AppDelegate 的当前视图控制器？

Question

有没有办法从 AppDelegate 获取当前视图控制器？ 我知道有 rootViewController，但这不是我要找的。

Answer 1

如果您的应用程序的根视图控制器是UINavigationController您可以这样做：

((UINavigationController*)appDelegate.window.rootViewController).visibleViewController;

同样，如果它是一个UITabBarController你可以这样做：

((UITabBarController*)appDelegate.window.rootViewController).selectedViewController;

当然，像这样的显式铸造很脏。 更好的方法是使用强类型捕获引用。

Answer 2

这可能有所帮助

- (UIViewController *)topViewController{
  return [self topViewController:[UIApplication sharedApplication].keyWindow.rootViewController];
}

- (UIViewController *)topViewController:(UIViewController *)rootViewController
{
  if (rootViewController.presentedViewController == nil) {
    return rootViewController;
  }

  if ([rootViewController.presentedViewController isKindOfClass:[UINavigationController class]]) {
    UINavigationController *navigationController = (UINavigationController *)rootViewController.presentedViewController;
    UIViewController *lastViewController = [[navigationController viewControllers] lastObject];
    return [self topViewController:lastViewController];
  }

  UIViewController *presentedViewController = (UIViewController *)rootViewController.presentedViewController;
  return [self topViewController:presentedViewController];
}

Swift版本：

extension UIApplication {
    class func topViewController(base: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
        if let nav = base as? UINavigationController {
            return topViewController(base: nav.visibleViewController)
        }
        if let tab = base as? UITabBarController {
            if let selected = tab.selectedViewController {
                return topViewController(base: selected)
            }
        }
        if let presented = base?.presentedViewController {
            return topViewController(base: presented)
        }
        return base
    }
}

取自： https ： //gist.github.com/snikch/3661188

Answer 3

如果你有UINavigationController到appDelegate然后使用它的属性topViewController或visibleViewController

Answer 4

进行扩展：

extension UIApplication {
    class func topViewController(base: UIViewController? = UIApplication.sharedApplication().keyWindow?.rootViewController) -> UIViewController? {
        if let nav = base as? UINavigationController {
            return topViewController(nav.visibleViewController)
        }
        if let tab = base as? UITabBarController {
            let moreNavigationController = tab.moreNavigationController

            if let top = moreNavigationController.topViewController where top.view.window != nil {
                return topViewController(top)
            } else if let selected = tab.selectedViewController {
                return topViewController(selected)
            }
        }
        if let presented = base?.presentedViewController {
            return topViewController(presented)
        }
        return base
    }
}

用法：

if let rootViewController = UIApplication.topViewController() {
    //do sth with root view controller
}

Answer 5

获取appDelegate对象：

MyAppDelegate *tmpDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];

由于beryllium建议您可以使用UINavigationController的属性来访问当前的视图控制器。

所以代码看起来像：

id myCurrentController = tmpDelegate.myNavigationController.topViewController;

要么：

NSArray *myCurrentViewControllers = tmpDelegate.myNavigationController.viewControllers;

Answer 6

您可以通过查找其presentViewController从rootViewController获取当前视图控制器，如下所示：

UIViewController *parentViewController = [[[UIApplication sharedApplication] delegate] window].rootViewController;

while (parentViewController.presentedViewController != nil){
    parentViewController = parentViewController.presentedViewController;
}
UIViewController *currentViewController = parentViewController;

它适用于我。 希望能帮助到你 ：）

Answer 7

对于没有使用UINavigationController ，而是他们的默认视图控制器是UIViewController您可以使用AppDelegate的以下内容检查哪个视图控制器处于活动状态（或呈现）：

func application(application: UIApplication, supportedInterfaceOrientationsForWindow window: UIWindow?) -> Int {
    if let rootViewController = self.window!.rootViewController {
        if let presentedViewController = rootViewController.presentedViewController {
            return presentedViewController.supportedInterfaceOrientations()
        }
    } // Else current view controller is DefaultViewController

    return Int(UIInterfaceOrientationMask.Portrait.rawValue)
}

如您所见，我正在检查当前的视图控制器，以支持特定视图控制器的不同接口方向。 对于任何对使用此方法支持特定内容感兴趣的人，应将其放置在需要特定方向的每个视图控制器中。

override func supportedInterfaceOrientations() -> Int {
    return Int(UIInterfaceOrientationMask.All.rawValue)
} 

注意：此代码是使用Swift 1.2编写的

Answer 8

Swift解决方案：

 self.window.rootViewController.presentedViewController. 

