I am trying to make a list of contacts, and programmatically putting a star near each name where the family name is equal to a certain string, exactly like the picture below.
But in fact, the problem is that when this star appears on a certain cell, when scrolling down or up, nearly the other cells will also have the star appearing. (It's like coronavirus, spreading everywhere).
Is anyone able to help me fix this problem?
This is my code for the TableView:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let item = self.tableArray[indexPath.row]
let cell:SLF_LabelIconCell = tableView.dequeueReusableCell(withIdentifier: SLF_LabelIconCell.className) as? SLF_LabelIconCell ?? SLF_LabelIconCell()
//Add a star near favorite contacts
if item.familyName == "Zaghrini"{
cell.favoriteIcon.isHidden=false
}
return cell
}
At first glace, it appears correctly
But after scrolling up and down, more stars appears:
Try this:
if item.familyName == "Zaghrini" {
cell.favoriteIcon.isHidden = false
} else {
cell.favoriteIcon.isHidden = true
}
Why are you putting that in the cellForRowAt? Get it out of there. That should be for data only.
Use willDisplay instead.
Related
I have a table view with custom cells. They are quite tall, so only one cell is completely visible on the screen and maybe, depending on the position of that cell, the top 25% of the second one. These cells represent dummy items, which have names. Inside of each cell there is a button. When tapped for the first time, it shows a small UIView inside the cell and adds the item to an array, and being tapped for the second time, hides it and removes the item. The part of adding and removing items works fine, however, there is a problem related to showing and hiding views because of the fact that cells are reused in a UITableView
When I add the view, for example, on the first cell, on the third or fourth cell (after the cell is reused) I can still see that view.
To prevent this I've tried to loop the array of items and check their names against each cell's name label's text. I know that this method is not very efficient (what if there are thousands of them?), but I've tried it anyway.
Here is the simple code for it (checkedItems is the array of items, for which the view should be visible):
if let cell = cell as? ItemTableViewCell {
if cell.itemNameLabel.text != nil {
for item in checkedItems {
if cell.itemNameLabel.text == item.name {
cell.checkedView.isHidden = false
} else {
cell.checkedView.isHidden = true
}
}
}
This code works fine at a first glance, but after digging a bit deeper some issues show up. When I tap on the first cell to show the view, and then I tap on the second one to show the view on it, too, it works fine. However, when I tap, for example, on the first one and the third one, the view on the first cell disappears, but the item is still in the array. I suspect, that the reason is still the fact of cells being reused because, again, cells are quite big in their height so the first cell is not visible when the third one is. I've tried to use the code above inside tableView(_:,cellForRow:) and tableView(_:,willDisplay:,forRowAt:) methods but the result is the same.
So, here is the problem: I need to find an EFFICIENT way to check cells and show the view ONLY inside of those which items are in the checkedItems array.
EDITED
Here is how the cell looks with and without the view (the purple circle is the button, and the view is the orange one)
And here is the code for the button:
protocol ItemTableViewCellDelegate: class {
func cellCheckButtonDidTapped(cell: ExampleTableViewCell)
}
Inside the cell:
#IBAction func checkButtonTapped(_ sender: UIButton) {
delegate?.cellCheckButtonDidTapped(cell: self)
}
Inside the view controller (NOTE: the code here just shows and hides the view. The purpose of the code is to show how the button interacts with the table view):
extension ItemCellsTableViewController: ItemTableViewCellDelegate {
func cellCheckButtonDidTapped(cell: ItemTableViewCell) {
UIView.transition(with: cell.checkedView, duration: 0.1, options: .transitionCrossDissolve, animations: {
cell.checkedView.isHidden = !cell.checkedView.isHidden
}, completion: nil)
}
EDITED 2
Here is the full code of tableView(_ cellForRowAt:) method (I've deleted the looping part from the question to make it clear what was the method initially doing). The item property on the cell just sets the name of the item (itemNameLabel's text).
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell = tableView.dequeueReusableCell(withIdentifier:
ItemTableViewCell.identifier, for: indexPath) as? ItemTableViewCell{
cell.item = items[indexPath.row]
cell.delegate = self
cell.selectionStyle = .none
return cell
}
return UITableViewCell()
}
I've tried the solution, suggested here, but this doesn't work for me.
If you have faced with such a problem and know how to solve it, I would appreciate your help and suggestions very much.
Try this.
