I have a TableViewController which implements the TableViewDelegate methods:
public override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let cell = tableView.cellForRowAtIndexPath(indexPath) as! ParticipantesSearchTableViewCell
cell.viewModel?.active = true
}
public override func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
let cell = tableView.cellForRowAtIndexPath(indexPath) as! ParticipantesSearchTableViewCell
cell.selectedStateImageView.hidden = true
cell.viewModel?.active = false
}
Please note that I never remove nor set my tableView.editing to true. Also, my numberOfRowsInSection method never changes.
If I set my tableView to tableView.allowsSingleSelection = true I can select and deselect cells just fine and the above methods fire as aspected. However, when I scroll on my tableView and select a new cell the method didDeselectRowAtIndexPath crashes on let cell = tableView.cellForRowAtIndexPath(indexPath) as! ParticipantesSearchTableViewCell
At this point I debugged tableView.indexPathForSelectedRow and it returns nil.
Any idea what I'm implementing wrong here or if this is a bug? Because I try to use the same table with tableView.allowsMultipleSelection = true and I can select, deselect, and scroll just fine.
Related
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.
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
I have a UITableView.
I can select multiple cells make them highlighted.
But, whenever I reload App, the selected and highlighted state disappears.
I think I need to put some codes in 'viewDidAppear' and 'didSelectRowAt'. But I don't have any idea of specific codes.
What do I have to put in this syntax?
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
tableView.reloadData()
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
}
}
I recommend u add to dataSource item field selected, and in method cellForRowAtindexPath configure by your dataSource items.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cellClass = (self.cellClass(for: indexPath) ?? self.cellClasses.first) else { return UITableViewCell() }
let cell = tableView.dequeueReusableCell(withIdentifier: cellClass.identifier, for: indexPath)
if let configurable = cell as? ConfigurableComponent, let object = self.object(at: indexPath) {
let item = self.dataSource[indexPath.row]
configurable.selected = item.selected
}
return cell
}
When call didSelectRowAt, just take item and change selected field, sample:
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let item = self.dataSource[indexPath.row]
item.selected = !item.selected
tableView.reloadData()
}
I am making an app that requires the user to tap on multiple cells in order to select them. when they tap on a cell, a .Checkmark accessory item will appear. For some reason though whenever I try and get to that VC the app crashes and I get the following error messages on line 8(if !checked[indexPath.row]):
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
let cell: InstrumentTableCell! = tableView.dequeueReusableCellWithIdentifier(identifier) as? InstrumentTableCell
cell.configurateTheCell(recipies[indexPath.row])
if !checked[indexPath.row] {
cell.accessoryType = .None
} else if checked[indexPath.row] {
cell.accessoryType = .Checkmark
}
return cell
}
and this is my working checked method:
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
{
tableView.deselectRowAtIndexPath(indexPath, animated: true)
if let cell = tableView.cellForRowAtIndexPath(indexPath) {
if cell.accessoryType == .Checkmark {
cell.accessoryType = .None
checked[indexPath.row] = false
} else {
cell.accessoryType = .Checkmark
checked[indexPath.row] = true
}
}
}
Your problem is that you only store items in your checked array when tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) is called. However, that method is only called when you actually select a row.
tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) on the other hand is called each and every time you need to render a new table cell.
So when you in cellForRowAtIndexPath asks:
if !checked[indexPath.row]
then you can not be sure that checked actually contains anything. For instance the first time you start rendering your cells, your checked array does not contain any values and therefore it crashes when you ask it for a value on a position that it does not have a value for.
One solution could be to initialize your checked array to contain all false values. I'm guessing you have some model array called recipies so you could do something like:
for (index, _) in recipies.enumerate() {
checked.append(false)
}
Or as #AaronBrager suggests in the comments below (which is way prettier :))
checked = Array(count:recipies.count, repeatedValue:false)
that way you are sure that your checked array is properly initialized with the same number of elements as you have recipies.
Another option could be to let the individual elements in recipies know whether or not they are checked.
Hope this makes sense and helps you.
I have this piece of code:
tableView.deselectRowAtIndexPath(indexPath, animated: true)
if let selected = self.lastSelected {
tableView.cellForRowAtIndexPath(selected)?.accessoryType = .None
}
tableView.cellForRowAtIndexPath(indexPath)?.accessoryType = UITableViewCellAccessoryType.Checkmark
self.lastSelected = indexPath
I allows me to place a checkmark on the cell that I select and removes the previous checkmark. The problem I am having is that if the list is large and the cell is out of view, the checkmark is not removed when a new cell is selected.
I have tried adding tableview.reloaddata() but that did nothing.
Thoughts?
cellForRowAtIndexPath returns nil for non-visible cells.
To get a radio button like effect, you need to do something like this:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = UITableViewCell()
configureCell(cell, atIndexPath: indexPath)
return cell
}
func configureCell(cell: UITableViewCell, atIndexPath indexPath: NSIndexPath) {
if indexPath == selectedIndexPath {
cell.accessoryType = .Checkmark
} else {
cell.accessoryType = .None
}
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
selectedIndexPath = indexPath
// Note indexPathsForVisibleRows may be nil depending on your app's content.
// zip just joins two arrays together, into a single array of tuples.
zip(tableView.indexPathsForVisibleRows!, tableView.visibleCells).forEach({ indexPath, cell in
configureCell(cell, atIndexPath: indexPath)
})
}