ios获取当前的导航控制器

话不多说，直接上代码吧

@interface UINavigationController (Extension)
+ (UINavigationController *)currentNC;
@end

@implementation UINavigationController (Extension)
+ (UINavigationController *)currentNC
{
    if (![[UIApplication sharedApplication].windows.lastObject isKindOfClass:[UIWindow class]]) {
        NSAssert(0, @"未获取到导航控制器");
        return nil;
    }
    UIViewController *rootViewController = [UIApplication sharedApplication].keyWindow.rootViewController;
    return [self getCurrentNCFrom:rootViewController];
}

//递归
+ (UINavigationController *)getCurrentNCFrom:(UIViewController *)vc
{
    if ([vc isKindOfClass:[UITabBarController class]]) {
        UINavigationController *nc = ((UITabBarController *)vc).selectedViewController;
        return [self getCurrentNCFrom:nc];
    }
    else if ([vc isKindOfClass:[UINavigationController class]]) {
        if (((UINavigationController *)vc).presentedViewController) {
            return [self getCurrentNCFrom:((UINavigationController *)vc).presentedViewController];
        }
        return [self getCurrentNCFrom:((UINavigationController *)vc).topViewController];
    }
    else if ([vc isKindOfClass:[UIViewController class]]) {
        if (vc.presentedViewController) {
            return [self getCurrentNCFrom:vc.presentedViewController];
        }
        else {
            return vc.navigationController;
        }
    }
    else {
        NSAssert(0, @"未获取到导航控制器");
        return nil;
    }
}
@end