控制器的生命周期方法题及内存警告时的处理

1.图解

2.方法解释

- (void)loadView
{
//一定调用父类的方法
[super loadView];

//在这里实例化self.view
//一般不重写这个方法

SHOW_FUNC;
}

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
SHOW_FUNC;
}

//即将显示到屏幕上
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];

SHOW_FUNC;
}

//已经显示到屏幕上
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
SHOW_FUNC;
}

//即将离开屏幕，切换到其他视图控制器
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];

SHOW_FUNC;
}

//已经离开当前视图控制器
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
SHOW_FUNC;
}

//内存紧张
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.

SHOW_FUNC;
}

//view已经销毁
- (void)viewDidUnload
{
[super viewDidUnload];
}

//view即将销毁
- (void)viewWillUnload
{
[super viewWillUnload];
}

内存警告处理