获取当前所在的ViewController

- (UIViewController *)getCurrentVC {
    UIViewController *rootViewController = [UIApplication sharedApplication].keyWindow.rootViewController;
    UIViewController *currentVC = [self getCurrentVCFrom:rootViewController];
    return currentVC;
}

- (UIViewController *)getCurrentVCFrom:(UIViewController *)rootVC{
    UIViewController *currentVC;
    
    if ([rootVC presentedViewController]) {
        // 视图是被presented出来的
        rootVC = [rootVC presentedViewController];
    }
    
    if ([rootVC isKindOfClass:[UITabBarController class]]) {
        // 根视图为UITabBarController
        currentVC = [self getCurrentVCFrom:[(UITabBarController *)rootVC selectedViewController]];
    } else if ([rootVC isKindOfClass:[UINavigationController class]]){
        // 根视图为UINavigationController
        currentVC = [self getCurrentVCFrom:[(UINavigationController *)rootVC visibleViewController]];
    } else {
        // 根视图为非导航类
        currentVC = rootVC;
    }
    return currentVC;
}