contentView with UITableView not scrolling within UIScrollView

Question

I'm creating a simple "Create your Profile" with many fields. My view is not scrolling despite the content being larger than the size of the scroll view. I think part of the issue is the relationship between the contents inside the contentView. I wanted the cells inside of the table view to be dynamic so that I can add more information later and the scrolling would still preform. I set the scrollView delegate and tableView delegate to self in viewDidLoad()

I've looked at other answers and tried their implementations to no avail. I referenced Height of contentView of UIScrollView based on inside content using Storyboard, for instance.

To adjust the table view's content dynamically, I wrote the following:

 override func viewDidLayoutSubviews() {
        DispatchQueue.main.async {
            var frame = self.tableView.frame
            frame.size.height = self.tableView.contentSize.height
            self.tableView.frame = frame
            self.updateViewConstraints()

        }
    }

For constraints, my hierarchy is Super View > Scroll View > Content View > Elements.

Essentially, each element depends on it's upper neighbor and each have set heights. The exception is the TableView, whose height is not fixed, and will be stretched according to it's neighbor below it, the error label. The error label is then constrained to the bottom of the view. Here is a more visual representation.

Here is the actual result:

I think the issue is the Error Label's constraint to the Table View is not being updated, but is there something I'm not seeing here? Everything below the top bar should scroll.

DonMag · Accepted Answer

Here is a basic example, using a "self-sizing" table view. No need for heightForRowAt or explicit setting of .contentSize -- it's all handled by auto-layout and constraints.

With a couple rows (nothing scrolls):

With a couple more rows (still, nothing scrolls):

And now with enough rows the we need scrolling:

This is how it's setup in IB / Storyboard:

Here is the source code:

//
//  DaveViewController.swift
//
//  Created by Don Mag on 7/1/19.
//

import UIKit

final class ContentSizedTableView: UITableView {
    override var contentSize:CGSize {
        didSet {
            invalidateIntrinsicContentSize()
        }
    }
    override var intrinsicContentSize: CGSize {
        layoutIfNeeded()
        return CGSize(width: UIView.noIntrinsicMetric, height: contentSize.height)
    }
}

class DaveCell: UITableViewCell {
    @IBOutlet var theLabel: UILabel!
    @IBOutlet var theTextField: UITextField!
}

class DaveViewController: UIViewController {

    @IBOutlet var theTableView: ContentSizedTableView!
    @IBOutlet var theScrollView: UIScrollView!

    let theLabels: [String] = [
        "NAME",
        "COMPANY",
        "POSITION",
        "CITY, STATE",
        "EMAIL ADDRESS",
        "ADDTL EMAIL
ADDRESS",
        "WORK NUMBER",
        "CELL NUMBER",
    ]

    let thePlaceholders: [String] = [
        "your name",
        "e.g. Bizee Inc.",
        "e.g. Regional Manager",
        "e.g. Denver, Colorado",
        "name@email.com",
        "name@email.com",
        "(XXX) XXX-XXXX",
        "(XXX) XXX-XXXX",
    ]

    override func viewDidLoad() {
        super.viewDidLoad()

        theTableView.dataSource = self
        theTableView.delegate = self

        theTableView.isScrollEnabled = false

        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)

        // add a "Done" button to dismiss the keyboard
        let doneBtn = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(doneTapped))
        self.navigationItem.rightBarButtonItem = doneBtn
    }

    @objc private func doneTapped() {
        view.endEditing(true)
    }

    @objc private func keyboardWillShow(notification: NSNotification){
        guard let keyboardFrame = notification.userInfo![UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else { return }
        theScrollView.contentInset.bottom = view.convert(keyboardFrame.cgRectValue, from: nil).size.height
    }

    @objc private func keyboardWillHide(notification: NSNotification){
        theScrollView.contentInset.bottom = 0
    }

}

extension DaveViewController: UITableViewDataSource, UITableViewDelegate {

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return theLabels.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "DaveCell", for: indexPath) as! DaveCell

        cell.theLabel.text = theLabels[indexPath.row]
        cell.theTextField.placeholder = thePlaceholders[indexPath.row]

        cell.selectionStyle = .none

        return cell
    }

}

and here is the Storyboard source:

contentView with UITableView not scrolling within UIScrollView

Answers (1)

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