Define Globally : var arrIndexPaths = NSMutableArray()
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 30
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell:TableViewCell = self.tblVW.dequeueReusableCell(withIdentifier: "TableViewCell", for: indexPath) as! TableViewCell
cell.textLabel?.text = String.init(format: "Row %d", indexPath.row)
cell.btn.tag = indexPath.row
cell.btn.addTarget(self, action: #selector(btnTapped), for: .touchUpInside)
if arrIndexPaths.contains(indexPath) {
cell.backgroundColor = UIColor.red.withAlphaComponent(0.2)
}
else {
cell.backgroundColor = UIColor.white
}
return cell;
}
#IBAction func btnTapped(_ sender: UIButton) {
let selectedIndexPath = NSIndexPath.init(row: sender.tag, section: 0)
// IF YOU WANT TO SHOW SINGLE SELECTED VIEW AT A TIME THAN TRY THIS
arrIndexPaths.removeAllObjects()
arrIndexPaths.add(selectedIndexPath)
self.tblVW.reloadData()
}
I would keep the state of your individual cells as part of the modeldata that lies behind every cell.
I assume that you have an array of model objects that you use when populating you tableview in tableView(_:,cellForRow:). That model is populated from some backend service that gives you some JSON, which you then map to model objects once the view is loaded the first time.
If you add a property to your model objects indicating whether the cell has been pressed or not, you can use that when you populate your cell.
You should probably create a "wrapper object" containing your original JSON data and then a variable containing the state, lets call it isHidden. You can either use a Bool value or you can use an enum if you're up for it. Here is an example using just a Bool
struct MyWrappedModel {
var yourJSONDataHere: YourModelType
var isHidden = true
init(yourJSONModel: YourModelType) {
self.yourJSONDataHere = yourJSONModel
}
}
In any case, when your cell is tapped (in didSelectRow) you would:
find the right MyWrappedModel object in your array of wrapped modeldata objects based on the indexpath
toggle the isHidden value on that
reload your affected row in the table view with reloadRows(at:with:)
In tableView(_:,cellForRow:) you can now check if isHidden and do some rendering based on that:
...//fetch the modelObject for the current IndexPath
cell.checkedView.isHidden = modelObject.isHidden
Futhermore, know that the method prepareForReuse exists on a UITableViewCell. This method is called when ever a cell is just about to be recycled. That means that you can use that as a last resort to "initialize" your table view cells before they are rendered. So in your case you could hide the checkedView as a default.
If you do this, you no longer have to use an array to keep track of which cells have been tapped. The modeldata it self knows what state it holds and is completely independent of cell positions and recycling.
Hope this helps.
What I am trying to do is to replace borders(solid lines by default, of course) by small dots. I want the size of the dots to be 6 by 6.
Making borders invisible is a simple thing to do; I just set separators as 'None' in the attribute inspector.
But there was no field to set images or other objects as separators. To solve this problem, I splitted the dot into up and down pieces, assigned them in UIImageViews, and located the upper one on the bottom and the lower one on the top.
Then in the function tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath), I got the lower image in the first row and the upper image in the last row invisible.
What make the problem is that some unwanted dots disappear, while the dots I intended to change are properly gone away. Furthermore they come back or go away when the tableView is scrolled. The codes and the screenshot are below.
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cellIdentifier = "reuseIdentifier"
let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! MyListTableViewCell
//each element in datas[] has lowercase alphabets, a from q.
let array = datas[indexPath.row]
//data is a UIButton, which is the only component in each row besided those dots
cell.data.setTitle(array, forState: .Normal)
//this is where I typed to handle the unwanted dots on the very top and bottom
if indexPath.row == 0{
cell.lowerHalf.hidden = true
}
else if indexPath.row == datas.count - 1{
cell.upperHalf.hidden = true
}
///////////////////
return cell
}
When I scrolled tableView up and down side, it changed to this:
What makes the dots which shouldn't disappear go away? Or is their a better way to set images as borders?
+In the way iSashok suggested, things didn't change unfortunately. I applied this code right after the declaration; and then I moved to right before the return statement. Both did not work.
cell.clipsToBound = false
Your cell is getting reuse so you need to change your if condition of cellForRowAtIndexPath like this
if indexPath.row == 0 {
cell.lowerHalf.hidden = true
cell.upperHalf.hidden = false
}
else if indexPath.row == datas.count - 1{
cell.lowerHalf.hidden = false
cell.upperHalf.hidden = true
}
else {
cell.lowerHalf.hidden = false
cell.upperHalf.hidden = false
}
Try to modify for your cell clipsToBounds property in
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
like below
cell.clipsToBounds = false;
and for contentView the same
cell.contentView.clipsToBounds = false;
Why don't you use UITableViewHeaderFooterView? Simply create your view with that dot image in centre and return that view from viewForFooterInSection.
