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:
So I have 2 Views that are shown inside a UIView, based on what is selected on the SegmentViewController. I create dummy data, returning 20 row of a custom cell. This works great.
Everything is fine, till I interact with the TableView.
Bellow is my code:
GoalsViewController.swift
import UIKit
class GoalsViewController: UIViewController {
#IBOutlet weak var goalsTableView: UITableView!
let goalCellIdentifier = "goalCell"
override func viewDidLoad() {
super.viewDidLoad()
goalsTableView.delegate = self
goalsTableView.dataSource = self
goalsTableView.register(UINib(nibName: "GoalsViewCell", bundle: nil), forCellReuseIdentifier: goalCellIdentifier)
goalsTableView.reloadData()
}
}
extension GoalsViewController: UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 20
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = goalsTableView.dequeueReusableCell(withIdentifier: goalCellIdentifier, for: indexPath) as! GoalsViewCell
cell.goalTitle.text = "aaaaa"
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print("Selected \(indexPath.row)")
}
}
After any of the empty rows is selected, the didSelectRowAt is not called, so the cells are not there at all. I tried to find a solution, but I was only to find issues about empty lists, before being populated.
What could be the reason for the empty tableview?
I might be wrong here but one thing that I've noticed is that you are not implementing a function which sets the height of each cell.
// Specify the height of your cells
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100 // Or your given cell height.
}
So here is my theory: If you are using constraints something is missing and your cell's height can't be identified by constraints alone or you are not using constraints at all thus you must use heightForRowAt function to specify each cell's height.
I will explain what was the issue for people who probably did not know (like me).
So my UITableView is inside a UIView that changes based on what the user is selecting. In total I had 2 different Views that where switching. The reason that it was emptying it was because my parent ViewController, could not access the delegate for UITableView. To fix that, after adding a subview to the UIView, you need also to move the ViewController to the parent controller. In code it goes like this.
// Empty array of UIViewControllers
var views: [UIViewController]!
// Add the UIViewControllers to the array
views = [UIViewController()]
views.append(EventsViewController())
views.append(GoalsViewController())
for view in views {
// Needed to adjust the size of Subview to size of View
view.view.frame = containerView.bounds
// Add the subviews
containerView.addSubview(view.view)
}
// Bring the view in position 1 to the front of the UIView
containerView.bringSubviewToFront(views[1].view)
// Add Views[1] UIViewController as a child to the parent controller
self.addChild(views[1])
views[1].didMove(toParent: self)
// After done with everything with the UIViewController remove it
views[1].removeFromParent()
addChild Apple.com
didMove Apple.com
I am reloading table view every 0.25 seconds as I have a timer app, but the delete button when I swipe from right to left won't stay there because I am reloading the table view.
How do I fix this?
There is no need to reload the tableView to update the visible cells. Instead, loop over the visible cells calling the update method on each one:
// Example custom cell class
class MyCustomCell: UITableViewCell {
func updateTimeLabel() {
// code to update time label
}
}
In the timer method:
for case let cell as MyCustomCell in tableView.visibleCells {
cell.updateTimeLabel()
}
Your updateTimeLabel method might need data such as the current Date or the new value for the time label, so pass it what it needs to update the label.
a start of solution could be to observe swipe events on tableview thanks to :
optional func tableView(_ tableView: UITableView, willBeginEditingRowAtIndexPath indexPath: NSIndexPath)
in this func you stop the reload func
and in :
optional func tableView(_ tableView: UITableView, didEndEditingRowAtIndexPath indexPath: NSIndexPath)
you restart your reload func
I'm having this strange issue in my app where it sometimes takes several seconds (10ish) for a custom TableViewCell to trigger a segue to another ViewController. If I click anywhere else in the app during this time, the click triggers the segue.
The problem only occurs when selecting the same cell several times. Meaning if you click the first cell, segue over to the new ViewController, exit the new ViewController and click the same cell again, the problem could occur.
I've reconstructed this issue in a small project here for any kind souls to try out.
http://www.filedropper.com/customcellsegue_2
Any ideas guys?
Edit
Alright here's some code for you guys who don't wanna download the app.
Original ViewController
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 100.0
}
// Number of cells in each section.
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 2
}
// Fill UITableView...
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! UITableViewCell
return cell
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
println("Selected")
}
Custom Table Cell
class customCell: UITableViewCell {
#IBOutlet var firstLabel: UILabel!
#IBOutlet var secondLabel: UILabel!
}
New ViewController
#IBAction func close(sender: AnyObject) {
self.dismissViewControllerAnimated(true, completion: nil)
}
I've simply applied a modal segue from the custom cell to the new ViewController.
New to IOS development and am having trouble with handling cell selection on a table. Whenever I select, the method is not getting called below - any idea why?
