I'm trying to use a custom TableViewCell Class in my programmatically created UITableView and i can't figure out why this don't get to work. I've used custom TableViewCell Classes a few times without any problems (set the Classname in Storyboard) but here i have no Storyboard to set the Class which should be used to generate the Cells.
I'm doing this:
override func viewDidLoad() {
...
self.popupTableView.registerClass(CustomTableViewCellPopup.self, forCellReuseIdentifier: "popupTableViewCell")
...
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("popupTableViewCell") as CustomTableViewCellPopup
...
return cell
}
class CustomTableViewCellPopup: UITableViewCell {
var message: UILabel = UILabel()
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
}
required init(coder decoder: NSCoder) {
super.init(coder: decoder)
}
override func awakeFromNib() {
super.awakeFromNib()
println("I'm running!")
self.message.frame = CGRectMake(0, 0, 10, 10);
self.message.backgroundColor = UIColor.brownColor()
self.addSubview(self.message)
}
}
The println() Output never appears. The TableView gets rendered without the additional UILabel (message). Just like an out of the box UITableViewCell.
The same way (without registerClass()) i'm running a TableView with custom Cells from the Storyboard (the Classname directly defined in the Storyboard Inspector) without any problems.
Have you an idea why the custom Class don't get used?
awakeFromNib won't get called unless the cell is loaded from a xib or storyboard. Move your custom code from awakeFromNib into initWithStyle:reuseIdentifier: because that's the initializer used by the tableView when you call its dequeueReusableCellWithIdentifier: method
You're not seeing the println output because that's in awakeFromNib, which is only called if you cell comes from a storyboard or XIB. Here you're just registering the class with the table, so there's no Nib loading going on. Try making a call to configure the cell from tableView:cellForRowAtIndexPath:, rather than configuring in awakeFromNib.
initWithCoder: won't be called for the same reason - try overriding initWithStyle:reuseIdentifier:.
Related
When we are creating customView, we set the view File's owner to custom class and we instantiate it with initWithFrame or initWithCode.
When we are creating customUITableViewCell, we set the view's class to custom class, instead File's owner's. And then register all the nibs so on.
İn this way, we always need to register the xibs to UIViewController and
let cell = tableView.dequeueReusableCellWithIdentifier("reuseIdentifier", forIndexPath: indexPath)so on.
What I find is that I don't want to register nibs all the time where I want to use customUITableViewCell. So I want to initialize xib inside my customUITableCell like the same process of creating customUIView. And I succeed. Here are the steps.
My question is what is the preferred way of creating customUITableCell?
With this method there is no need to register nibs and we can call customCell where we want to without loading/registering nib.
Set the view's File's Owner of xib to customUITableCell class. Not the view's class set to customClass, just File's Owner.
Image 1
My custom class called myView: UITableViewCell
import UIKit
class myView: UITableViewCell {
var subView: UIView!
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
initSubviews()
}
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
initSubviews()
}
func initSubviews(){
subView = Bundle.main.loadNibNamed("TableViewCell", owner: self, options: nil)?.first as! UIView
subView.autoresizingMask = UIViewAutoresizing(rawValue: UIViewAutoresizing.RawValue(UInt8(UIViewAutoresizing.flexibleWidth.rawValue) | UInt8(UIViewAutoresizing.flexibleHeight.rawValue)))
self.addSubview(subView)
}
}
İnside UIVivController, I did't register nibs and use
let cell = tableView.dequeueReusableCellWithIdentifier("reuseIdentifier", forIndexPath: indexPath)
Instead, I did this.
let cell = myView(style: .default , reuseIdentifier: "TableViewCell")
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var tableStyle: UITableView = UITableView()
override func viewDidLoad() {
super.viewDidLoad()
tableStyle.frame = CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height)
tableStyle.delegate = self
tableStyle.dataSource = self
view.addSubview(tableStyle)
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100.00
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1 }
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = myView(style: .default , reuseIdentifier: "TableViewCell")
return cell
}
}
Here is the result.
Image 4
THANKS FOR YOUR TIME!!!
Your approach means every single time the UITableView requests a new cell, you're creating a brand new cell from scratch. That it means it has to:
find the nib
load the nib
parse it to find the views
make the views
update the cell
This is no better than having a long scroll view with custom views for it's entire length.
The beauty of UITableView is it optimizes much of this process and re-uses cells, massively cutting down the performance cost of having more cells than fit on your screen. With the traditional (correct) approach, steps 1-4 only have to happen once.
To expand on the differences in the xib:
When creating a cell with UITableView, you only give it the nib, and the system looks in the nib to find a UITableViewCell. A simple UIView will not work.
