I am currently learning IOS. I have UITableView embedded in NavigationController and UITabBar. I have populated the TableView with data and its showing in the table when I run the app. The TableView is not scrolling and for the life of me I can't figure out why.
Here is the table view code
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
return petitions.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
// code to initialize the cell here
return cell
}
Any suggestions as to what am missing, or how to make it work is welcomed
Maybe if you changed your table view scroll options. So table view is a scroll view. Options must be like below:
Related
I put my UITableView in UIScrollView > View > StackView.
And I implemented table view in View Controller as usual with numberOfRowsInSection and cellForRowAt. Here's my extension.
extension OrderViewController: UITableViewDataSource, UITableViewDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print("DEBUG: orderItems.count - \(orderItems.count)")
return orderItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: OrderCell.id, for: indexPath) as! OrderCell
cell.configure(orderItems[indexPath.row])
return cell
}
}
But my simulator actually shows empty cells. I already checked the orderItems array only has 2 members.
I guess it is because either auto layout or stack view. In the stack view, I gave height constraints for every views except table view since it has to have dynamic cell number.
I don't know what I have to change.
table view's attribute
This is because your tableview has full height with related your view. Just add on viewDidLoad
yourTableView.tableFooterView = UIView()
But if you want dynamic height for your tableview then do that;
Give a height constraint for your tableview
Create an IBOutlet for this constraint
After you reload your tableview
heightConstraint.constant = yourRowHeight * arrayCount
self.view.layoutIfNeeded()
I am trying to delete row from UITableView by using trailingSwipeActionsConfigurationForRowAt function.
The row gets deleted and disappears. This part is ok.
But next rows that are coming to the screen or when I swipe down the same amount as the rows been deleted are not even loaded on the tableView.
![img1]https://poirot.deus4.com/photo_2019-06-12_16-44-01.jpg
![img2]https://poirot.deus4.com/photo_2019-06-12_16-43-56.jpg
![img3]https://poirot.deus4.com/photo_2019-06-12_16-43-49.jpg
![img4]https://poirot.deus4.com/photo_2019-06-12_16-43-38.jpg
[video]https://poirot.deus4.com/RPReplay_Final1560345600.mp4
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return filteredProducts.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: .cellID, for: indexPath) as! ProductTableCell
cell.backgroundColor = .red
return cell
}
override func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let hide = UIContextualAction(style: .destructive, title: "Hide") { action, view, completion in
self.filteredProducts.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .automatic)
completion(true)
}
hide.image = #imageLiteral(resourceName: "hdie_product")
hide.backgroundColor = .midGrey
let conf = UISwipeActionsConfiguration(actions: [hide])
return conf
}
The code you showed obviously works, thus the problem is elsewhere.
Without other code I suspect that the problem is because table view cells are re-used: When you scroll your table view, some cells are scrolled out of view and can be reused. Cells that are scrolled in are either re-used cells or new cells.
In any case, the table view datasource function tableView(_:cellForRowAt:) must be used to configure the displayed cells.
It seems too me that you do not configure the cells in tableView(_:cellForRowAt:).
If so, re-used cells look as the were when they have been scrolled out, but new cells are simply blank.
So I suggest to check if you really configure all the cells in tableView(_:cellForRowAt:) correctly.
The issue was that I did not call super.prepareForReuse() inside TablewViewCell
override func prepareForReuse() {
super.prepareForReuse() // this was missing
}
I've searched around and haven't truly found why this is happening. Basically, I followed this tutorial https://www.youtube.com/watch?v=yupIw9FXUso by Jared Davison on creating Table View Cells to Multiple View controllers. In his example, everything works perfectly, but for some reason when you click on a table view cell in my code the cell is highlighted in grey. Then, when the user clicks on a separate table view cell the view controller that should have been loaded by the first table view cell is loaded. If the user then clicks back on the original table view cell the page that should have been loaded by the second table view cell is loaded. In summary, all of the view controllers are loaded a "click" behind.
