获取当前ViewController

获取当前所在viewController适用于后台进入前台情况

#pragma mark - 得到当前所在viewController

-(UIViewController *)currentViewController

{

    UIWindow *keyWindow = [UIApplication sharedApplication].keyWindow;

    // modal展现方式的底层视图不同

    // 取到第一层时，取到的是UITransitionView，通过这个view拿不到控制器

    UIView *firstView = [keyWindow.subviews firstObject];

    UIView *secondView = [firstView.subviews firstObject];

    UIViewController *vc = [self getCurrentViewControllerByView:secondView];

    if ([vc isKindOfClass:[UITabBarController class]]) {

        UITabBarController *tab = (UITabBarController *)vc;

        if ([tab.selectedViewController isKindOfClass:[UINavigationController class]]) {

            UINavigationController *nav = (UINavigationController *)tab.selectedViewController;

            return [nav.viewControllers lastObject];

        } else {

            return tab.selectedViewController;

        }

    } else if ([vc isKindOfClass:[UINavigationController class]]) {

        UINavigationController *nav = (UINavigationController *)vc;

        return [nav.viewControllers lastObject];

    } else if([vc isKindOfClass:[MMDrawerController class]]){

        MMDrawerController *mmDrawer = (MMDrawerController*)vc;

        if ([mmDrawer.centerViewController isKindOfClass:[UINavigationController class]]) {

            UINavigationController *navC = (UINavigationController *)mmDrawer.centerViewController;

            return [navC.viewControllers lastObject];

        }else {

            UITabBarController *tabBar = (UITabBarController*)mmDrawer.centerViewController;

            UINavigationController *navC = (UINavigationController *)tabBar.selectedViewController;

            return [navC.viewControllers lastObject];

        }

    }else{

        return vc;

    }

    return nil;

}

#pragma mark - 根据view得到当前viewController

-(UIViewController *)getCurrentViewControllerByView:(UIView*)view{

    UIResponder *next = [view nextResponder];

    do {

        if ([next isKindOfClass:[UIViewController class]]) {

            return (UIViewController *)next;

        }

        next = [next nextResponder];

    } while (next != nil);

    return nil;

}