Swift - UITableViewCell 在更新 UILabel 文本时跳转

Question

When I update my UILabel text in my UITableViewCell like this:

self.label.text = "label text"

Everything works great....

But when I update my labels text from the Struct Array it causes the UITableView to sometimes jump when scrolling up to the top, not when scrolling down, but when I scroll towards the top...

Cannot understand why this happens....

Struct, data is being added from the results I get from the server

struct ContentStruct {
  var textLink : String? = ""
  var title : String? = ""
  var text : String? = ""
}

CellForRow

let postData = cellContentArray[(indexPath as NSIndexPath).section]

cell.binData(content: postData)

TableViewCell

 func binData(content: ContentStruct) {
    self.titleLabel.text = content.title
    self.text.text = "yytytytyt"//text
    self.uuidLabel.text = "yhhyhyhyyh"
   }

I am resizing the cell's like so: In the ViewDidLoad:

tableView.rowHeight = UITableViewAutomaticDimension

And then this:

 func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
    let height = self.heightAtIndexPath.object(forKey: indexPath)
    if ((height) != nil) {
        return CGFloat(height as! CGFloat)
    } else {
        return UITableViewAutomaticDimension
    }
}

func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
    let height = cell.frame.size.height
    self.heightAtIndexPath.setObject(height, forKey: indexPath as NSCopying)
}

Any ideas?

Thanks in advance!

Answer 1

I've found that jumps like that occur when your dynamic cell heights don't match with your estimated row height. Easiest fix is to have a fixed cell height, or to calculate the height individually per cell.