I have those variables in collectionviewcell file and I want to change label background and cornerradius but that file doesnt have a viewdidload how can I do that . Thanks for helps.
UIView subclasses do not have a viewDidLoad method, instead you use the view's initializer:
class MyCell: UICollectionViewCell {
override init(frame: CGRect) {
super.init(frame: frame)
layoutUI()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
layoutUI()
}
private func layoutUI() {
label.layer.cornerRadius = 5
label.backgroundColor = .blue
}
}
Related
I am trying to create a custom UILabel where the text color would be red.
Here's what I tried and none of this works:
class CustomLabel: UILabel {
override func awakeFromNib() {
UILabel.appearance().textColor = UIColor.blue
textColor = UIColor.blue
}
}
You're missing another case, a Label can be created with and without nib. Try this:
class MyCustomLabel: UILabel {
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
// This will call `awakeFromNib` in your code
setup()
}
private func setup() {
self.textColor = .red
}
}
I am writing a calendar, and each day is a cell, each cell has a Rounded UILabel in contentView, but I don't know why is there the little black border on each cell
Calendar image
In 3d View 3d preview
class CalendarCell: UICollectionViewCell {
static var identifier: String = "DayCell"
let dayLabel: UILabel = UILabel()
override init(frame: CGRect) {
super.init(frame: frame)
self.setUpUI()
self.contentView.addSubview(dayLabel)
}
private func setUpUI() {
dayLabel.text = nil
dayLabel.sizeToFit()
dayLabel.backgroundColor = .white
//dayLabel.layer.borderWidth = 0.5
dayLabel.textColor = .black
dayLabel.textAlignment = .center
dayLabel.clipsToBounds = true
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
dayLabel.frame = self.contentView.frame
dayLabel.layer.cornerRadius = dayLabel.frame.width / 2
}
override func prepareForReuse() {
super.prepareForReuse()
setUpUI()
}
I'm not sure what's causing the problem but I'm pretty sure you can fix it and achieve the same behavior by changing your code to this:
let collectionViewCellWidth: CGFLoat = 150 // or whatever you want. You'd define this in the file with your custom flow layout or wherever your give the cell size to the collectionView.
class CalendarCell: UICollectionViewCell {
static let identifier = "DayCell" // type inference doesn't need the annotations on these two
let dayLabel = UILabel()
override init(frame: CGRect) {
super.init(frame: frame)
setUpUI()
}
private func setUpUI() {
contentView.layer.cornerRadius = collectionViewCellWidth / 2
contentView.clipsToBounds = true
contentView.backgroundColor = .white // or orange, whatever
dayLabel.text = nil
dayLabel.backgroundColor = .white
//dayLabel.layer.borderWidth = 0.5
dayLabel.textColor = .black
dayLabel.textAlignment = .center
dayLabel.translatesAutoresizingMaskIntoConstraints = false
contentView.addSubview(dayLabel)
NSLayoutConstraint.activate([
dayLabel.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
dayLabel.centerYAnchor.constraint(equalTo: contentView.centerYAnchor)
])
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
//override func layoutSubviews() {
// dayLabel.frame = self.contentView.frame
// dayLabel.layer.cornerRadius = dayLabel.frame.width / 2
//}
// also as your code currently is, you don't do anything in your setup function that needs to be redone when a cell is dequeued for reuse. Unless you were setting some unique information for a cell like its color or text. Just FYI
override func prepareForReuse() {
super.prepareForReuse()
setUpUI()
}
}
How to observer in UITexFiled sub class ,if current textField is started Ending or Ended Editing in same class .
if I'll write self.delegate = self then my ViewController UITextField method will not called .
I want to make a UITexFiled SubClass when every editing is started then I'll scale up the textFiled ,and when editing is done then UITexField will be back to normal size . but I want to handle from my subclass not to write logic every UITexFeildDelegate in all ViewController Please help me .
You can add targets for the specific events
class MyTextField: UITextField {
override init(frame: CGRect) {
super.init(frame:frame)
commonInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
func commonInit() {
self.addTarget(self, action: #selector(didBegin), for: .editingDidBegin)
self.addTarget(self, action: #selector(didEnd), for: .editingDidEnd)
}
#objc func didBegin() {
}
#objc func didEnd() {
}
}
I wrote my own Button,Textfield, ..., classes. In the storyboard in "Custom Class" I set the class to the UIElement. This works very well.
Now I needed a toolbar that is added programatically. When I add the Toolbar in my ViewController everything is fine. But I want to create my own toolbar class like this.
class MyOwnToolbar : UIToolbar {
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
//never called
self.backgroundColor = UIColor.redColor()
self.tintColor = UIColor.greenColor()
self.barTintColor = UIColor.blueColor()
}
override init(frame: CGRect) {
//error: super.init isn'T called on all paths before returning from initiliazer
}
In my ViewController I try to call like this:
fromToolBar = MyOwnToolBar() //call nothing?
fromToolBar = MyOwnToolBar(frame: CGRectMake(0,0,0,0)) //doesn't work because init(frame: CGRECT) doesnt work
Old code in my ViewController that worked:
self.untilToolBar = UIToolbar(frame: CGRectMake(0,0,0,0))
untilToolBar?.backgroundColor = redColor
untilToolBar?.tintColor = greenColor
untilToolBar?.barTintColor = blueColor
So I could use my working solution, but I want to unterstand why my code isn't working. So maybe somebody have a solution or good links.
It is depending how do you create you're MyOwnToolbar if you add this in interface builder and connect class to the UI element use method initWithCoder
If you're creating your MyOwnToolbar programmatically, you should use init or initWithFrame.
Example:
class MyOwnToolbar: UIToolbar {
private func initialize() {
self.backgroundColor = UIColor.redColor()
self.tintColor = UIColor.greenColor()
self.barTintColor = UIColor.blueColor()
}
override init(frame: CGRect) {
super.init(frame: frame)
initialize()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Oleg got it right, if you use storyboard or a xib to create your view controller, then init?(coder aDecoder: NSCoder) will be called.
But you are building your view controller programmatically, so init(frame: CGRect) will be called instead of init?(coder aDecoder: NSCoder).
you should override init(frame: CGRect):
override init(frame: CGRect) {
super.init(frame: frame)
self.backgroundColor = UIColor.redColor()
self.tintColor = UIColor.greenColor()
self.barTintColor = UIColor.blueColor()
}
I have a custom UITextField and I'm trying to declare it like:
let textField = StandardTextField() // pretty much like UITextField()
My custom text field looks like:
class StandardTextField: UITextField {
init(frame: CGRect, size: CGFloat) {
super.init(frame: frame)
// some initialization
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
}
This is giving me an error because TextField has no initializer with no arguments. I tried adding:
init() {
super.init()
}
But this isn't possible since super.init() isn't the designated initializer. How can I achieve this?
You are probably looking for a convenience initialiser. But you will need to define a default frame size for your UITextField. Try like this:
class StandardTextField: UITextField {
convenience init() {
self.init(frame: CGRect(x: 0, y: 0, width: 200, height: 50))
// some initialisation for init with no arguments
}
override init(frame: CGRect) {
super.init(frame: frame)
// some initialisation for init with frame
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
}
Well unless I'm blatantly missing something, you've declared your class as class Textfield: UITextField and based on how you're trying to create your object, your class should be defined as class StandardField: UITextField and the class doesn't need any initializers as Leo said.
class StandardTextField: UITextField {
//no initializers
}