UIScrollView is not scrolling after end of screen - ios

Question

I am trying to work with UIScrollView which I am adding programatically with auto layouts. I read other SO answers but none of them is working for me. My ScollView is scrolling but upto some point. After that end of the last child view is not showing. What i did was ,added a contentView to the UIScrollView and added subviews to the contentView. All the subviews are
translatesAutoresizingMaskIntoConstraints=false which is supposed t give me contentSize based on the constraints of the views but it is not. I tried locking the bottom of the contentView to the scrollview and also the bottom of the last subview of the contentview to the scrollview but it not working. Basically there are cards in the contentView which has height constraints. But they are not scrolling to the end. Last child is not scrolled to the end no matter what I do. What can be wrong with this approach?
class NodeSettingViewController: UIViewController,UIScrollViewDelegate {
var scrollView:UIScrollView?
var cellVM:NodeAppCellViewModel?
var contentView:UIView?
override func viewDidLoad() {
super.viewDidLoad()
let img = UIImage(named: "back_arrow")
let size = CGSize(width: 20, height: 20)
UIGraphicsBeginImageContext(size)
img!.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
let backButton = UIBarButtonItem(image: image, style: UIBarButtonItemStyle.plain, target: self, action: #selector(closeButtonTapped(_:)))
self.view.backgroundColor = UIColor.white
let appBar = MDCAppBarViewController()
appBar.headerStackView.backgroundColor = UIColor(netHex: Constants.color)
appBar.navigationBar.titleAlignment = .center
appBar.navigationBar.titleTextColor = UIColor.white
appBar.navigationBar.backItem = backButton
appBar.navigationBar.title = cellVM!.appName == nil ? "" : cellVM!.appName!
view.addSubview(appBar.view)
scrollView = UIScrollView()
scrollView!.translatesAutoresizingMaskIntoConstraints=false
contentView = UIView()
contentView!.backgroundColor = UIColor(netHex: Constants.BACKGROUUND_COLOR)
contentView!.translatesAutoresizingMaskIntoConstraints=false
let statusAndImageHolder = StatusAndImageHolderView()
statusAndImageHolder.translatesAutoresizingMaskIntoConstraints=false
statusAndImageHolder.setup(cellVM: cellVM)
contentView!.addSubview(statusAndImageHolder)
let healthCard = HealthCard()
healthCard.setShadowElevation(ShadowElevation.cardResting, for: UIControlState.normal)
healthCard.translatesAutoresizingMaskIntoConstraints=false
healthCard.setup(hubID: cellVM!.nodeApp!.hubId!, nodeID: cellVM!.nodeApp!.nodeId!,nApp: cellVM!.nodeApp)
let upperConstaintHealthCard = NSLayoutConstraint(item: healthCard, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: contentView!.subviews[contentView!.subviews.count-1], attribute: NSLayoutAttribute.bottom, multiplier: 1, constant:10)
let leftConstraintHealthCard = NSLayoutConstraint(item: healthCard, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: contentView, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let rightConstraintHealthCard = NSLayoutConstraint(item: healthCard, attribute: NSLayoutAttribute.right, relatedBy: NSLayoutRelation.equal, toItem: contentView, attribute: NSLayoutAttribute.right, multiplier: 1, constant: -10)
let heightConstraintHealthCard = NSLayoutConstraint(item: healthCard, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 150)
contentView!.addSubview(healthCard)
let additionalInfoCard = AdditionalInformationCard()
additionalInfoCard.translatesAutoresizingMaskIntoConstraints=false
additionalInfoCard.setShadowElevation(ShadowElevation.cardResting, for: UIControlState.normal)
additionalInfoCard.setup()
let upperConstaintAdditionalInfoCard = NSLayoutConstraint(item: additionalInfoCard, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: contentView!.subviews[contentView!.subviews.count-1], attribute: NSLayoutAttribute.bottom, multiplier: 1, constant:10)
let leftConstraintAdditionalInfoCard = NSLayoutConstraint(item: additionalInfoCard, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: contentView, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let rightConstraintAdditionalInfoCard = NSLayoutConstraint(item: additionalInfoCard, attribute: NSLayoutAttribute.right, relatedBy: NSLayoutRelation.equal, toItem: contentView, attribute: NSLayoutAttribute.right, multiplier: 1, constant: -10)
let heightConstraintAdditionalInfoCard = NSLayoutConstraint(item: additionalInfoCard, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 270)
contentView!.addSubview(additionalInfoCard)
let upperConstaintHolder = NSLayoutConstraint(item: statusAndImageHolder, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: contentView, attribute: NSLayoutAttribute.top, multiplier: 1, constant:0)
let leftConstraintHolder = NSLayoutConstraint(item: statusAndImageHolder, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: contentView, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 0)
let rightConstraintHolder = NSLayoutConstraint(item: statusAndImageHolder, attribute: NSLayoutAttribute.right, relatedBy: NSLayoutRelation.equal, toItem: contentView, attribute: NSLayoutAttribute.right, multiplier: 1, constant: -0)
let heightConstraintHolder = NSLayoutConstraint(item: statusAndImageHolder, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 150)
scrollView!.addSubview(contentView!)
