how do I load the UIpicker on page load in swift? - ios

I have two pickers and I want picker1 to be show by default when the page first loads and also when user touches the UI. I want to show in both ways for picker1.
func numberOfComponents(in pickerView: UIPickerView) -> Int {
if pickerView == picker1 {
return 1
} else {
return 2
}
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
var tempCount = 0
if pickerView == picker1 {
tempCount = pickerData.count
} else {
}
return tempCount
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
var tempPickerData = ""
if pickerView == picker1 {
tempPickerData = pickerData[row]
} else {
}
return tempPickerData
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if pickerView == picker1 {
selected = pickerData[row]
} else {
}
}

Related

for loop in titleForRow in pickerView not working

I was creating a clock pickerView and used the following:
var countSec = Array(0...10)
var countMin = Array(0...59)
var countHour = Array(0...59)
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if component == 0{
for count in countSec {
return "\(count)"
}
}else{
for count in countMin{
return "\(count)"
}
}
return nil
}
But when I run, all the data was 0s.
Don't use loops in titleForRow. Just return the appropriate value for the requested row.
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if component == 0 {
return "\(countSec[row])"
} else {
return "\(countMin[row])"
}
}

Content in PickerView not showing up

I am new with programming in Swift. i got problem when i want to show up 2 different picker with 2 different content. But it show (?) instead of content.
see the screenshoot below
Thank your for help!
let fruit = ["apple", "orange", "watermelon", "banana", "peach", "strawberry"]
let food = ["rice","bread","spagheti","milk"]
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if (pickerView.tag == 1) {
return fruit.count
}
else {
return food.count
}
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if (pickerView.tag == 1) {
return fruit[row]
}
else {
return food[row]
}
}
First of all check you pickerView DataSource and Delegate connected properly and then you can conditionally load data by comparing pickerView like below.
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if pickerView == YOUR_FIRST_PICKER {
return fruit.count
}
else {
return food.count
}
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if pickerView == YOUR_FIRST_PICKER {
return fruit[row]
}
else {
return food[row]
}
}
I think you haven’t set your pickers’ delegates and data sources.
First add these protocols to your ViewController subclass
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource
then in viewDidLoad set delegates and data sources of your pickers as self
override func viewDidLoad() {
super.viewDidLoad()
pickerView1.delegate = self
pickerView1.dataSource = self
pickerView2.delegate = self
pickerView2.dataSource = self
}

Having multiple Picker Views

I am trying to have multiple picker views in one single view in swift.
So far I have created 2 different textfields and I want both of them to have different picker views if I click on them. so let us say if click on textfield #1 it opens the array #1 and textfields #2 the second.
I have already looked up these questions but they do not really answer my question or solve my problem:
Multiple Picker Views on a single view
Creating Multiple Dynamic Picker Views
so my View Controller looks like this:
how my viewController should look
and this is my piece of code:
let pickOption = ["kg","lb"] //first array for first textfield
let ageOption = ["0-5", "6-10", "11-15"] //array for 2nd textfield
let pickerView = UIPickerView()
//picker View functions
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return pickOption.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return pickOption[row]
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
weightTextField.text = pickOption[row]
}
override func viewDidLoad() {
super.viewDidLoad()
pickerView.delegate = self
pickerView.dataSource = self
weightTextField.inputView = pickerView
weightTextField.text = pickOption[0]
}
so as mentioned before, the first textfield opens up the array 'pickOption' and the second array opens up 'ageOption'
EDIT: 'weightTextField' ist the first textfield which opens up the first array(pickOption)
We can do it for multiple UITextField from single PickerView, with the help of UITextFieldDelegate
let pickOption = ["kg","lb"] //first array for first textfield
let ageOption = ["0-5", "6-10", "11-15"] //array for 2nd textfield
let pickerView = UIPickerView()
var currentTxtFldTag : Int = 10
override func viewDidLoad() {
super.viewDidLoad()
pickerView.delegate = self
pickerView.dataSource = self
weightTextField.tag = 10
ageTextField.tag = 20
weightTextField.delegate = self
ageTextField.delegate = self
weightTextField.inputView = pickerView
weightTextField.text = pickOption[0]
ageTextField.inputView = pickerView
ageTextField.text = ageOption[0]
// Do any additional setup after loading the view.
}
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if currentTxtFldTag == 10
{
return pickOption.count
}
else
{
return ageOption.count
}
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if currentTxtFldTag == 10
{
return pickOption[row]
}
else
{
return ageOption[row]
}
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if currentTxtFldTag == 10
{
weightTextField.text = pickOption[row]
}
else
{
ageTextField.text = ageOption[row]
}
}
func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
if textField.tag == 10 // WEIGHT OPTION
{
currentTxtFldTag = 10
}
else // AGE OPTION
{
currentTxtFldTag = 20
}
pickerView.reloadAllComponents()
return true
}
Output
Suppose that you have two pickerView controls: picker0 and picker1.
class HomeViewController: BasicViewController, UITextFieldDelegate, UITextViewDelegate, UIPickerViewDelegate, UIPickerViewDataSource {
let numberArray = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180]
var areaArray = [String]()
#IBOutlet weak var picker0: UIPickerView!
#IBOutlet weak var picker1: UIPickerView!
override func viewDidLoad() {
super.viewDidLoad()
// area //
for i in 0..<11 {
let str = "Area "
let localStr = NSLocalizedString(str + String(i), comment: "")
areaArray.append(localStr)
}
}
// MARK: - Campaign duration & area
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if pickerView == picker0 {
return numberArray.count
} else {
return areaArray.count
}
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if pickerView == picker0 {
return String(numberArray[row]) + " pieces"
} else {
return areaArray[row]
}
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if pickerView == seventhPicker {
} else {
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
pickerView.delegate = self
pickerView.dataSource = self
weightTextField.inputView = pickerView
}
let pickOption = ["kg","lb"] //first array for first textfield
let ageOption = ["0-5", "6-10", "11-15"] //array for 2nd textfield
let pickerView = UIPickerView()
//picker View functions
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if weightTextField1.tag == 1 {
return pickOption.count
} else if weightTextField2.tag == itemPicker {
return ageOption.count
}
return 0
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if weightTextField1.tag == 1 {
return pickOption[row]
} else if weightTextField2.tag == 1 {
return ageOption[row]
}
return 0
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if weightTextField1.tag == 1 {
weightTextField1.text = pickOption[row]
} else if weightTextField2.tag == 1 {
weightTextField2.text = ageOption[row]
}
}
////set delegate
func textFieldDidBeginEditing(textField: UITextField!) { //delegate method
if textField == weightTextField1
{
weightTextField1.atg = 1;
weightTextField2.atg = 0;
}
else if textField == weightTextField2
{
weightTextField1.atg = 0;
weightTextField2.atg = 1;
}
picker.reloadAllComponents()
}
}

