备忘

 标题栏消失动画（navigation）

self.mainNavigationController setNavigationBarHidden:<#(BOOL)#> animated:<#(BOOL)#>

更改标题栏颜色

self.navigationController.navigationBar.tintColor = [UIColor whiteColor];

更改电池颜色  （vc）

-(UIStatusBarStyle)preferredStatusBarStyle

{

return UIStatusBarStyleLightContent;

}

//

只需要一个静态变量就可以了

static BOOL first = YES;

if (first) {

//加载

first = NO;

}

找下层vc

id object = [self nextResponder];

while (![object isKindOfClass:[HomeViewController class]] &&

object != nil) {

object = [object nextResponder];

}

HomeViewController *homeVC = (HomeViewController *)object;