I read here that you have to use pickerView.selectRow inside viewDidAppear(). While pickerView.selectRow is working inside func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) it does not work in viewDidAppear().
I just want to set the initial row to another row than 0
What am I missing here?
import UIKit
class FirstViewController: UIViewController, UIPickerViewDelegate {
let scrollerOfset = 100
var kiloMeters = [Int](-100...200)
#IBOutlet weak var pickerActive: UILabel!
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.
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
pickerView.selectRow(scrollerOfset, inComponent: 0, animated: false)
}
}
Xcode gives this error
Cannot invoke 'selectRow' with an argument list of type '(Int, inComponent: Int, animated: Bool)'
at line 32 (in viewDidAppear(animated: Bool))
Update
Code changed to this to make it work:
import UIKit
class FirstViewController: UIViewController, UIPickerViewDelegate {
let scrollerOfset = 100
var kiloMeters = [Int](-100...200)
#IBOutlet weak var pickerActive: UILabel!
#IBOutlet weak var picker: UIPickerView!
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.
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
picker.selectRow(scrollerOfset, inComponent: 0, animated: false)
}
}
Seems you are missing the declaration of pickerView property in your class, try declare it with under pickerActive, like
#IBOutlet weak var pickerActive: UILabel!
#IBOutlet weak var picker: UIPickerView!
Then connect it thru IB like pickerActive
Related
I am trying to handle the keyboard notifications using a separate class.
Class-KeyboardHandling:
class KeyboardHandling{
class func addObserverKeyboardWillShow(){
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: .UIKeyboardWillShow, object: nil)
}
#objc func keyboardWillShow(notification: NSNotification){
let duration = notification.userInfo![UIKeyboardAnimationDurationUserInfoKey] as! Double
print(duration)
}
}
MainVC:
class MainVC: UIViewController {
//MARK: Outlets
#IBOutlet weak var textInput: UITextField!
#IBOutlet weak var bottomToolbar: UIToolbar!
#IBOutlet weak var toolbarBottonConstraint: NSLayoutConstraint!
//MARK: Variables
var toolBarIntialBottomConstraint: CGFloat!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func viewDidAppear(_ animated: Bool) {
toolBarIntialBottomConstraint = toolbarBottonConstraint.constant
KeyboardHandling.addObserverKeyboardWillShow()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
The implementation works perfectly when addObserverKeyboardWillShow() is not a class function.
I get the error otherwise
Error Screenshot (Xcode 8.0):
Can someone explain why the same?
I am trying to print out the text of a UITextField to the console when a button is tapped. However, I am getting an error that says it cannot unwrap a nil. By default, I have a value typed into in and when I insert a new value, both produce this error. These IBOutlets are appropriately linked.
#IBOutlet weak var entranceFeeTextField: UITextField!
#IBAction func saveButtonTapped(sender: UIButton) {
print("The entrance fee is \(entranceFeeTextField.text)")
}
My class is only conforming to UITableViewCell and UITextFieldDelegate, and not to UIViewController. Could that be the error?
Do something like this
if let text = self.entranceFeeTextField.text {
print(text)
}
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var theTextField: UITextField!
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.
}
#IBAction func onButtonPressed(sender: UIButton) {
print(self.theTextField.text)
}
}
http://i.stack.imgur.com/NXYaK.png
It Should Be Like
#IBOutlet weak var test: UITextField!
#IBAction func btn(sender: AnyObject) {
let txt = test.text!
print(txt)
}
Hope It Helps.
I can't assign the variable of an Int to the UILabel, how can I fix this?
import UIKit
class ViewController: UIViewController {
#IBOutlet var CoinCounterInt: UILabel!
#IBOutlet weak var CoinCounter: UILabel!
var coins = 0
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.
}
#IBAction func Clicker(sender: AnyObject) {
coins += 1
CoinCounterInt = "\(coins)"
}
}
You need to assign the the string to the text property of the label:
CoinCounterInt.text = "\(coins)"
I am trying to setup a popover view containing a textfield and a tableview, but I couldn't make the tableview to show the data. It would be much appreciated if you could help me on this.
