iOS - ViewController生命周期

initWithCoder:(NSCoder *)aDecoder： 加载xib，storyboard，纯代码用不到
loadView:加载view
viewDidLoad：view加载完毕
viewWillAppear：控制器的view将要显示
viewWillLayoutSubviews：控制器的view将要布局子控件
viewDidLayoutSubviews：控制器的view布局子控件完成
这期间系统可能会多次调用viewWillLayoutSubviews、 viewDidLayoutSubviews 俩个方法
viewDidAppear:控制器的view完全显示
viewWillDisappear：控制器的view即将消失的时候
这期间系统也会调用viewWillLayoutSubviews 、viewDidLayoutSubviews两个方法
viewDidDisappear：控制器的view完全消失的时候
didReceiveMemoryWarning 当app收到内存警告的时候会发消息给视图控制器。
viewWillUnload：（iOS6废除）
viewDidUnload：（iOS6废除）

总结：
整个控制器声明周期：
viewDidLoad -> viewWillAppear -> viewWillLayoutSubviews -> viewDidLayoutSubviews -> viewDidAppear -> viewWillDisappear -> viewDidDisappear

image.png

Demo

控制器1：（跳转到控制器2代码类似）

@interface ViewController ()
@property (nonatomic, assign)NSInteger count;
@end

@implementation ViewController
- (instancetype)init {
    
    self = [super init];
    if (self) {
        self.count = 0;
    }
    return self;
}

- (void)loadView {
    [super loadView];
    NSLog(@"ViewController%s------%ld", __func__, (long)self.count);
    self.count++;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    NSLog(@"ViewController%s------%ld", __func__, (long)self.count);
    self.count ++;
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    self.count++;
    NSLog(@"ViewController%s------%ld", __func__, (long)self.count);
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    self.count++;
    NSLog(@"ViewController%s------%ld", __func__, (long)self.count);
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    self.count++;
    NSLog(@"ViewController%s------%ld", __func__, (long)self.count);
}

- (void)viewDidDisappear:(BOOL)animated {
    [super viewDidDisappear:animated];
    self.count++;
    NSLog(@"ViewController%s------%ld", __func__, (long)self.count);
}

- (void)viewWillLayoutSubviews {
    [super viewWillLayoutSubviews];
    self.count++;
    NSLog(@"ViewController%s------%ld", __func__, (long)self.count);
}

- (void)viewDidLayoutSubviews {
    [super viewDidLayoutSubviews];
    self.count++;
    NSLog(@"ViewController%s------%ld", __func__, (long)self.count);
}


- (IBAction)buttonClick:(id)sender {
    
    Test1ViewController *test = [[Test1ViewController alloc] init];
    [self.navigationController pushViewController:test animated:YES];
}

打印结果：

image.png

image.png

• push的时候生命周期：

  
  
  

  image.png

• pop的时候生命周期：

  
  
  

  image.png

参考文章：
https://www.jianshu.com/p/42eb5a930d66
http://www.cocoachina.com/cms/wap.php?action=article&id=23326
iOS系统中导航栏的转场解决方案与最佳实践