呈現控制器並使其成爲根控制器

Question

我有一種方法，呈現控制器並使呈現控制器成爲根控制器。它在Xcode 5中工作正常，但在Xcode 6中它崩潰。我需要出示視圖控制器，使之根，沒有任何查看錯誤......舊的代碼崩潰，新的有錯誤，同時也使根控制器

原代碼

-(void)presentViewController:(UIViewController *)controller withCompletion:(void(^)(void))completion 
{ 
    UIViewController *currentController; 
    currentController = [self controller]; 
    [currentController presentViewController:controller animated:true completion:^{ 
     [controller dismissViewControllerAnimated:false completion:NULL]; 
     if(completion){ 
      completion(); 
     } 
    }]; 
} 

試圖與延遲來改變它像

-(void)presentViewController:(UIViewController *)controller withCompletion:(void(^)(void))completion 
{ 
    UIViewController *currentController; 
    currentController = [self controller]; 
    [currentController presentViewController:controller animated:true completion:^{ 
     //use delay before execution 
     dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ 
      [controller dismissViewControllerAnimated:false completion:NULL]; 
      if(completion){ 
       completion(); 
      } 

     }); 
    }]; 
} 

但是，我有視圖閃爍與以前的看法。也試圖使不在一個區塊

-(void)presentViewController:(UIViewController *)controller withCompletion:(void(^)(void))completion 
{ 
    UIViewController *currentController; 
    currentController = [self controller]; 
    [currentController presentViewController:controller animated:true completion:NULL]; 
    [controller dismissViewControllerAnimated:false completion:NULL]; 
    if(completion){ 
     completion(); 
    } 
} 

但這種方式我堅持以前的看法。

Answer 1

首先，你需要從Window對象獲得主導航控制器：

UIWindow *keyWindow = [[[UIApplication sharedApplication] delegate] window]; 
UINavigationController *rootNavController = (UINavigationController *)keyWindow.rootViewController; 

，並設置新的根視圖 - 控制

UIViewController *rootViewController = [[UIViewController alloc] init]; 
[rootNavController setViewControllers:@[rootViewController] animated:NO]; 
[rootNavController pushViewController:rootViewController animated:YES completion:^{ 
    NSLog(@"rootViewController shown"); 
}];