iOS 控制器多次present push后返回根控制器

1

UIViewController *vc = self.presentingViewController;

if (!vc.presentingViewController)   return;  
  
while (vc.presentingViewController)  {  
    vc = vc.presentingViewController;  
}  
  
[vc dismissViewControllerAnimated:YES completion:nil];  

2

TargetVC *target = [[TargeVC alloc] init];  
  
UIViewController *vc = self.presentingViewController;  
  
if (!vc.presentingViewController) return;  
  
while (![vc isKindOfClass:[target class]])  {  
    vc = vc.presentingViewController;  
}  
  
[vc dismissViewControllerAnimated:YES completion:nil];  

3

if ([self respondsToSelector:@selector(presentingViewController)]) {

[self.presentingViewController.presentingViewController 

dismissViewControllerAnimated:YES completion:nil];

}