On the main ViewController, I put a label to trigger the segue of popover,
import UIKit
class ViewController: UIViewController, UIPopoverPresentationControllerDelegate {
#IBOutlet weak var textField: UITextField!
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.
}
#IBAction func popover(sender: AnyObject) {
self.performSegueWithIdentifier("ShowDetails", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "ShowDetails" {
if let controller = segue.destinationViewController as? UIViewController {
controller.popoverPresentationController!.delegate = self
controller.preferredContentSize = CGSize(width: 320, height: 50)
}
}
}
func adaptivePresentationStyleForPresentationController(controller: UIPresentationController) -> UIModalPresentationStyle {
return .None
}
}
A PopoverCell is setup for the prototype cell,
import UIKit
class PopoverCellTableViewCell: UITableViewCell {
#IBOutlet weak var AreaCellLabel: UILabel!
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
}
}
A PopoverControllerView is set for the popover itself.
import UIKit
class PopoverViewController: UIViewController, UITextFieldDelegate, UITableViewDataSource, UITableViewDelegate {
var areas = [Area]()
// #IBOutlet weak var NewArea: UITextField!
// #IBOutlet weak var SaveNewArea: UIButton!
#IBOutlet weak var subtableView: UITableView!
override func viewDidLoad() {
subtableView.dataSource = self
subtableView.delegate = self
super.viewDidLoad()
LoadsampleArea()
// Do any additional setup after loading the view.
}
func LoadsampleArea () {
let area1 = Area(AreaName:"Moountain")!
let area2 = Area(AreaName:"ByHill")!
let area3 = Area(AreaName:"Yard")!
areas += [area1, area2, area3]
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return areas.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
// Table view cells are reused and should be dequeued using a cell identifier.
let cellIdentifier = "AreaCell"
let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! PopoverCellTableViewCell
let area = areas[indexPath.row]
cell.AreaCellLabel.text = area.AreaName
dismissViewControllerAnimated(true, completion:nil)
return cell
}
}
and a simple data file to put the data.
import UIKit
class Area {
var AreaName: String
init? (AreaName: String) {
self.AreaName = AreaName
if AreaName.isEmpty {
return nil
}
}
}
Where is your UITableView object in your PopoverViewController class ? I can't see any reference to it.
Maybe your didn't copy-paste it since the textfield is commented too, in this case I'll suggest to check if the delegate an datasource are set property.
import UIKit
var typingSpace = 80
class ViewController: UIViewController {
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.
}
#IBOutlet weak var typingSpace: UIView!
#IBOutlet weak var displayLabel: UILabel!
}
Basically what I'm doing is this: when I type a certain number (let's say 70) in a text box, the label will display something (eg. Your number is 70). I honestly have no idea what I'm doing. Please help.
You need 4 things
Add a outlet for your text view so you'll have #IBOutlet weak var textView: UITExtView!
Make ViewController implement UITextViewDelegate
ViewController: UIViewController, UITextViewDelegate
Make self delegate of textView on viewDidLoad:
textView.delegate = self
Implement textViewDidChange and put your logic in there
func textViewDidChange(textView: UITextView) {
// change your label text
}
Here you have be a complete class example
class ViewController: UIViewController, UITextViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.textView.delegate = self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func textViewDidChange(textView: UITextView) {
displayLabel.text = "your text"
}
#IBOutlet weak var textView: UITextView!
#IBOutlet weak var typingSpace: UIView!
#IBOutlet weak var displayLabel: UILabel!
}
Note: #Claudio Redi has supplied the correct answer, this is another way to populate a label from a UITextField.
This is one way of accomplishing your task:
class ViewController: UIViewController {
#IBOutlet weak var typingSpace: UITextField!
#IBOutlet weak var displayLabel: UILabel!
#IBAction func handleButtonPressed(sender: UIButton) {
displayLabel.text = typingSpace.text
}
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.
}
}