] init 2017-04-15 12:38:57.562 UIViewController和UIView生命週期加載和卸載[60323:1208772] willMoveToWindow 2017-04-15 12:38:57.563 UIViewController和UIView生命週期加載和卸載[60323:1208772] willMoveToSuperview 2017-04-15 12:38:57.563 UIViewController和UIView生命週期加載和卸載[60323:1208772] didMoveToWindow 2017-04-15 12:38:57.563 UIViewController和UIView生命週期加載和卸載[60323:1208772] didMoveToSuperview 2017-04-15 12:38:57.564 UIViewController和UIView生命週期加載和卸載[60323:1208772] layoutSubviews //點擊移除之後 2017-04-15 12:39:02.751 UIViewController和UIView生命週期加載和卸載[60323:1208772] willMoveToSuperview 2017-04-15 12:39:02.752 UIViewController和UIView生命週期加載和卸載[60323:1208772] willMoveToWindow 2017-04-15 12:39:02.752 UIViewController和UIView生命週期加載和卸載[60323:1208772] didMoveToWindow 2017-04-15 12:39:02.752 UIViewController和UIView生命週期加載和卸載[60323:1208772] didMoveToSuperview 2017-04-15 12:39:02.752 UIViewController和UIView生命週期加載和卸載[60323:1208772] 點擊移除 2017-04-15 12:39:02.753 UIViewController和UIView生命週期加載和卸載[60323:1208772] dealloc
UIViewController不一樣加載方式鉤子函數總結:
XIB加載方式
initWithNibName
loadView(注意:若是實現一個空的方法,則XIB設置的屬性無效,會覆蓋XIB中的設置
)
viewDidLoad
Storyboard加載方式
initWithCoder
awakeFromNib
loadView(實現是一個空方法或者不實現沒有影響
)
viewDidLoad
NSCoding加載方式
initWithCoder
loadView
viewDidLoad
代碼加載方式
initWithNibName
init(這個是我初始化的時候主動調用,若是用initWithNibName傳入nil參數則不會調用
)
loadView
viewDidLoad
咱們能夠發現,代碼加載方式和XIB加載方式如出一轍,若是有XIB則加載XIB,若是沒有XIB則能夠代碼添加視圖。
UIView不一樣加載方式鉤子函數總結:
XIB加載方式
initWithCoder
awakeFromNib
willMoveToWindow
代碼加載方式
initWithFrame(設置frame。
)
init(init方法調用
)
willMoveToWindow
咱們發現,若是經過init初始化,而後手動設置Frame。則會致使上面的調用順序。
源碼連接UIViewController和UIView生命週期加載和卸載。博客地址博客地址。