TableView - heightForRowAtIndexPath not being called

Question

After going through all of the other Stack Overflow forms, I have implemented a dynamic height for one of my cells as follows:

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

    if(indexPath.row == 1){
        var image : UIImage = maskRoundedImage(image: UIImage(named: "Temp_Profile.png")!, radius: 150)
        cell.imageView?.image = image
        return cell
    }
    cell.textLabel?.text = TableArray[indexPath.row]
    cell.backgroundColor = UIColor.init(colorLiteralRed: 0.56, green: 0, blue: 0.035, alpha: 1)
    cell.textLabel?.textColor = UIColor.white
    cell.textLabel?.font = UIFont(name: "Helvetica", size: 28)

    return cell
}
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    if  indexPath.row == 1 {
        return UITableViewAutomaticDimension * 3

    }
    return UITableViewAutomaticDimension
}

It seems pretty straightforward, but a debugging session is showing that heightForRowAtIndexPath is never being called. The View Controller is a UITableViewController and everything else works properly. Do any of you see any reason that this function is not being called?

Thank you for the help!

As mentioned below, UITableViewAutomaticDimension is not a value that should be used for arithmetic. returning UITableViewAutomaticDimension * 3 will have unpredictable effects. — GetSwifty, Feb 02 '17 at 16:18
Note that calling `heightForRowAt` can be expensive; you could also call `self.tableView.rowHeight = UITableViewAutomaticDimension` and `self.tableView.estimatedRowHeight = 72.0 //estimated, average value` in `viewDidLoad`. Se also eg here: https://www.appcoda.com/self-sizing-cells/ — koen, Feb 02 '17 at 16:22

score 18 · Accepted Answer · answered Feb 02 '17 at 15:55

18

In Swift 3, the signature is:

func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat

You have the old signature so it isn't recognized.

func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    if indexPath.row == 1 {
        return UITableViewAutomaticDimension * 3

    }
    return UITableViewAutomaticDimension
}

answered Feb 02 '17 at 15:55

rmaddy

314,917
42
532
579

3

For anyone who attempted to use UITableViewAutomaticDimension * 3, don't . It returns a -1 as just a signal to the tableView to make it default. Use an actual number – Code Wiget Feb 02 '17 at 16:11
1

It's very easy to end up with the old signatures for these methods when you're copying examples from elsewhere - as we all do!. In some cases, XCode will generate an error if Swift has moved on enough to make things invalid - but for cases like this you only get a warning. That's you shouldn't ignore those yellow triangles. Auto-complete should give you the correct signature, and then the rest of the function will most likely be OK. – Russell Feb 02 '17 at 16:42

score 16 · Answer 2 · answered May 30 '18 at 04:56

16

For me, I had to do this.

self.tableviewObj.delegate = self

So, don't forget to add delegate to self. Because heightForRowAtIndexparth is declared in delegate protocol.

answered May 30 '18 at 04:56

Narasimha Nallamsetty

1,215
14
16

yes, it worked after adding above code on viewDidLoad method. Thanks – user1090751 Jul 05 '21 at 05:26

nullLululi · Answer 3 · 2019-04-30T08:04:10.267

1

In my case, I have three controller A, B, C. A is base controller, B inherits from A, and C inherits from B. I set tableView delegate in A, and implement heightForRowAt function in B, and the problem occurred when i use C. I guess because the proxy assigned in A eventually points to C, so the method in B is not called.

edited Apr 30 '19 at 08:04

answered Apr 30 '19 at 07:58

nullLululi

194
1
7

If you have a NEW question, please ask it by clicking the [Ask Question](//stackoverflow.com/questions/ask) button. If you have sufficient reputation, [you may upvote](//stackoverflow.com/privileges/vote-up) the question. Alternatively, "star" it as a favorite and you will be notified of any new answers. – Johan Apr 30 '19 at 08:17
In that case, (me too), and I found the solution was to define a placeholder method call in the base class and then override it in the descendants. Then it gets called. – Paul Stevenson Jan 28 '20 at 05:11

score 0 · Answer 4 · answered Mar 16 '19 at 03:29

if you are inside a UITableViewController, just remember that the method has to be one that you need to override or the method name is wrong.

In my case I had NSIndexPath instead of IndexPath and it didn't match to the right method to be called

tableView(_ tableView: UITableView, heightForRowAt indexPath: NSIndexPath) -> CGFloat

when I corrected it to

tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat

xcode would prompt for insertion of the override keyword.

TableView - heightForRowAtIndexPath not being called

4 Answers4