I have problem with a picker view that appears empty when I make it in second view controller.(image1).
When I make it in the first view controller that work fine.
two view controller and pickerview
code:
import UIKit
class ViewController: UIViewController, UIPickerViewDelegate {
var civilite = ["Madame","Monsieur","Mademoiselle"]
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return civilite.count
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String!{
return civilite[row]
}
}
Xcode 6.4
I found the solution.
I add new file "Cocoa touch class" (Formulaire.swift) I change the custom class of the second view controller to be "Formulaire" [Custom class][1]
[1]: http://i.stack.imgur.com/H4Nip.png
I deplace the code in this file and is work fine.
Thanks
Related
I have encountered some synchronisation/graphic update problems with my UIPickerView.
I want a view with 2 components, where the content of the second component depends on the selected row of the first component.
My code is inspired from: Swift UIPickerView 1st component changes 2nd components data
However, while it seems to work, sometimes (not every time) there are some visual problems, as seen on the screenshots below. (on the second screenshot, you can see that the rows of the second component are not really correct, and are a mix of the rows from the first and the second component)
Here is the code:
import UIKit
class AddActivityViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
#IBOutlet weak var typePicker: UIPickerView!
var pickerData: [(String,[String])] = []
override func viewDidLoad() {
super.viewDidLoad()
self.typePicker.delegate = self
self.typePicker.dataSource = self
pickerData = [("sport",["bike", "run", "soccer", "basketball"]),
("games",["videogame", "boardgame", "adventuregame"])]
// not sure if necessary
typePicker.reloadAllComponents()
typePicker.selectRow(0, inComponent: 0, animated: false)
// pickerData = [("sport",["bike", "run", "soccer"]),
// ("games",["videogame", "boardgame", "adventuregame"])]
}
// number of columns in Picker
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 2
}
// number of rows per column in Picker
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
print("function 1 called")
if component == 0 {
return pickerData.count
} else {
let selectedRowInFirstComponent = pickerView.selectedRow(inComponent: 0)
return pickerData[selectedRowInFirstComponent].1.count
}
}
// what to show for a specific row (row) and column (component)
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
print("function 2 called with values: component: \(component), row: \(row)")
if component == 0 {
// refresh and reset 2nd component everytime another 1st component is chosen
pickerView.reloadComponent(1)
pickerView.selectRow(0, inComponent: 1, animated: true)
// return the first value of the tuple (so the category name) at index row
return pickerData[row].0
} else {
// component is 1, so we look which row is selected in the first component
let selectedRowInFirstComponent = pickerView.selectedRow(inComponent: 0)
// we check if the selected row is the minimum of the given row index and the amount of elements in a given category tuple array
print("---",row, (pickerData[selectedRowInFirstComponent].1.count)-1)
let safeRowIndex = min(row, (pickerData[selectedRowInFirstComponent].1.count)-1)
return pickerData[selectedRowInFirstComponent].1[safeRowIndex]
}
//return pickerData[component].1[row]
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
// This method is triggered whenever the user makes a change to the picker selection.
// The parameter named row and component represents what was selected.
}
}
Is this a problem with my code or generally a complicated aspect of UIPickers that can not be trivially solved?
Additionally, is there a nicer way to develop this functionality?
I solved the error, however I do not understand why this solves it.
The solution is to imlement the func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)method, which I did not believe to be necessary just to show the fields.
In other words, just add this to my existing code:
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if component == 0 {
pickerView.reloadComponent(1)
} else {
let selectedRowInFirstComponent = pickerView.selectedRow(inComponent: 0)
print(pickerData[selectedRowInFirstComponent].1[row])
}
}
I don't know what I've done to anger the gods but my UIPickerView is behaving abnormally. It has 2 components, for month and year values, and selecting a value on the right component (year) causes the left component (month) to change value as well.
I initially create the UIPickerView using the following code:
pickerView = UIPickerView(frame: ...)
pickerView.delegate = self
pickerView.dataSource = self
Then I implement some simple delegate / data source methods to handle the picker view, as follows:
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if component == 0 {
expirationMonth = months[row]
} else {
expirationYear = years[row]
}
expirationTextField?.text = "\(expirationMonth ?? "")/\(expirationYear?.substring(from: 2) ?? "")"
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if component == 0 {
return months[row]
} else {
return years[row]
}
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if component == 0 {
return months.count
} else {
return years.count
}
}
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 2
}
Additionally, the UIPickerView data source method numberOfComponents is being called even when I don't set the picker view's data source.
I have no idea what's causing this behavior. I've tried pretty much everything and nothing is stopping it from changing both column's values. Does anyone have any ideas to fix this?
Turns out it's a bug in the iOS simulator, because when running it on my iPhone it worked like a charm. I thought I was going crazy there for a second!
I'm going to file a bug complaint in the morning...Good luck to anyone else with this issue.
I keep getting an "'-[UITableView numberOfComponentsInPickerView:]: unrecognized selector sent to instance" error referencing a method in one of my custom UITableViewCell classes, and I can't seem to figure out why. I've searched through stack overflow but can't find an answer related to my situation. Any ideas? Thanks!
public class PickerTableViewCell:UITableViewCell, UIPickerViewDataSource, UIPickerViewDelegate {
var pickerData:[Array<Int>] = []
#IBOutlet weak var picker: UIPickerView!
public func configure(data:[Array<Int>]) {
pickerData = data
}
// Picker functions
public func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return pickerData.count
}
public func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return pickerData[component].count
}
public func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
return String(pickerData[component][row])
}
}
If you look at the error message you see that the method numberOfComponentsInPickerView: was invoked on a UITableView instance.