scrollView!.bringSubview(toFront: contentView!)
self.view.addSubview(scrollView!)
let contentSize = UIScreen.main.bounds.size.width
let contentHeight = UIScreen.main.bounds.size.height-30
let upperConstaintScrollView = NSLayoutConstraint(item: scrollView!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: appBar.view, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 0)
let leftConstraintScrollView = NSLayoutConstraint(item: scrollView!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self.view, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 0)
let rightConstraintScrollView = NSLayoutConstraint(item: scrollView!, attribute: NSLayoutAttribute.right, relatedBy: NSLayoutRelation.equal, toItem: self.view, attribute: NSLayoutAttribute.right, multiplier: 1, constant: -0)
let bottomConstraintScrollView = NSLayoutConstraint(item: scrollView!, attribute: NSLayoutAttribute.bottom, relatedBy: NSLayoutRelation.equal, toItem: self.view, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: -0)
let upperConstaintContentView = NSLayoutConstraint(item: contentView!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: scrollView!, attribute: NSLayoutAttribute.top, multiplier: 1, constant: 0)
let leftConstraintContentView = NSLayoutConstraint(item: contentView!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: scrollView!, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 0)
let widthConstraintContentView = NSLayoutConstraint(item: contentView!, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentSize)
let heightConstraintContentView = NSLayoutConstraint(item: contentView!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentHeight)
NSLayoutConstraint.activate([upperConstaintScrollView,leftConstraintScrollView,rightConstraintScrollView,bottomConstraintScrollView,upperConstaintContentView,leftConstraintContentView,widthConstraintContentView,heightConstraintContentView,
upperConstaintHolder,leftConstraintHolder,rightConstraintHolder,heightConstraintHolder,
upperConstaintHealthCard,leftConstraintHealthCard,rightConstraintHealthCard,heightConstraintHealthCard,upperConstaintAdditionalInfoCard,leftConstraintAdditionalInfoCard,rightConstraintAdditionalInfoCard,heightConstraintAdditionalInfoCard])
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destination.
// Pass the selected object to the new view controller.
}
*/
#objc func closeButtonTapped(_ sender:Any){
self.dismiss(animated: true, completion: nil)
}
override func viewDidLayoutSubviews() {
scrollView?.isUserInteractionEnabled=true
scrollView!.isScrollEnabled=true
scrollView!.delegate=self
scrollView!.contentSize = contentView!.frame.size
}
}
I am sharing one of my card which is the last child of the subview.
class AdditionalInformationCard: MDCCard {
var titleLabel:UILabel?
var placeIdLabel:UILabel?
var eIDLabel:UILabel?
var hubIdLabel:UILabel?
var parentIDLabel:UILabel?
var deviceAddressLabel:UILabel?
var appIDLabel:UILabel?
var firmwareVersionLabel:UILabel?
var addedOnLabel:UILabel?
