How can I move tableview section? - swift

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)

Related

Bug when reloading a certain row of a UTableView

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])

How to change editing style for specific cell in tableview

I have a tableview where the editingstyle is .delete for all the cells. But I want to have some specific cells that doesnt have editingstyle (so that you can't swipe them, .none). Anyone have any suggestions for how to implement this?
I tried to write something like UITableViewCell.EditingStyle.none for that specific row but that didnt work.
Thanks in advance, Pontus
Consider the following example:
class ViewController: UITableViewController {
private let arr = (1...10).map { "Item \($0)" }
override func viewDidLoad() {
super.viewDidLoad()
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return arr.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell")
cell?.textLabel?.text = arr[indexPath.row]
return cell ?? UITableViewCell()
}
override func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCell.EditingStyle {
if indexPath.row == 2 {//<- Your condition
return .none
} else {
return .delete
}
}
override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
}
So the key is to use editingStyleForRowAt in order to change the style for a specific cell (or even multiple cells) (see the documentation for further reference: https://developer.apple.com/documentation/uikit/uitableviewdelegate/1614869-tableview).

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

Deleting a row not working in UITableViewController

I have a dictionary that I have made called places and I made each cell in the tableViewController show each parts of the dictionary. I know the function to delete the rows in the controller, but when I run the app and do the action of deleting nothing happens.
// This is my entire TableViewController. I have another ViewController that appends the dictionary.
var places = [Dictionary<String,String>()]
var activePlace = -1
class TableViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
if UserDefaults.standard.object(forKey: "places") != nil { //checks if the list is not empty
places = UserDefaults.standard.object(forKey: "places") as! [Dictionary<String, String>]
}
if places.count == 1 {
places.remove(at: 0)
places.append(["name":"Ex. Eiffel Tower", "lat": "48.858324", "lon": "2.294764"])
}
}
// MARK: - Table view data source
override func tableView(_ tableView: UITableView, canEditRowAt
indexPath: IndexPath) -> Bool {
return true
}
override func numberOfSections(in tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return places.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
DispatchQueue.main.async {
self.tableView.reloadData()
}
cell.textLabel?.text = places[indexPath.row]["name"]
return cell
}
override func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? {
activePlace = indexPath.row
return indexPath
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "newPlace" {
activePlace = -1
}
}
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
tableView.deleteRows(at: [indexPath], with: .bottom)
places.remove(at: indexPath.row)
UserDefaults.standard.setValue(places, forKey: "places")
}
}
I am expecting that when I make the action of swiping to the left that it would delete the row and the contents of the cell from the tableView. Then it would also delete from the dictionary.
It's very complicate to delete table view cell sometimes. Your code is correct but you just need to remove a line. Instead of calling tableview.deleteRows you just delete the item of your dictionary and reload the table view.
Enable the table rows to editable using canEditRowAt function....
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
places.remove(at: indexPath.row)
UserDefaults.standard.setValue(places, forKey: "places")
tableView.reloadData()
}
}
Move deleteRows(at:with:) after remove(at:) in tableView(_: commit: forRowAt:) method, i.e.
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
places.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .bottom) //here...
UserDefaults.standard.setValue(places, forKey: "places")
}
}
The main issue is the wrong declaration of the data source array. The pair of parentheses must be behind the brackets
var places = [Dictionary<String,String>]()
In the method tableView(_:commit:forRowAt:the order is wrong. First remove the row from the data source array then delete the row.
Two Don'ts
Do not use setValue:forKey with UserDefaults to save a single value.
Do not declare the data source array outside of the class.
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
places.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .bottom)
UserDefaults.standard.set(places, forKey: "places")
}
}
Solved:
DispatchQueue.main.async was creating an endless loop of constantly reloading the data. By removing that the two functions of editing were allowed to run. I was able to perform the deleting action.

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.