My project structure is:
View Controller -> View -> Table View
The below code demonstrates the method calls. The others get called no problem! I know touch is working as pull down successfully refreshes and on clicking a cell it does become highlighted.
import UIKit
class ViewController: UIViewController, UITableViewDelegate
{
let blah = ["blah1"]
//How many sections are in the table?
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
//How many rows? (returns and int)
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return blah.count
}
//table contents for each cell?
//Each time this is called it'll return the next row and thus build a table...
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
print("Populating each cell of table view!\n")
tableView.rowHeight = 80.0
var cell = UITableViewCell()
var(a) = blah[indexPath.row]
var image : UIImage = UIImage(named: a)!
cell.imageView.image = image
return cell
}
//Code Cell Selected
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath){
println("You selected cell #\(indexPath.row)!")
}
func tableView(tableView: UITableViewDelegate, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
print("wananananaanan" )
println("You deselected cell #\(indexPath.row)!")
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Everybody is mentioning to set dataSource and delegate of the tableView.
But after setting also not working fine then sometimes it may happen because of none or disable selection of table view.
To enable it
Go to storyboard -> Select tableView -> click on the attribute inspector ->go to selector -> Select selection as single selection (or multiple selection according to the requirements.)
Please find attached screenshot for your suitability.
You have to set an #IBOutlet to the tableView in you ViewController and set as it's delegate and dataSource to you can see the data an respond to changes in the tableView.
Something like this :
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.delegate = self
self.tableView.dataSource = self
}
And implements the UITableViewDataSource protocol too.
Or you can too in the Interface Builder set the ViewController as it's delegate and dataSource (more easy to do I think) and avoid to set manually in code like above. Is up to you.
I hope this help you.
SWIFT 3
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
// Do here
}
Use the above delegate method in swift 3
Couple of checks that can help you:-
myTableView.allowsSelection = true
myTableView.delegate = self
Make sure you written didSelectRowAt correctly:
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
If you are using UIButton on UITableViewCell then it overlaps cell so check Solution here
I faced the same issue when compared two identical code examples where one was working well and the other was not calling didSelectRowAtIndexPath
Take a look at two possible ways to solve the issue:
1) In the code itself:
#IBOutlet weak var table: UITableView!
override func viewDidLoad() {
table.delegate = self
table.dataSource = self
//data source might be already set if you see contents of the cells
//the main trick is to set delegate
}
2) Using Storyboard or Document Outline (which was the problem in my case cause storyboard changes are not visible in .swift controller classes.
Open Document Outline and Control + Press your TableView
you will see two outlets called "delegate" and "dataSource"
drag them 1 by 1 to the containing ViewController (right onto the yellow circle)
That's it!
Another caveat is tap gesture recognizers. It's a common use case to use tap gesture recognizer to handle different logic within your view controllers with table views, whether that's exiting touch control or first responders.
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(viewTapped))
view.addGestureRecognizer(tapGesture)
E.G. This line of code handles dismissing a date picker in my application and prevents my tableview from calling didSelectRow delegate method
You have to use this: First take a look what are you extending and then use the tableView method.
class YourViewController : UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var mUITableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
// We need to tell to UITableView that we will add the data by ourselves
self.mUITableView.delegate = self
self.mUITableView.dataSource = self
// Register the UITableViewCell class with the tableView
self.mUITableView?.registerClass(UITableViewCell.self, forCellReuseIdentifier: self.cellIdentifier)
// Setup table data
getEvents()
self.mUITableView.allowsSelection = true
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return tableData.count
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
// here to create you cell view
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
print("You selected cell #\(indexPath.row)!")
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell: UITableViewCell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "subtitleCell")
cell.accessoryType = UITableViewCellAccessoryType.DisclosureIndicator
cell.textLabel?.text = "\(tableData[indexPath.row].name) - (\(tableData[indexPath.row].eventStateId))"
cell.detailTextLabel?.text = tableData[indexPath.row].lastUpdate
return cell
}
}
Another reason you may write this function which allowed to click under condition
func tableView(_ tableView: UITableView, shouldHighlightRowAt indexPath: IndexPath) -> Bool {
if(indexPath.section == 1){
return true
}
return false
}
Another caveat which took me ages to figure out is to make sure that all three of your Table View, your Cell and your Content View all have User Interaction Enabled. Then in Swift 4, at least, you can use:
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
if you are editing your tableView:
tableView.allowsSelectionDuringEditing = true
Another thing to check is the access level for your class & method:
I had a Swift UIViewController class marked #objc public, to make it visible to my objective-c code.
In this context you must add public access to this function, or it will not be called.
public func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
Nothing happened till I've cleaned and built again. :)