Scroll the Background so that the text fields are always visible (Swift 4)

UITextField.swift

/*
https://github.com/hackiftekhar/IQKeyboardManager
Extremely easy to install Swift or Objective-C.
Here how it works: 
IQKeyboardManager (Swift):- IQKeyboardManagerSwift is available through CocoaPods, to install it simply add the following line to your Podfile: (#236)
*/

// pod 'IQKeyboardManagerSwift'

//In AppDelegate.swift, just import IQKeyboardManagerSwift framework and enable IQKeyboardManager.

import IQKeyboardManagerSwift

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    IQKeyboardManager.sharedManager().enable = true

    return true
    }
}
//Now Reopen the project and Build and Run!