Bug when reloading a certain row of a UTableView - swift

I have a strange bug when I reload a certain row of UITableView via the .reloadRows() method.
Snippets of code:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return news_section.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell_section", for: indexPath) as! NewsSectionCell
cell.delegate_press_btn = self
var news_index = self.news_section[indexPath.row]
cell.number = news_index
cell.indexPath = indexPath
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
var highCell = self.needs_high_cell(news_sect: self.news_section[indexPath.row])
return highCell ? 150 : 90.0
}
The cell has a button when pressed via delegate does following:
self.news_section[index] = 0
self.news_table_view.reloadRows(at: [indexPath], with: .none)
Sometimes it works sometimes it produces this:
NSMutableRLEArray objectAtIndex:effectiveRange:: Out of bounds
I tried to change the cell number by changing the array from where the cell gets his number. And then reload only that row.

Use this code may be helpfull for you:---
let indexPath = IndexPath(item: rowNumber, section: 0)
tableView.reloadRows(at: [indexPath], with: .top)

For anybody looking for a similar problem :
// Reconfigures any existing cells for the rows. Reconfiguring is more efficient than reloading a row, as it does not replace the
// existing cell with a new cell. Prefer reconfiguring over reloading unless you actually need an entirely new cell for the row.
#available(iOS 15.0, *)
open func reconfigureRows(at indexPaths: [IndexPath])

Related

Textfield values deleted when scrolling tableview?

I have tableview cell with a textfield but when I add new row and scroll tableview up or down disappeared textfield values deleted. I make lots of research about that previous question about that in 2015 and its not answered correctly. How can I fix this issue? How can I use textfield delegate method if it is working for this? Here my code:
var i = 0
while i <= taskArrForRead.count {
let indexPath = IndexPath(row: i, section: 0)
let cell = self.tableView.cellForRow(at: indexPath) as? taslakDuzenlemeCell
if let item = cell?.taslakTextField.text! {
arrayOfNames.append(item)
}
i = i + 1
}
In this code I get all textfield values from tableview but if tableview scroll disappeared values turn with default values. How can I fix it? Thanks.
Here my tableview code:
extension taslakOlusturmaController: UITableViewDelegate, UITableViewDataSource, UITextFieldDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return taskArrForRead.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "taslakCell", for: indexPath) as! taslakDuzenlemeCell
cell.taslakTextField.text = taskArrForRead[indexPath.item]
cell.taslakTextField.delegate = self
return cell
}
func textFieldDidEndEditing(_ textField: UITextField) {
print(textField.text!)
self.arrayOfNames.append(textField.text!)
}
func tableView(_ tableView: UITableView, didEndDisplaying cell: UITableViewCell, forRowAt indexPath: IndexPath) {
let cell = tableView.dequeueReusableCell(withIdentifier: "taslakCell", for: indexPath) as! taslakDuzenlemeCell
cell.taslakTextField.text = taskArrForRead[indexPath.item]
print(arrayOfNames[indexPath.item])
}
}
With textfield delegate method I can get deleted textfield values but I can't bring it again to textfield. User can't see value after scroll again also I can get deleted values with didEndDisplaying cell method too.
You could use the method PrepareForReuse to set the text back when the cell recreated again.

Weird display behaviour when selecting tableview row

I have this table view, that populates through Core Data. Everything looks fine, even when scrolling, until I press and hold any row - then that row distorts like in the second image below.
(source: staticflickr.com)
(source: staticflickr.com)
Here's the code to display the tableview
override func viewDidLoad() {
super.viewDidLoad()
animateBackground(colors)
tableView.delegate = self
tableView.dataSource = self
tableView.fetchData(fetchedResultsController as! NSFetchedResultsController<NSFetchRequestResult>)
self.tableView.tableFooterView = UIView(frame: .zero)
}
func numberOfSections(in tableView: UITableView) -> Int {
guard fetchedResultsController.sections?.count != nil else { return 0 }
return fetchedResultsController.sections!.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
guard fetchedResultsController.sections != nil else { return 0 }
let data = fetchedResultsController.sections![section]
return data.numberOfObjects
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "SkillCell", for: indexPath) as! SkillCell
configureCell(cell: cell, indexPath: indexPath as NSIndexPath)
return cell
}
func configureCell(cell: SkillCell, indexPath: NSIndexPath) {
let skill = fetchedResultsController.object(at: indexPath as IndexPath)
cell.skill = skill
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) { }
}
From the code above, everything looks normal, yet this distortion occurs. Please help me to see why and how to stop it happening.
As the comment suggests, it's just a visual effect called selectionStyle of your UITableViewCell. Inside your cellForRowAt indexPath method, you can disable it like:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "myCell") as! MyCell
cell.selectionStyle = .none // this removes the effect.
return cell
}
yes you should set tableView selection style to none.
1.Select the tableview in storyboard in the right panel set selection style to none.
or
2.in your tableview cellforrow method set
tableView.selectionstyle = none