Here is the code for the table view:
//Feed Navigation Functions
public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return elements.count
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 75
}
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "feedCell") as! FeedTableViewCell
cell.txtTitle.text = "The Fight Against \(elements[indexPath.row])"
cell.issueIcon.image = UIImage(named: "Issue Icons_\(elements[indexPath.row])")
return cell
}
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
let vcName = identities[indexPath.row]
let viewController = storyboard?.instantiateViewController(withIdentifier: vcName)
self.navigationController?.pushViewController(viewController!, animated: true)
}
Update: The array is a simple array of strings for example [One, Two, Three] there are 6 strings in the array.
When you select a cell then select another one the method didDeselectRow is called so the Vc is pushed you actually want to implement didSelectRowAt
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let vcName = identities[indexPath.row]
let viewController = storyboard?.instantiateViewController(withIdentifier: vcName)
self.navigationController?.pushViewController(viewController!, animated: true)
// this to deSelect it after push
tableView.deselectRow(at: indexPath, animated: false)
}
This method fired when a cell is selected
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath
This method fired when a cell is deSelected
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath
You want to use the tableView's delegate method didSelectRow instead of didDeselectRow I think...
Issue: click on a table view cell in my code the cell is highlighted in grey
This is due to the selectionStyle, which you can read about here. If you don't want the cell highlighted, you can set cell.selectionStyle = .none.
Edit: As indicated in other correct response - issue was with incorrect/typo in method - we should use didSelectRowAt not didDeselectRowAt.
Loading all the date from the firebase to the tableview at a time but i wanted to load 10 items at a time when i scroll to bottom again 10 items should load to the tableview, below is my code
extension ViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return items.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let item = items[indexPath.row]
let cell = tableView.dequeueReusableCell(withIdentifier: "inciCell") as!
IncidentCell
cell.delegate = self
cell.setupCell(with: item, indexPath)
return cell
}
}
In the delegate method cellForRowAtIndexPath you may check something like indexPath.row == items.count - 1.
if it's true, then you get 10 items from your DB and append it to your `items.
then do tableView.reloadData() to update the table view with 10 new items.
You may also make some nice spinner in the bottom (tableFooterView) of the table view. But it could be the next step.
Hope it helps.
Requirement :
I have a list of UITableviewCell loaded from a nib that I'm presenting on UITableview. The first time I open the UIViewController all cells are shown correctly and work as expected.
Issue :
If I navigate back to the parent and then open the UIViewController again the UITableviewCell are 'invisible'. I say invisible because with a breakpoint in cellForRowAt I can see that the table view does load all cells and the cells are valid.
Code :
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 13
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 40
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = (project?.sliderData.sliders[indexPath.row].view)! as UITableViewCell
print(cell.contentView.subviews.count)
if let left = cell.viewWithTag(2) as? UILabel {
left.text = "left"
}
if let middle = cell.viewWithTag(3) as? UILabel {
middle.text = "middle"
}
if let right = cell.viewWithTag(4) as? UILabel {
right.text = "right"
}
return cell
}
Screen Shot Image
Expected observation :
I was thinking that maybe the subviews of the cells get released because I don't have any bindings to them in IB. To test this I'm printing the count of subviews and writing some text to the subview labels. And everything seems to go fine, the cells are loaded and the labels are there but the cells just don't show up.
But then, if I scroll the TableView up and down a little to get some cells updated those cells do appear at the top and bottom of the view as shown in the pic.
You need to call dequeueReusableCell(withIdentifier: "cell") inside your code then will show your table cell. It will reuse cell for your all numbers of row data content.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell") as! UITableViewCell
return cell
}
More Details : How to create uitableview with multiple sections in iOS Swift.
Did not find reason why the tableView behaves the way it does so I solved the issue by dequeueing default cells. The views provided by the slider objects are added as subviews to the dequeued cells. Now the subviews can of course be any UIViews.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCell(withIdentifier: "sliderCell")
if cell == nil {
cell = UITableViewCell.init(style: .default, reuseIdentifier: "sliderCell")
}
cell?.addSubview((project?.sliderData.sliders[indexPath.row].view)!)
return cell!
}