iOS：控制器的生命周期

关于UIViewController生命周期的几个函数：

- (id)init {
    NSLog(@"%s", __func__);
    if(self = [super init]) {
    }
    return self;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.view.backgroundColor = [UIColor lightGrayColor];
    NSLog(@"%s", __func__);
    [self hf_addButton];
}
- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    NSLog(@"%s", __func__);
}
- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    NSLog(@"%s", __func__);
}
- (void)viewWillLayoutSubviews {
    [super viewWillLayoutSubviews];
    NSLog(@"%s", __func__);
}
- (void)viewDidLayoutSubviews {
    [super viewDidLayoutSubviews];
    NSLog(@"%s", __func__);
}
- (void)viewDidDisappear:(BOOL)animated {
    [super viewDidDisappear:animated];
    NSLog(@"%s", __func__);
}
- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    NSLog(@"%s", __func__);

}
- (void)dealloc {
    NSLog(@"%s", __func__);
}

ViewController - - push 到 - HFLifeStyleViewController

输出如下：

输出：
-[HFLifeStyleViewController init]
-[HFLifeStyleViewController loadView]
-[HFLifeStyleViewController viewDidLoad]
-[ViewController viewWillDisappear:]
-[HFLifeStyleViewController viewWillAppear:]
-[HFLifeStyleViewController viewWillLayoutSubviews]
-[HFLifeStyleViewController viewDidLayoutSubviews]
-[HFLifeStyleViewController viewDidAppear:]
-[ViewController viewDidDisappear:]

注意：若ViewController present 到 HFLifeStyleViewController时

iOS13默认modalPresentationStyle是UIModalPresentationAutomatic。

若HFLifeStyleViewController的modalPresentationStyle不是UIModalPresentationFullScreen样式

HFLifeStyleViewController显示出来时，ViewController没有执行dissppear相关方法。

输出如下：

-[HFLifeStyleViewController init]
-[HFLifeStyleViewController viewDidLoad]
-[HFLifeStyleViewController viewWillAppear:]
-[HFLifeStyleViewController viewWillLayoutSubviews]
-[HFLifeStyleViewController viewDidLayoutSubviews]
-[HFLifeStyleViewController viewWillLayoutSubviews]
-[HFLifeStyleViewController viewDidLayoutSubviews]
-[HFLifeStyleViewController viewDidAppear:]

注意：

viewWillLayoutSubviews、viewDidLayoutSubviews可能会调用多次

当控件布局将要变化、已经变化时 会多次调用。

HFLifeStyleViewController完整的生命周期：

-[ViewController viewWillAppear:]
-[ViewController viewWillLayoutSubviews]
-[ViewController viewDidLayoutSubviews]
-[ViewController viewDidAppear:]
-[HFLifeStyleViewController init]
-[HFLifeStyleViewController viewDidLoad]
-[ViewController viewWillDisappear:]
-[HFLifeStyleViewController viewWillAppear:]
-[HFLifeStyleViewController viewWillLayoutSubviews]
-[HFLifeStyleViewController viewDidLayoutSubviews]
-[HFLifeStyleViewController viewDidAppear:]
-[ViewController viewDidDisappear:]
-[HFLifeStyleViewController viewWillDisappear:]
-[ViewController viewWillAppear:]
-[ViewController viewDidAppear:]
-[HFLifeStyleViewController viewDidDisappear:]
-[HFLifeStyleViewController dealloc]