关于self.window.rootViewController的方法调用顺序

关于self.window.rootViewController设置window根控制器，的方法调用顺序

/*
         *root控制器添加到window.rootViewController控制器时，root控制器的viewDidLoad才会被调用
         *
         */
        RootViewController *root = [RootViewController sharedInstance];
        root.registType = 1;
        self.window.rootViewController = root;

在RootViewController中，setRegistType:方法会先被调用，给self.registType赋值后，再调用viewDidLoad

- (void)viewDidLoad {
    [super viewDidLoad];
    _firstShowView = [[MideaFirstLoginShowView alloc] initWithFrame:CGRectMake(0, 64, SCREEN_WIDTH, 64)];
    _firstShowView.registType = self.registType;
    [_homeVC.view addSubview:_firstShowView];
}

- (void)setRegistType:(NSInteger)registType {
    if (_registType != registType) {
        _registType = registType;
    }
}