reloadData() of UITableView with Dynamic cell heights causes jumpy scrolling

by

To prevent jumping you should save heights of cells when they loads and give exact value in tableView:estimatedHeightForRowAtIndexPath:

Swift:

var cellHeights = [IndexPath: CGFloat]()

func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
    cellHeights[indexPath] = cell.frame.size.height
}

func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
    return cellHeights[indexPath] ?? UITableView.automaticDimension
}

Objective C:

// declare cellHeightsDictionary
NSMutableDictionary *cellHeightsDictionary = @{}.mutableCopy;

// declare table dynamic row height and create correct constraints in cells
tableView.rowHeight = UITableViewAutomaticDimension;

// save height
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
    [cellHeightsDictionary setObject:@(cell.frame.size.height) forKey:indexPath];
}

// give exact height value
- (CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSNumber *height = [cellHeightsDictionary objectForKey:indexPath];
    if (height) return height.doubleValue;
    return UITableViewAutomaticDimension;
}

More Related Contents:

  1. Multiple UILabels inside a self sizing UITableViewCell
  2. When should translatesAutoresizingMaskIntoConstraints be set to true?
  3. UITableView auto resizing row constraint breaking mysteriously on iPhone 6Plus
  4. Giving certain cells different background colors and borders?
  5. the last UITableViewCell don’t have a separating line
  6. Using Auto Layout in UITableView for dynamic cell layouts & variable row heights
  7. UIScrollView Scrollable Content Size Ambiguity
  8. How do I set the height of tableHeaderView (UITableView) with autolayout?
  9. Is it possible to obtain a dynamic table view section header height using Auto Layout?
  10. One timer per table view cell
  11. Autolayout is ignored in Custom UITableViewCell
  12. ios 8 Swift – TableView with embedded CollectionView
  13. How to detect one button in tableview cell
  14. Swift – How creating custom viewForHeaderInSection, Using a XIB file?
  15. Type ‘ViewController’ does not conform to protocol ‘UITableViewDataSource’
  16. Open UITableView edit action buttons programmatically
  17. How to get data from firebase in descending order of value?
  18. UITableView dynamic cell heights only correct after some scrolling
  19. When can I activate/deactivate layout constraints?
  20. Auto-layout: What creates constraints named UIView-Encapsulated-Layout-Width & Height?
  21. Moving views with constraints
  22. Class has no initializers Swift
  23. Swift tableView Pagination
  24. UITableViewCell with autolayout left margin different on iPhone and iPad
  25. UITableViewCell checkmark to be toggled on and off when tapped
  26. table header view height is wrong when using auto layout, IB, and font sizes
  27. Swift UITableView reloadData in a closure
  28. Pass multiple parameters to addTarget
  29. How to Set UITableViewCellStyleSubtitle and dequeueReusableCell in Swift?
  30. How to add a button with click event on UITableViewCell in Swift?

Leave a Comment