override func awakeFromNib() {
super.awakeFromNib()
}
func setup(){
let cardWidth = UIScreen.main.bounds.size.width-20
let contentWidth = cardWidth-20
titleLabel = UILabel()
titleLabel?.font = UIFont.boldSystemFont(ofSize: 18.0)
titleLabel?.textColor = UIColor(netHex: Constants.color)
titleLabel?.textAlignment = .left
titleLabel?.text = "Additional Information"
titleLabel?.translatesAutoresizingMaskIntoConstraints=false
self.addSubview(titleLabel!)
placeIdLabel = UILabel()
placeIdLabel?.textColor = UIColor.gray
placeIdLabel?.text = "Place Id"
placeIdLabel?.translatesAutoresizingMaskIntoConstraints=false
self.addSubview(placeIdLabel!)
eIDLabel = UILabel()
eIDLabel?.textColor = UIColor.gray
eIDLabel?.text = "eId"
eIDLabel?.translatesAutoresizingMaskIntoConstraints=false
self.addSubview(eIDLabel!)
hubIdLabel = UILabel()
hubIdLabel?.textColor = UIColor.gray
hubIdLabel?.text = "HUB Id"
hubIdLabel?.translatesAutoresizingMaskIntoConstraints=false
self.addSubview(hubIdLabel!)
parentIDLabel = UILabel()
parentIDLabel?.textColor = UIColor.gray
parentIDLabel?.text = "Parent Id"
parentIDLabel?.translatesAutoresizingMaskIntoConstraints=false
self.addSubview(parentIDLabel!)
deviceAddressLabel = UILabel()
deviceAddressLabel?.textColor = UIColor.gray
deviceAddressLabel?.text = "Device Address"
deviceAddressLabel?.translatesAutoresizingMaskIntoConstraints=false
self.addSubview(deviceAddressLabel!)
appIDLabel = UILabel()
appIDLabel?.textColor = UIColor.gray
appIDLabel?.text = "App Id"
appIDLabel?.translatesAutoresizingMaskIntoConstraints=false
self.addSubview(appIDLabel!)
firmwareVersionLabel = UILabel()
firmwareVersionLabel?.textColor = UIColor.gray
firmwareVersionLabel?.text = "Firmware Version"
firmwareVersionLabel?.translatesAutoresizingMaskIntoConstraints=false
self.addSubview(firmwareVersionLabel!)
addedOnLabel = UILabel()
addedOnLabel?.textColor = UIColor.gray
addedOnLabel?.text = "Added On"
addedOnLabel?.translatesAutoresizingMaskIntoConstraints=false
self.addSubview(addedOnLabel!)
let upperConstraintTitle = NSLayoutConstraint(item: titleLabel!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.top, multiplier: 1, constant: 5)
let leftConstraintTitle = NSLayoutConstraint(item: titleLabel!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let rightConstraintTitle = NSLayoutConstraint(item: titleLabel!, attribute: NSLayoutAttribute.right, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.right, multiplier: 1, constant: 10)
let heightConstraintTitle = NSLayoutConstraint(item: titleLabel!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 20)
let upperConstraintPlaceId = NSLayoutConstraint(item: placeIdLabel!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: titleLabel!, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 10)
let leftConstraintPlaceId = NSLayoutConstraint(item: placeIdLabel!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let widthConstraintPlaceId = NSLayoutConstraint(item: placeIdLabel!, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentWidth/2)
let heightConstraintPlaceId = NSLayoutConstraint(item: placeIdLabel!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 20)
let upperConstrainteId = NSLayoutConstraint(item: eIDLabel!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: placeIdLabel!, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 8)
let leftConstrainteId = NSLayoutConstraint(item: eIDLabel!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let widthConstrainteId = NSLayoutConstraint(item: eIDLabel!, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentWidth/2)
let heightConstrainteId = NSLayoutConstraint(item: eIDLabel!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 20)
let upperConstraintHubIdLabel = NSLayoutConstraint(item: hubIdLabel!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: eIDLabel!, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 8)
let leftConstraintHubIdLabel = NSLayoutConstraint(item: hubIdLabel!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let widthConstraintHubIdLabel = NSLayoutConstraint(item: hubIdLabel!, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentWidth/2)