这应该可以满足你的需求。

Answer 9

基于AG解决方案的 Swift 4+语法中的UIApplication扩展

public extension UIApplication {

    class func topViewController(base: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
        if let nav = base as? UINavigationController {
            return topViewController(base: nav.visibleViewController)
        }
        if let tab = base as? UITabBarController {
            let moreNavigationController = tab.moreNavigationController

            if let top = moreNavigationController.topViewController, top.view.window != nil {
                return topViewController(base: top)
            } else if let selected = tab.selectedViewController {
                return topViewController(base: selected)
            }
        }
        if let presented = base?.presentedViewController {
            return topViewController(base: presented)
        }
        return base
    }
}

样品用法：

if let rootViewController = UIApplication.topViewController() {
     //do something with rootViewController
}

Answer 10

我经常需要检索当前显示的视图控制器。 它可能意味着视图控制器位于当前UINavigationController的堆栈顶部，当前呈现的视图控制器等。所以我编写了这个函数，它在大多数时候都能找到它，并且你可以在UIViewController扩展中使用它。

Swift 3中的代码：

func currentViewController(
_ viewController: UIViewController? =
    UIApplication.shared.keyWindow?.rootViewController)
        -> UIViewController? {
    guard let viewController =
    viewController else { return nil }

    if let viewController =
        viewController as? UINavigationController {
        if let viewController =
            viewController.visibleViewController {
            return currentViewController(viewController)
        } else {
            return currentViewController(
                viewController.topViewController)
        }
    } else if let viewController =
            viewController as? UITabBarController {
        if let viewControllers =
            viewController.viewControllers,
            viewControllers.count > 5,
            viewController.selectedIndex >= 4 {
            return currentViewController(
                viewController.moreNavigationController)
        } else {
            return currentViewController(
                viewController.selectedViewController)
        }
    } else if let viewController =
            viewController.presentedViewController {
        return viewController
    } else if viewController.childViewControllers.count > 0 {
        return viewController.childViewControllers[0]
    } else {
        return viewController
    }
}

用它来调用它： currentViewController()

Answer 11

如果有人想要目标 C。

全局管理器

//
//  GlobalManager.h
//  Communicator
//
//  Created by Mushrankhan Pathan on 21/10/21.
//  Copyright © 2021 Ribbideo. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface GlobalManager : NSObject

typedef void (^ ActionBlock)(void);

+(UIViewController*)currentController;
+(UIViewController*)currentController:(UIViewController*) baseController;

@end

NS_ASSUME_NONNULL_END

全球经理人

//
//  GlobalManager.m
//  Communicator
//
//  Created by Mushrankhan Pathan on 21/10/21.
//  Copyright © 2021 Ribbideo. All rights reserved.
//

#import "GlobalManager.h"

@implementation GlobalManager

+(UIViewController*)currentController
{
    UIViewController *base = UIApplication.sharedApplication.keyWindow.rootViewController;
    return [GlobalManager currentController:base];
}

+(UIViewController*)currentController:(UIViewController*) baseController
{
    if ([baseController isKindOfClass:[UINavigationController class]]) {
        return [GlobalManager currentController:((UINavigationController*)baseController).visibleViewController];
    }
    
    if ([baseController isKindOfClass:[UITabBarController class]]) {
        UINavigationController* moreNavigationController = ((UITabBarController*)baseController).moreNavigationController;
        UIViewController* top = moreNavigationController.topViewController;
        if (top.view.window != nil) {
            return [GlobalManager currentController:top];
        }
        UIViewController* selectedViewController = ((UITabBarController*)baseController).selectedViewController;
        if (selectedViewController != nil) {
            return [GlobalManager currentController:selectedViewController];
        }
    }
    
    if (baseController.presentedViewController != nil) {
        return [GlobalManager currentController:baseController.presentedViewController];
    }
    
    return baseController;
}

@end

如何使用。

UIViewController *currentVC = [GlobalManager currentController];