iOS修改根视图控制器动画

方案一：

[UIView  transitionWithView:[[UIApplication sharedApplication].delegate window] duration:0.4 options:UIViewAnimationOptionTransitionCrossDissolve|UIViewAnimationOptionCurveEaseInOutanimations:^{

BOOLoldState = [UIViewareAnimationsEnabled];

[UIViewsetAnimationsEnabled:NO];

[[[UIApplicationsharedApplication].delegatewindow]setRootViewController:rootLoginNav];

[UIViewsetAnimationsEnabled:oldState];

}completion:NULL

];

方案二：

CATransition *animation = [CATransition animation];

[animation setDuration:0.6];//设置动画时间

animation.type = kCATransitionFade;//设置动画类型

[[UIApplication sharedApplication].keyWindow.layer addAnimation:animation forKey:nil];