UITableView返回空白单元格

Question

I have a table view with height of cells set to automatic. Once in a few runs, a few cells in the table are displayed empty (white space). Upon debugging, I noticed that the 'cellForRowAtIndexPath' function returns these cells as usual. Also, every time this bug shows up, the console has this message: "Warning once only: Detected a case where constraints ambiguously suggest a height of zero for a tableview cell's content view. We're considering the collapse unintentional and using standard height instead."

Scrolling up and down a couple of times fixes the issue and cells are displayed.

I use this following functions for height:

override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {

    return UITableViewAutomaticDimension

}

override func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {

    return UITableViewAutomaticDimension
}

I have been stuck with this for a week and any help would be greatly appreciated!

Edit : Code for the cells:

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

    return posts.count

}

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    var row = indexPath.row

    tableView.allowsSelection = false;

    let cellIdentifier = "testTableViewCell"

    let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! testTableViewCell

    let post: PostMdl!

    if(row < posts.count) {

        post = posts[row]

    }
    else {
        return cell
    }

    cell.label.delegate = self

    cell.label.enabledTextCheckingTypes = NSTextCheckingType.Link.rawValue

    cell.label.userInteractionEnabled = true

    cell.brandName.text = post.brandName

    cell.timeStamp.text = post.timeStamp

    cell.brandImg.sd_setImageWithURL(post.brandImgUrl, placeholderImage: UIImage(named: "placeHolder"))


    if let img = post.postImg {
        cell.mainImg.image = img

    } else {

        cell.mainImg.image = UIImage(named:"lazyLoad")

    }

    cell.label.text = post.postTag

    cell.labelDistanceFromImg.constant = 30

    cell.labelDistanceToBtm.constant = 30

    cell.postTag = post.postTag

    cell.socNtwkImg.image = UIImage(named: post.socNtwk)


    return cell
}

Answer 1

I guess you had set wrong constraints to subviews of UITableViewCell.contentView.

This image shows what I reproduce your error:

Please note the right constaints of red view, it just has Top Left Right Height , lacks bottom constraint, when I add it and it looks good:

Yes, there still have problem that Unable to simultaneously satisfy constraints , we can modify the priority of height constraint, default priority is required(1000), we change to Hight(750) , it works!

I don't know your cell's detail, but the error's reason is likely, hope my answer helps you.

Append codes

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

@IBOutlet var tableView: UITableView!
override func viewDidLoad() {
    super.viewDidLoad()
}

func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 10
}

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    return tableView.dequeueReusableCellWithIdentifier("cell")!;
}


func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}
}

Answer 2

What is your mobile phone version of the iOS? In the previous iOS8 version I also encountered similar problems. My method is as follows:

tableView.estimatedRowHeight = 88.0 tableView.rowHeight = UITableViewAutomaticDimension

Hope can help you