You actually can subclass the UIView in your xib with your custom class. It just happens that the norm is to use fileOwner, largely because that's the norm when using nibs with UIViewControllers as was required in the pre-storyboard era
An addition to the accepted answer:
If your only problem with the "classic" approach is that you need to register the nib and call dequeueReusableCell, you can simplify the calls with a nice protocol extension as discussed in this article:
protocol ReuseIdentifying {
static var reuseIdentifier: String { get }
}
extension ReuseIdentifying {
static var reuseIdentifier: String {
return String(describing: Self.self)
}
}
extension UITableViewCell: ReuseIdentifying {}
To register you just call
self.tableView.register(UINib(nibName: MyTableViewCell.reuseIdentifier, bundle: nil), forCellReuseIdentifier: MyTableViewCell. reuseIdentifier)
And to create it you call
let cell = self.tableView.dequeueReusableCell(withIdentifier: MyTableViewCell. reuseIdentifier, for: indexPath) as! MyTableViewCell
(Of course this only works if class, xib and reuse identifier all have the same name)
I'm creating a settings page for my Swift app and (following examples here on SO) I've subclassed a UITableViewCell and in the init() handlers I've set the accessoryView to be a UISwitch().
I also have a custom #IBInspectable property on the subclass which is also marked #IBDesignable:
#IBDesignable class TableViewSwitchCell: UITableViewCell {
#IBInspectable var settingsKey: String?
func build()
{
accessoryView = UISwitch()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
build()
}
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
build()
}
// code omitted that uses the settingsKey with NSUserDefaults
}
How can I arrange for the UISwitch to also be visible in InterfaceBuilder so that I can attach additional targets to it whilst still just subclassing from UITableViewCell
Ideally I don't want to create a whole new nib with its own layout, since I still want to retain most of the other features of a standard UITableViewCell.
Drop UISwitch in Interface Builder inside of cell. Then wire it with up accessoryView of your cell. On standard basic cells the control tends to be locked in the middle of cell in IB. However in runtime it will be properly positioned.
I have a custom UITableViewCell subclass with a simple IBOutlet setup for a UILabel.
class SegmentCell: UITableViewCell {
#IBOutlet weak var test: UILabel!
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
test.text = "Some Text"
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Convinced I have everything set up correct have followed other answers, but the UILabel is always nil.
ViewController:
viewDidLoad:
self.tableView.registerClass(SegmentCell.self, forCellReuseIdentifier: "Cell")
cellForForAtIndexPath
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell") as! SegmentCell
return cell
}
Cell is set to Custom
Reuse identifier is correct
Cells class is SegmentCell
Tableview content is Dynamic Prototypes
What am I missing?
Since You are uisg Xib file you have to register with ,
tableView.register(UINib(nibName: "yourNib", bundle: nil), forCellReuseIdentifier: "CellFromNib")
Think, if only register with class ,system will not know the its Xib.This work for me.
Based on the way you register your cell, it is not going to be loading it from a storyboard or xib file. It will be invoking that init method only. Your init method does not create the label, so it will always be nil.
You should also use dequeueReusableCellWithIdentifier(_:forIndexPath:) instead of dequeueReusableCellWithIdentifier(_:). The latter predates storyboards and will return nil unless you have previously created a cell with that identifier and returned it.
Lastly, the init method that the tableView is calling is not the one you've implemented, or the app would crash on test.text = ... while trying to unwrap a nil optional.
UITableViewCell class and ContentView class can't be same.
You should register it first in the viewDidLoad function.
self.tableView.registerClass(CustomCell.self, forCellReuseIdentifier: "Cell")
I have same issue, after add custom cell class to cell in tableview placed in Storyboard.
I also register cell, like in documentation. But now I solve my issue.
"I remove registering and inspect cell again, all IBOutlets initialised"
I think that basically the outlets are not setup yet at init time. If you want to get to the outlets and manipulate them, then override didMoveToSuperview or similar and do it in there. For instance, this is what I had to do to get to the button outlet in my cell:
open class MyTableViewCell: UITableViewCell {
// Top stack view, not the inner one.
#IBOutlet weak var stackView: UIStackView!
#IBOutlet weak var buttonView: UIButton?
open override func didMoveToSuperview() {
buttonView?.titleLabel?.adjustsFontForContentSizeCategory = true
}
func adjustForAccessibilityCategory(accessible: Bool) {
if accessible {
stackView.axis = .vertical
stackView.alignment = .leading
stackView.spacing = 2
} else {
stackView.axis = .horizontal
stackView.alignment = .center
stackView.spacing = 20
}
}
open override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
if #available(iOS 11.0, *) {
adjustForAccessibilityCategory(accessible: traitCollection.preferredContentSizeCategory.isAccessibilityCategory)
}
}
}
I'm creating a productivity app in Swift. I'm not using a prototype cell in the Storyboard as most of it has been written in code already. I'd like to a checkbox button.
How would I go about doing that?
While the answer from Tim is technically correct, I would not advise on doing this. Because the UITableView uses a dequeuing mechanism, you could actually receive a reused cell which already has a button on it (because you added it earlier). So your code is actually adding a 2nd button to it (and a 3rd, 4th, etc).
