Set UITableView's height to the height of its content with Auto Layout

Question

I have a View which has two labels and a Table View inside it. I want label 1 to always stay above my Table View and label 2, to be below the Table View. The problem is that the Table View needs to auto-size meaning either increase in height or decrease.

Right now I have a constraint saying the Table View's height is always equal to 85 and a @IBOutlet to the height constraint where i'm able to change the constant.

I'm guessing I need to change the constant to the height of all the cells, but i'm not sure how.

Answer 1

You have to override updateViewConstraints() in your UIViewController and set the height constraint's constant to tableView.contentSize.height:

override func updateViewConstraints() {
    tableHeightConstraint.constant = tableView.contentSize.height
    super.updateViewConstraints()
}

Then you have to make sure that Label2 has a top constraint that is greaterThanOrEqual to the table view's bottom. And you also have to change the table view's height constraint's priority from Required to High to avoid conflicting constraints when the table view's contentHeight is larger than the available height.

Answer 2

There is another way to do that. You can add an observer on table view contentSize variable, and self size when change in table view content.

@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var tableHeightConstraint: NSLayoutConstraint!

override func viewDidLoad() {
    super.viewDidLoad()
    self.tableView.addObserver(self, forKeyPath: "contentSize", options: NSKeyValueObservingOptions.new, context: nil)
}
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    tableView.layer.removeAllAnimations()
    tableHeightConstraint.constant = tableView.contentSize.height
    UIView.animate(withDuration: 0.5) {
        self.updateViewConstraints()
    }

}

Answer 3

The below code worked for me.

1. Create an outlet for tableViewHeight.

@IBOutlet weak var tableViewHeight: NSLayoutConstraint!
var tableViewHeight: CGFloat = 0  // Dynamically calcualted height of TableView.

2. For the dynamic height of the cell, I used the below code:

func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
    return tableView.estimatedRowHeight
}

3. For height of the TableView, with dynamic heights of the TableView Cells:

func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
    print(cell.frame.size.height, self.tableViewHeight)
    self.tableViewHeight += cell.frame.size.height
    tableViewBillsHeight.constant = self.tableViewHeight
}

Explanation:

After the TableView cell is created, we fetch the frame height of the cell that is about to Display and add the height of the cell to the main TableView.

Answer 4

In Swift 4.2 and Xcode 10.1

Here you have two options to set height for UITableView based on content dynamically.

1) If you get content size use this code in viewDidLayoutSubviews()

DispatchQueue.main.async {
  var frame = self.TblView.frame
  frame.size.height = self.TblView.contentSize.height
   self.TblView.frame = frame
}

2) Based on table view height constraint update table view height. After got the response from server when reload table view write this code.

DispatchQueue.main.async {
    self.TblViewHeightConstraint.constant = CGFloat((self.array.count) * 30)//Here 30 is my cell height
     self.TblView.reloadData()
}

Answer 5

For TableView Height adjustment automatically with its content size use this in ViewController class.

//constraintTableViewHeight :- tableview height constraint 

override func viewWillLayoutSubviews() {
    super.updateViewConstraints()
    self.constraintTableViewHeight.constant = self.tableView.contentSize.height
}

and also add this

func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
    self.viewWillLayoutSubviews()
}

This code easily adjust tableview height automatically with its content size.

Answer 6

Extending @nova answer to swift 4

tableViewSizeObservation = tableView.observe(\.contentSize) { [weak self] (tableView, _) in
   tableView.layer.removeAllAnimations()
   self?.tableViewHeightContraint.constant = tableView.contentSize.height
   UIView.animate(withDuration: 0.5) {
         self?.view.updateConstraints()
         self?.view.layoutIfNeeded()
   }
}

deinit {
    tableViewSizeObservation?.invalidate()
}

Answer 7

A more modern way is doing this:

override func updateViewConstraints() {
    tableView.heightAnchor.constraint(equalToConstant: tableView.contentSize.height).isActive = true
    super.updateViewConstraints()
}

Answer 8

override func viewDidLayoutSubviews() {
      super.viewDidLayoutSubviews()      
           let contentheight = tableView.contentSize.height
           self.tableHeightConstraint.constant = contentheight
  }