So you ask the question "why would that method be invoked on a UITableView?"
The method in question is a picker view data source method, so that means that somewhere you assigned a UITableView as a picker view's data source, so that when the picker view was displayed the method call was made against a class (UITableView) that hadn't implemented the delegate method.
In your case it was a simple drag-drop error in Interface Builder.
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What is the library to make drop down menu in swift? I am new to Xcode and the Swift language, so can anyone please direct me on how to implement the drop down list in swift?
(Swift 3) Add text box and uipickerview to the storyboard then add delegate and data source to uipickerview and add delegate to textbox. Follow video for assistance
https://youtu.be/SfjZwgxlwcc
import UIKit
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource, UITextFieldDelegate {
#IBOutlet weak var textBox: UITextField!
#IBOutlet weak var dropDown: UIPickerView!
var list = ["1", "2", "3"]
public func numberOfComponents(in pickerView: UIPickerView) -> Int{
return 1
}
public func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int{
return list.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
self.view.endEditing(true)
return list[row]
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
self.textBox.text = self.list[row]
self.dropDown.isHidden = true
}
func textFieldDidBeginEditing(_ textField: UITextField) {
if textField == self.textBox {
self.dropDown.isHidden = false
//if you don't want the users to se the keyboard type:
textField.endEditing(true)
}
}
}
A 'drop down menu' is a web control / term. In iOS we don't have these. You might be better looking at UIPopoverController. Check out this tutorial for a bit of an insight to PopoverControllers
http://www.raywenderlich.com/29472/ipad-for-iphone-developers-101-in-ios-6-uipopovercontroller-tutorial
Unfortunately if you're looking to apply UIPopoverController in iOS9, you'll get a deprecated class warning. Instead you need to set your desired view's UIModalPresentationPopover property to achieve the same result.
Popover
In a horizontally regular environment, a presentation style
where the content is displayed in a popover view. The background
content is dimmed and taps outside the popover cause the popover to be
dismissed. If you do not want taps to dismiss the popover, you can
assign one or more views to the passthroughViews property of the
associated UIPopoverPresentationController object, which you can get
from the popoverPresentationController property.
In a horizontally compact environment, this option behaves the same as
UIModalPresentationFullScreen.
Available in iOS 8.0 and later.
Reference: https://developer.apple.com/documentation/uikit/uiviewcontroller/1621355-modalpresentationstyle
You have to be sure to use UIPickerViewDataSource and UIPickerViewDelegate protocols or it will throw an AppDelegate error as of swift 3
Also please take note of the change in syntax:
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int
is now:
public func numberOfComponents(in pickerView: UIPickerView) -> Int
The following below worked for me.
import UIkit
class ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate {
#IBOutlet weak var textBox: UITextField!
#IBOutlet weak var dropDown: UIPickerView!
var list = ["1", "2", "3"]
public func numberOfComponents(in pickerView: UIPickerView) -> Int{
return 1
}
public func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int{
return list.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
self.view.endEditing(true)
return list[row]
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
self.textBox.text = self.list[row]
self.dropDown.isHidden = true
}
func textFieldDidBeginEditing(_ textField: UITextField) {
if textField == self.textBox {
self.dropDown.isHidden = false
//if you don't want the users to se the keyboard type:
textField.endEditing(true)
}
}
}
Using UIPickerview is the right way to go to implement it according to Apple's Human Interface Guidelines
If you select drop down in mobile safari it will show UIPickerview to let the use choose drop down items.
Alternatively
you can use UIPopoverController till iOS 9 as its deprecated but its better to stick with UIModalPresentationPopover of view you want o show as well
you can use UIActionsheet to show the items but it's better to use UIAlertViewController and choose UIActionSheetstyle to show as the former is deprecated in latest versions
I am pretty new to programming and I am trying to insert a picker view. I think my code is right, but when I build the app it is blank. I have no idea what I am doing wrong.
My code is as follows:
import UIKit
class LookingController: UIViewController, UIPickerViewDelegate {
var iama=["dude","lady"]
func numberOfComponentsInPickerView(pickerView: UIPickerView!) ->Int{
return 1
}
func pickerView(pickerView: UIPickerView!, numberOfRowsInComponent component: Int) ->Int {
return iama.count
}
func pickerView(pickerView: UIPickerView!, titleForRow row: Int, forComponent component: Int)->String!{
return iama[row]
}
}
Any suggestions??
I think you forgot to add pickerView into your view so follow this step.
Go to the Storyboard, drag a Picker View from the Object Library to the top of the View Controller inside the Storyboard.
The Storyboard should look like this.
The Picker View must conform to the UIPickerViewDataSource and UIPickerViewDelegate protocol. Ctrl-click the Picker View and drag from the dataSource Outlet to the View Controller in the Document Outline. Repeat this step for the delegate Outlet.
from the reference : http://www.ioscreator.com/tutorials/picker-view-tutorial-ios8-swift
May be this will help you.