let heightConstraintHubIdLabel = NSLayoutConstraint(item: hubIdLabel!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 20)
let upperConstraintParentIdLabel = NSLayoutConstraint(item: parentIDLabel!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: hubIdLabel!, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 8)
let leftConstraintParentIdLabel = NSLayoutConstraint(item: parentIDLabel!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let widthConstraintParentIdLabel = NSLayoutConstraint(item: parentIDLabel!, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentWidth/2)
let heightConstraintParentIdLabel = NSLayoutConstraint(item: parentIDLabel!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 20)
let upperConstraintDeiveAddressLabel = NSLayoutConstraint(item: deviceAddressLabel!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: parentIDLabel!, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 8)
let leftConstraintDeiveAddressLabel = NSLayoutConstraint(item: deviceAddressLabel!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let widthConstraintDeiveAddressLabel = NSLayoutConstraint(item: deviceAddressLabel!, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentWidth/2)
let heightConstraintDeiveAddressLabel = NSLayoutConstraint(item: deviceAddressLabel!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 20)
let upperConstraintAppId = NSLayoutConstraint(item: appIDLabel!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: deviceAddressLabel!, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 8)
let leftConstraintAppId = NSLayoutConstraint(item: appIDLabel!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let widthConstraintAppId = NSLayoutConstraint(item: appIDLabel!, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentWidth/2)
let heightConstraintAppId = NSLayoutConstraint(item: appIDLabel!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 20)
let upperConstraintFirmwareVersion = NSLayoutConstraint(item: firmwareVersionLabel!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: appIDLabel!, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 8)
let leftConstraintFirmwareVersion = NSLayoutConstraint(item: firmwareVersionLabel!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let widthConstraintFirmwareVersion = NSLayoutConstraint(item: firmwareVersionLabel!, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentWidth/2)
let heightConstraintFirmwareVersion = NSLayoutConstraint(item: firmwareVersionLabel!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 20)
let upperConstraintAddedOn = NSLayoutConstraint(item: addedOnLabel!, attribute: NSLayoutAttribute.top, relatedBy: NSLayoutRelation.equal, toItem: firmwareVersionLabel!, attribute: NSLayoutAttribute.bottom, multiplier: 1, constant: 8)
let leftConstraintAddedOn = NSLayoutConstraint(item: addedOnLabel!, attribute: NSLayoutAttribute.left, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.left, multiplier: 1, constant: 10)
let widthConstraintAddedOn = NSLayoutConstraint(item: addedOnLabel!, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: contentWidth/2)
let heightConstraintAddedOn = NSLayoutConstraint(item: addedOnLabel!, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 20)
NSLayoutConstraint.activate([upperConstraintTitle,leftConstraintTitle,rightConstraintTitle,heightConstraintTitle,
upperConstraintPlaceId,leftConstraintPlaceId,widthConstraintPlaceId,heightConstraintPlaceId,
upperConstrainteId,leftConstrainteId,widthConstrainteId,heightConstrainteId,
upperConstraintHubIdLabel,leftConstraintHubIdLabel,widthConstraintHubIdLabel,heightConstraintHubIdLabel,
upperConstraintParentIdLabel,leftConstraintParentIdLabel,widthConstraintParentIdLabel,heightConstraintParentIdLabel,upperConstraintDeiveAddressLabel,leftConstraintDeiveAddressLabel,widthConstraintDeiveAddressLabel,heightConstraintDeiveAddressLabel,
upperConstraintAppId,leftConstraintAppId,widthConstraintAppId,heightConstraintAppId,
upperConstraintFirmwareVersion,leftConstraintFirmwareVersion,widthConstraintFirmwareVersion,heightConstraintFirmwareVersion,upperConstraintAddedOn,leftConstraintAddedOn,widthConstraintAddedOn,heightConstraintAddedOn])
}
}