UIPickerView depending on first component

So I have a UIPickerView with two components. The first one called "Cupboards", the second "Drawer". They have a one to many relationships in CoreData Cupboards <-->> Drawer. I would like that if I select a Cupboard, only the matching Drawers get displayed. I'm not sure how to get that working with the relationship.
That's what I have for showing the Cupboard:
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 2
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if(component==0){
return cupboards.count
}
xxxx
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if(component==0){
return cupboards[row].name
}
xxxx
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if(component==0){
}
}
Thank you in advance
Update:
Got it like that now, but I get no results.
var cupboardDrawers = [Drawer]()
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if(component==0){
let request: NSFetchRequest<Drawer> = Drawer.fetchRequest()
request.predicate = NSPredicate(format: "cupboard == %#", cupboards[row].name!)
do{
let result = try mgdContext.fetch(request)
cupboardDrawers = result
addEatDataPicker.reloadAllComponents()
}catch{
print(error.localizedDescription)
}
}
}
You need to create and update a cupboardDrawers array with the fetching results:
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 2
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if(component==0){
return cupboards.count
} else {
return cupboardDrawers.count
}
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if(component==0){
return cupboards[row].name
} else {
return cupboardDrawers[row].yourProperty
}
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if(component==0){
// you can add this part to a separate function and call it here
cupboardDrawers = []
let request = NSFetchRequest<Drawer>(entityName:”Drawer”)
request.predicate = YourPredicate with cupboards[row].name
do {
let items = context.fetch(request)
guard items.count > 0 else {
print(“no items found”)
return
}
cupboardDrawers = items
//reload your picker
} catch {
print(error)
}
}
}

Using Two UI Pickers in 1 VC, Handling Delegate methods

I have 2 pickers in 1 VC and know that this should be handled by using if else to identify which delegate methods each should follow. However Im new to getting my head around this and im not sure what i should be returning on my methods in order to have them work correctly.
Here is the code, I have just used 0 and "" to prevent code errors for now until I can get the correct returns sorted out.
func numberOfComponents(in pickerView: UIPickerView) -> Int {
if pickerView == repsPicker {
return 1
} else if pickerView == setsPicker {
return 1
}
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if pickerView == repsPicker {
return repPickerValues.count
} else if pickerView == setsPicker {
return self.setsPickerValues.count
}
return 0
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if pickerView == repsPicker {
return repPickerValues[row]
} else if pickerView == setsPicker {
return self.setsPickerValues[row]
}
return ""
}
You can set tag to each picker so that you can differentiate between them. Set pickerView.tag with two different values, and in each delegate method check the tag value to determine the return value.
let repPickerValues = ["America", "Mexico", "Canada"]
let setsPickerValues = ["India", "China", "Malaysia", "Singapore"]
If these are your values, then you will have 3 options on 1st picker and 4 options on 2nd picker.
Adding below lines will call those functions
repsPicker.delegate = self
setsPicker.delegate = self
And your view controller class should conform to UIPickerViewDelegate and UIPickerViewDataSource. Like
class ViewController: UIPickerViewDelegate, UIPickerViewDatSource {
}
This function will tell picker view how many options are to be shown
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if pickerView == repsPicker {
return repPickerValues.count
} else if pickerView == setsPicker {
return self.setsPickerValues.count
}
return 0
}
This function is responsible for placing values in picker view
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if pickerView == repsPicker {
return repPickerValues[row]
} else if pickerView == setsPicker {
return self.setsPickerValues[row]
}
return ""
}
Is this what you are asking for?
I can see several options here :
Use different delegate objects for each picker
picker1.delegate = firstDelegate()
picker2.delegate = secondDelegate()
Implement the desired delegate methods differently in each of the delegate objects.
Keep a reference to each picker in your view controller (or IBOutlet)
let picker1 = ...
let picker2 = ...
Then in your delegate method(s)
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if pickerView == picker1 {
...
}
}

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