当你重写的方法是加载或者初始化的方法时, 你要先调用 super, 比如init…, viewWillAppear, viewDidLoad, setUp 方法; 当你冲写的方法是卸载的方法时, 你要后调用 super, 比如 dealloc, viewDidUnload, viewWillDisappear, tearDown 方法.
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
//code...
}
- (void)viewWillDisappear:(BOOL)animated
{
//code...
[super viewWillDisappear:animated];
}