What you want to do, is create a subclass from the UITableViewCell which adds a button to itself, while it is being instantiated. Then you can just dequeue that cell from your UITableView and it will automatically have your button on it, without the need to do it in the cellForRowAtIndexPath method.
Something like this:
class MyCustomCellWithButton: UITableViewCell {
var clickButton = UIButton.buttonWithType(UIButtonType.Custom) as! UIButton;
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier);
self.contentView.addSubview(self.clickButton);
}
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
And then you can actually dequeue it in the cellForRowAtIndexPath like this.
var cell = tableView.dequeueReusableCellWithIdentifier("my-cell-identifier") as? MyCustomCellWithButton;
if (cell == nil) {
cell = MyCustomCellWithButton(style: UITableViewCellStyle.Default, reuseIdentifier: "my-cell-identifier");
}
return cell!;
Well, first of all your cellForRowAtIndexPath should probably use the dequeue mechanism so you aren't recreating cells every time when virtualizing.
But that aside, all you need to do is create the button, and add it as a sub view to the cell.
cell.addSubview(newButton)
But of course then you will have to manage the sizing and layout as appropriate.
A UITableViewCell also has a selected state and a didSelect and didDeselect method available that listens to taps on the whole cell. Perhaps that's a bit more practical since you seem to want to check/uncheck checkboxes, which is more or less the same as selecting. You could set the cell in selected state right after you dequeued it.
I am trying to create a custom cell for my UITableView but I am having some difficulty.
First off I cannot use the Interface Builder, as I am experiencing a variation on this bug in Xcode. Every time I click on an element in the Interface Builder everything in that view gets a height and width of zero and gets repositioned outside of the view. Besides, I would like to learn how to do this programmatically.
Secondly I am using the Swift language for my project. I have been trying to follow this demonstration, and doing my best to convert the Objective C code over to Swift, but whenever I run into problems I end up being stuck. I presume this is because I am not converting the code over correctly.
Thirdly I found this video but despite being fairly difficult to follow (lots of the code is just copied and pasted without much explanation to what it does or why), it still ends up using the Interface Builder to change various parts.
I have a basic UITableView set up fine. I just want to be able to add a custom cell to that table view.
Can this be done using pure programming, or do I need to use the Interface Builder?
Can anyone point me in the right direction or help me out in creating a custom cell programmatically in Swift?
Many thanks.
In general: Everything is possible in pure programming ;-)
Create a custom class for your tableView cell and there setup all the elements, properties and the visual layout. Implement the required methods init(style,reuseidentifier)
In your custom class for the UITableViewController register the custom cell class using registerClass(forCellReuseIdentifier)
Setup your delegate and datasource for the custom tableViewController
Finally, you create the cells in cellForRowAtIndexPath:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("myReuseIdentifier", forIndexPath: indexPath) as MyCustomTableViewCell
// configure the cell using its properties
return cell
}
This should be the basic steps.
If you're looking for more code, here is an example of a custom cell that I created:
// File: vDataEntryCell.swift
import UIKit
class vDataEntryCell: UITableViewCell
{
//-----------------
// MARK: PROPERTIES
//-----------------
//Locals
var textField : UITextField = UITextField()
//-----------------
// MARK: VIEW FUNCTIONS
//-----------------
///------------
//Method: Init with Style
//Purpose:
//Notes: This will NOT get called unless you call "registerClass, forCellReuseIdentifier" on your tableview
///------------
override init(style: UITableViewCellStyle, reuseIdentifier: String!)
{
//First Call Super
super.init(style: style, reuseIdentifier: reuseIdentifier)
//Initialize Text Field
self.textField = UITextField(frame: CGRect(x: 119.00, y: 9, width: 216.00, height: 31.00));
//Add TextField to SubView
self.addSubview(self.textField)
}
///------------
//Method: Init with Coder
//Purpose:
//Notes: This function is apparently required; gets called by default if you don't call "registerClass, forCellReuseIdentifier" on your tableview
///------------
required init(coder aDecoder: NSCoder)
{
//Just Call Super
super.init(coder: aDecoder)
}
}
Then in my UITableViewController class I did the following:
// File: vcESDEnterCityState.swift
import UIKit
class vcESDEnterCityState: UITableViewController
{
//-----------------
// MARK: VC FUNCTIONS
//-----------------
///------------
//Method: View Will Appear
//Purpose:
//Notes:
///------------
override func viewWillAppear(animated: Bool)
{
//First Call Super
super.viewWillAppear(animated)
//Register the Custom DataCell
tvCityStateForm.registerClass(vDataEntryCell.classForCoder(), forCellReuseIdentifier: "cell")
}
//-----------------
// MARK: UITABLEVIEW DELEGATES
//-----------------
///------------
//Method: Cell for Row at Index Path of TableView
//Purpose:
//Notes:
///------------
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
//Get Reference to Cell
var cell : vDataEntryCell = self.tableView.dequeueReusableCellWithIdentifier("cell") as vDataEntryCell
//...Do Stuff
//Return Cell
return cell
}
}