iOS 获取当前视图控制器

- (UIViewController *)getCurrentVC {
    UIViewController *result = nil;

    UIWindow *window = [[UIApplication sharedApplication] keyWindow];
    if (window.windowLevel != UIWindowLevelNormal) {
        NSArray *windows = [[UIApplication sharedApplication] windows];
        for (UIWindow *temp in windows) {
            if (temp.windowLevel == UIWindowLevelNormal) {
                window = temp;
                break;
            }
        }
    }
    //取当前展示的控制器
    result = window.rootViewController;
    while (result.presentedViewController) {
        result = result.presentedViewController;
    }
    //如果为UITabBarController：取选中控制器
    if ([result isKindOfClass:[UITabBarController class]]) {
        result = [(UITabBarController *)result selectedViewController];
    }
    //如果为UINavigationController：取可视控制器
    if ([result isKindOfClass:[UINavigationController class]]) {
        result = [(UINavigationController *)result visibleViewController];
    }
    return result;
}