UIView's animate method not appearing - swift

Question

I am trying to make an app that utilizes some search feature and I am trying to make it so that after the search button is pressed, a view (which contains the search results) moves up from the bottom of the superview and replaces the search view. On the storyboard, the resultsView (of type UIView) is constrained so that its top is equal to the superview's bottom. After the search button is pressed, I would like to animate the view to move up and replace the view already at the bottom of the superview. The problem is, in the viewcontroller's class, when I call the resultsView, the animateWithDuration(NSTimeInterval) that is supposed to be associated with the UIView class is not appearing for me. May this be because the view is already constrained in place? Here is the code, simplified for this post:
import UIKit
import MapKit
class MapViewController: UIViewController, CLLocationManagerDelegate,
MKMapViewDelegate {
#IBOutlet weak var mapView: MKMapView!
#IBOutlet weak var slider: UISlider!
#IBOutlet weak var distanceLabel: UILabel!
#IBOutlet weak var searchButton: UIButton!
#IBOutlet weak var searchView: UIView!
#IBOutlet weak var resultView: UIView!
#IBOutlet weak var resultNameLabel: UILabel!
#IBOutlet weak var resultDistanceLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
mapView.delegate = self
self.resultView.isHidden = true
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func sliderAdjusted(_ sender: Any) {
let int = Int(slider.value)
switch int {
case 1:
distanceLabel.text = "1 mile"
default:
distanceLabel.text = "\(int) miles"
}
}
#IBAction func searchButtonPressed(_ sender: Any) {
/*This is where, after calling a search function which is omitted
from this example, I would like to make the resultsView not
hidden and then animate it to sort of eclipse the search view*/
self.resultView.isHidden = false
self.resultView.animate(withDuration: NSTimeInterval)
/*The above line of code is not actually appearing for me.
After typing "self.resultView." the animate function is not being
given to me as an option for my UIView*/
}
}
I will also attach some images of the view controller so you can sort of get the idea. The results view is not visible in this image because its top is constrained to the superview's bottom, thus it is just out of the visible representation of its superview.
The first image is the view controller with the searchView highlighted. This is the view that I would like to be eclipsed by my resultView after the searchButton is pressed.
The second image is the same view controller with the resultView highlighted. As you can see, its top is constrained to be equal to the superview's bottom. This is the view that I would like to animate upwards into the superview and eclipse the searchView after the search button is pressed.

Answer 1

The methods for all the animate family are all class methods. Which means you call them on the class object not an instance.
You are trying to call
class func animate(withDuration: TimeInterval, animations: () -> Void)
so your code needs to look like
UIView.animate(withDuration: 0.5) {
//the things you want to animate
//will animate with 0.5 seconds duration
}
In the particular case it looks like you are trying to animate the height of resultView so you need an IBOutlet to that constraint. You could call it resultViewHeight.
UIView.animate(withDuration: 0.5) {
self.resultViewHeight.constant = theDesiredHeight
self.layoutIfNeeded()
}
Calling layoutIfNeeded() within the closure is the secret sauce to animating auto layout. Without that the animation will just jump to the and point.