How to fix 'black background after deletion of one row"

If a row is deleted, tableView shows black area below cells, while tableView has white background color as with the cell view.
Look at this:
https://www.dropbox.com/s/55ssb73t0ngr9yj/screenshot.png?dl=0
After deleting a row (it can be any one of them, not necessarily the last one), suddenly, black area shows up, though I didn't change any constraint or height of the tableView. Also, behind tableView, there is nothing in this area other than the 'self.view' whose background is also white, and in front of table view, no view is positioned. (one view is there, but it is the size of the screen, so it cannot be black only for this area.)
extension ApptDetailViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return appt.places.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ApptDetailCell", for: indexPath) as! ApptDetailCell
cell.placeNumLabel.text = "Place \(indexPath.row + 1)"
cell.placeNameLabel.text = appt.places[indexPath.row]
return cell
}
}
extension ApptDetailViewController: UITableViewDelegate {
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 60
}
func tableView(_ tableView: UITableView, moveRowAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) {
let moveString = appt.places.remove(at: sourceIndexPath.row)
let moveBool = appt.reachedPlaces.remove(at: sourceIndexPath.row)
appt.places.insert(moveString, at: destinationIndexPath.row)
appt.reachedPlaces.insert(moveBool, at: destinationIndexPath.row)
print("appt.places: \(appt.places)")
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
// deletion occurred.
appt.places.remove(at: indexPath.row)
appt.reachedPlaces.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .right)
}
}
}
As per our comment discussion —You can debug your UI using the view heirarchy debugger. This helps pinpoint anomalies in your views.
Or try to change the tableview background color.

How can I move tableview section?

I am developing the application with swift. I stored the objection data named Categories. I've added the tableViewImage here and there is no problem here. I want to move the section of the tableview together with the cell, but it does not. The functions I wrote are below. Please help me.Thanks.
func tableView(_ tableView: UITableView, canMoveRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_tableview:UITableView, moveRowAtIndexPath sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath)
{
let temp = categories[sourceIndexPath.section]
categories[sourceIndexPath.section] = categories[destinationIndexPath.section];
categories[destinationIndexPath.section] = temp
}
func tableView(_ tableView: UITableView, shouldIndentWhileEditingRowAt indexPath: IndexPath) -> Bool {
return false
}
func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCellEditingStyle {
return .none
}
You can try using this method, assigning the position of the section you want to move and the place where you want it to be at the end:
table.moveSection(0, toSection: 1)
You could also try deleting the section in the IndexSet or appropriate position, subtracting in 1 the number of sections of the table and then reinserting the section and increasing the sections by 1
let index = IndexSet(integer: 0)
self.number_sections -= 1
table.deleteSections(index, with: .fade)
let newIndex = IndexSet(integer: 1)
self.number_sections += 1
table.insertSections(newIndex, with: .fade)

tableview persisting cell image after reloading

I have a tableview with cells that when selected displays an image within the selected cell, this image then disappears when the cell is selected again, and so on. When i press a submit button the selected cells are remembered and the tableview reloads with new data. But when doing this all the new data loads but the selected cell image persists. I have tried calling tableView.reloadData() on the main queue but it still persists. The image also persists when i press the submit button several times.
Heres my code:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return currentQuestion.answers.count
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return tableView.frame.height/CGFloat(currentQuestion.answers.count)
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
setSelectedArray()
let cell: AnswersTableViewCell = tableView.dequeueReusableCell(withIdentifier: "answersTableViewCell") as! AnswersTableViewCell
let text = currentQuestion.answers[indexPath.row]
let isAnAnswer = currentQuestion.answerKeys[indexPath.row]
cell.answerTextLabel.text = text
cell.answerView.backgroundColor = UIColor.white.withAlphaComponent(0.5)
cell.contentView.sendSubview(toBack: cell.answerView)
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if let cell: AnswersTableViewCell = tableView.cellForRow(at: indexPath) as? AnswersTableViewCell {
if cell.answerImageView.image == nil {
cell.answerImageView.image = UIImage(named: "paw.png")
selected[indexPath.row] = true
} else {
cell.answerImageView.image = nil
selected[indexPath.row] = false
}
}
}
#IBAction func submitButtonWasPressed() {
if questionNumber < questions.count - 1 {
questionNumber += 1
setCurrentQuestion()
self.answersTableView.reloadData()
self.view.setNeedsDisplay()
}
}
Any help would be great. Thanks
You need to set the image back to its correct value in cellForRow. Cells in your table are reused between calls to reloadData, and since you're not touching the imageView, it's keeping its previous value. Looks to me like you want:
cell.answerImageView.image = selected[indexPath.row] ? UIImage(named: "paw.png") : nil
inside of tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath).