UITableView duplicate section header after updating row heights

Question

In my iOS app, I have a UITextView inside a tableview cell.

The UITextView and hence the cell height expands when the frame required for the text entered by user exceeds the current height of the cell.

In order to achieve the above, I am calling [tableView beginUpdates] followed by [tableView endUpdates] to reload the height for the cells.

The above is resulting duplicate section headers overlapping the expanded cell.

Is there a way to fix this without calling [tableView reloadData]?

Appended below is some relevant code:

When there is a text change, I verify if the text will fit in current text view, if not the cell is expanded to the new height:

- (void)textViewDidChange:(UITextView *)textView {

    CGFloat oldTextViewHeight = [(NSNumber *)[self.cachedTextViewHeightsDictionary objectForKey:indexPath] floatValue];

    CGFloat newTextViewHeight = [textView sizeThatFits:CGSizeMake(textView.frame.size.width, CGFLOAT_MAX)].height + CELL_HEIGHT_PADDING;

    if (newTextViewHeight > oldTextViewHeight ||
        (newTextViewHeight != oldTextViewHeight && oldTextViewHeight != TEXTVIEW_CELL_TEXTVIEW_HEIGHT)) {

        [self reloadRowHeights];

    }
}

- (void)reloadRowHeights {
    // This will cause an animated update of the height of the UITableViewCell
    [self.tableView beginUpdates];
    [self.tableView endUpdates];
}

It's also important to note that I am using a custom section header, which makes my problem similar to one mentioned here: UITableView Custom Section Header, duplicate issue

I cannot however use the solution to above problem because I cannot reloadData for the tableView in middle of user entering text.

Answer 1

Little late to the party, but I couldn't find a working solution on SO, and then I figured one out, so I thought I'd share.

I use UITableViewAutomaticDimension both for cell heights and for section header heights. My header view class is just a UIView subclass with some subviews as needed. Inside my tableView(:viewForHeaderInSection:) class, I just initialized a new header view as needed, and I was experiencing this duplicate headers issue. Not even reloadData helped.

What seems to have fixed it for me was to implement basic "cell re-use" for the headers. Something like this:

Store the header views in a dictionary somewhere in your view controller.

class ViewController: UIViewController {
   var sectionHeaders: [Int: UIView] = [:]
   // etc...
}

Then, upon request, return your existing section header view if available, or else create and store a new one.

func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
   if let sectionHeader = self.sectionHeaders[section] {
      return sectionHeader
   } else {
      let sectionHeader = YourSectionHeader()
      // Setup as needed...
      self.sectionHeaders[section] = sectionHeader
      return sectionHeader
   }
}