Hiding the tabbar and removing the space

Programmatically, add this to the next view controller for swift 4.

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    tabBarController?.tabBar.isHidden = true
    edgesForExtendedLayout = UIRectEdge.bottom
    extendedLayoutIncludesOpaqueBars = true
}

And add a background color

Swift 3:

extension UITabBarController {
    func setTabBarVisible(visible:Bool, duration: TimeInterval, animated:Bool) {
        if (tabBarIsVisible() == visible) { return }
        let frame = self.tabBar.frame
        let height = frame.size.height
        let offsetY = (visible ? -height : height)

        // animation
        UIViewPropertyAnimator(duration: duration, curve: .linear) {
            self.tabBar.frame.offsetBy(dx:0, dy:offsetY)
            self.view.frame = CGRect(x:0,y:0,width: self.view.frame.width, height: self.view.frame.height + offsetY)
            self.view.setNeedsDisplay()
            self.view.layoutIfNeeded()
        }.startAnimation()
    }

    func tabBarIsVisible() ->Bool {
        return self.tabBar.frame.origin.y < UIScreen.main.bounds.height
    }
}

To use (if for example self is a UITabBarController):

self.setTabBarVisible(visible: false, duration: 0.3, animated: true)

Swift 2.x:

extension UITabBarController {
    func setTabBarVisible(visible:Bool, duration: NSTimeInterval, animated:Bool) {
        if (tabBarIsVisible() == visible) { return }
        let frame = self.tabBar.frame
        let height = frame.size.height
        let offsetY = (visible ? -height : height)

        // animation
        UIView.animateWithDuration(animated ? duration : 0.0) {
            self.tabBar.frame = CGRectOffset(frame, 0, offsetY)
            self.view.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height + offsetY)
            self.view.setNeedsDisplay()
            self.view.layoutIfNeeded()
        }
    }

    func tabBarIsVisible() ->Bool {
        return self.tabBar.frame.origin.y < UIScreen.mainScreen().bounds.height
    }
}

To use:

self.tabBarController?.setTabBarVisible(visible: false, duration: 0.3, animated: true)

If you're still seeing a black stripe under your hidden tab bar, have you tried to select Extend Edges Under Opaque Bars here?

Make also sure that Under Bottom Bars is still selected. Hope it helps!

After saw your screenshot in comment. I think you can try to set hidesBottomBarWhenPushed to true.

hidesBottomBarWhenPushed = true

Or storyboard.

It will hide bottom bar automatically when you pushed to another view controller, and appear it again when you go back.