I have to make a view as image is below. I am confused and not able to darw Screen as Screen will have more Image on Bottom of Image as User will scroll the View and data on the Each time will come up Dynamically and Will on every time View Come up. Thanks any Help Appricated
after a long Research for this kind of view Finally i got a Solution Which is
take a Table View
take multiple Prototype Cell as much you Want
Set the Identifier Individually of each cell
create a Subcalss of UITableViewCell
Method like callForRowatindexPath you have to call like That with Diffrent Cell
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if indexPath.row == 0 {
var cell = tableView.dequeueReusableCellWithIdentifier(kCellIdentifier) as? specificTopicTableViewCell`cell.textlabel.text = "Hello"
return cell!
}
else {
let cell2 = tableView.dequeueReusableCellWithIdentifier(kSecCellIdentifier) as? scondTopicTableViewCell
cell2.textlabel.text = "Hello"
return cell2!
}
}
I have a tableView where I want to display different Cells depending on what a variable seguedDisplayMonth is set to. Is this possible and if so can I get any hint on how to do this? I've tried the following but it doesn't seem to work.
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Income Cell", forIndexPath: indexPath)
let income = myIncomeArray[indexPath.row]
if seguedDisplayMonth == "All" {
var text = "\(income.money) kr"
cell.textLabel?.text = text
cell.detailTextLabel?.text = income.name
}
return cell
}
I also thought that maybe I need to reload the data after changing the seguedDisplayMonth which gets changed from a different tableView and through a segue.
Call mcTableSwag.reloadData() once seguedDisplayMonth is changed. (Likely call it in the function that actually changes seguedDisplayMonth.
Alternatively you could reload certian cells with some method like reloadVisibleCellsAtIndexPath(...) (Im not sure what it is called exactly, but it should be on the Apple UITableView documentation.
I managed to fix it finally. I will explain how I did it incase anyone runs into the same problem.
I implemented another array myVisibleIncomeArray.
In viewDidLoad() I called a function which does the following:
for inc in myIncomeArray {
if self.monthLabel.text == "All" {
self.myVisibleIncomeArray.append(inc)
totalSum += inc.money
print("Added to myVisible")
}
}
Then I reloadData() and use myVisibleIncomeArray for the other functions.
Not sure if it was the smartest fix, but it's a fix nonetheless.
I'm trying to create an autocompleter using iOS 8, Swift and Xcode 6.3
I have a problem that I'm trying to solve, but I gave up... I hope someone can help here. The problem is that (custom) UITableViewCell's are not displaying when the initial dataSource is empty. When adding data to datasource and reloading the tableView, the cells SHOULD display, but they don't... At least, the first time they don't... A second time, they DO... When I initialize the table with non-empty data, the problem doesn't occur. I guess something goes wrong with dequeueReusableCellWithIdentifier. In beginning, no reusable cells are found, or something. But I don't know why...
Relevant code, in ViewController.swift:
// filteredWords is a [String] with zero or more items
#IBAction func editingChanged(sender: UITextField) {
autocompleteTableView.hidden = sender.text.isEmpty
filteredWords = dataManager.getFilteredWords(sender.text)
refreshUI()
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell") as! AutocompleteTableViewCell
cell.title.text = filteredWords[indexPath.row]
return cell
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return filteredWords.count
}
func refreshUI() {
self.autocompleteTableView.reloadData()
}
I created a sample project on github:
https://github.com/dirkpostma/swift-autocomplete
And a movie on YoutTube to show what goes wrong:
https://www.youtube.com/watch?v=ByMsy4AaHYI
Can anyone look at it and spot the bug...?
Thanks in advance!
You've accidentally hidden your cell.
Open Main.storyboard
Select Cell
Uncheck Hidden
Side note: As for why it's displaying the second time around with the cell hidden? It appears to be a bug. It should still be hidden (print cell.hidden, notice it's always true despite showing the text on the screen).
I think you need to change your code. Check out below code. It is because if you remember in Objective C you needed to check if the Cell was nil and then initialise it. The reuse identifier is usually reusing an already created cell, but on the first launch this does not work because there is no Cell to use. Your current code assumes always that the cell is created (re-used) because you are using ! in the declaration, so if you use the optional (?) it can be null and you then can create the cell
var cell = tableView.dequeueReusableCellWithIdentifier("Cell") as? AutocompleteTableViewCell
if cell == nil
{
//You should replace this with your initialisation of custom cell
cell = UITableViewCell(style: UITableViewCellStyle.Value1, reuseIdentifier: "CELL")
}
cell.title.text = filteredWords[indexPath.row]
return cell