I'm trying to make a single UIPickerView with 2 components, each with a different amount of rows. I thought that I could base the row number per component on the index of the component, but when I run my app the UIPickerView displays only one single blank row and doesn't allow scrolling.
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 2
}
// grades is a 2D array
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return grades[component].count
}
// level and letter are predefined ints
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if component == 0 {
level = row
}else if component == 1 {
letter = row
}
return ""
}
EDIT:
This is my viewDidLoad()
override func viewDidLoad() {
super.viewDidLoad()
pickerView.dataSource = self;
pickerView.delegate = self;
}
I believe you should return non-empty title to make it work
...
// level and letter are predefined ints
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if component == 0 {
level = row
} else if component == 1 {
letter = row
}
return "Component: \(component) Row: \(row)" // whatever string you want to display
}
Related
What would be the best way to get the value from a PickerView without having a datasource? So i can not read values from i.e. an array.
Current values are just row numbers, that i need to read after user is done with picking.
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 3
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if component == 0 {
return 300
} else {
return 10
}
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if component == 0 {
return "\(row)."
} else {
return "\(row)"
}
}
You can use pickerView.selectedRow(inComponent:)
let firstValue = pickerView.selectedRow(inComponent: 0)
let secondValue = pickerView.selectedRow(inComponent: 1)
Both will just be an Int value representing the currently selected row index in it's respective component. And since your values are starting from 0, you can use the values directly.
You simply add this func:
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
print(row)
}
Just take care that row starets at 0
Trying to fill two labels using single UIPicker. It has one column, two labels which have two buttons at the end of each label. On clicking which the UIPicker view is shown
#IBOutlet weak var userLoc1: UILabel!
#IBOutlet weak var userLoc2: UILabel!
let location = ["location1", "Location2", "Location3",
"Location4", "Location5", "Location6", "Location7"]
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
var countRow:Int = 0
if pickerView == LocationPickerView{
countRow = self.location.count
}
return countRow
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if pickerView == LocationPickerView
{
let titleLocation = location[row]
return titleLocation
}
return ""
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if pickerView == LocationPickerView
{
selectedLocation1 = self.location[row]
self.userLoc1.text = self.location[row]
self.LocationPickerView.isHidden = true
//anything that can be done here that can assign different values to
//two label using the same UIPicker
}
Any guide to resolve the matter is greatly appreciated
Just add an extra column to your picker view and then add a second array to fill that new column.
It's all the same methods used to initialise the pickerview just with a bit of added logic.
let location1 = ["location1", "Location2", "Location3",
"Location4", "Location5", "Location6", "Location7"]
let location2 = ["location8", "Location9", "Location10",
"Location11", "Location12", "Location13", "Location14"]
// Set number of columns in your picker view
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 2
}
// Set number of rows of each column to length of arrays
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
switch component {
case 0:
return self.location1
case 1:
return self.location2
default: break
}
}
// Set content of rows in each column
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
switch component {
case 0:
return self.location1[row]
case 1:
return self.location2[row]
default: break
}
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if pickerView == LocationPickerView
{
switch component {
case 0:
selectedLocation1 = self.location1[row]
self.userLoc1.text = self.location1[row]
case 1:
selectedLocation2 = self.location2[row]
self.userLoc2.text = self.location2[row]
default: break
}
self.LocationPickerView.isHidden = true
}
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 {
...
}
}
If I want to have the default row when the view controller starts as [2] or any other row number, how do I carry that out?
var pickerData = ["2x2","4x4","6x6","8x8","12x12"]
override func viewDidLoad() {
super.viewDidLoad()
totalTilesLabel.text = pickerData[8]
display.text = sentData
self.picker.delegate = self
self.picker.dataSource = self
}
This is the UIPicker datasource and delegate.
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return pickerData.count
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return pickerData[row]
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
}
Set the picker view's selected row to whatever initial row you want in the viewDidLoad method. Here's Swift 3 code. Adjust as needed for Swift 2.
self.picker.selectRow(8, inComponent: 0, animated: false)
I have a two column picker (Miles and Tenths)
Picker seems to work well, but I cannot seem to work out how to concatenate the selections from the two columns i.e. if user selects 23 from first column and 6 from second column, I want to create an answer of "23.6"
At the moment, either column selection overwrites the previous selection.
BTW: I don't think I can append two strings because what happens if user selects the 10ths first?
let resetPickerData = [Array(0...99), Array(0...9)]
// returns the number of 'columns' to display.
func numberOfComponentsInPickerView(pickerView: UIPickerView!) -> Int{
return 2
}
// returns the # of rows in each component..
func pickerView(pickerView: UIPickerView!, numberOfRowsInComponent component: Int) -> Int{
return resetPickerData[component].count
}
func pickerView(pickerView: UIPickerView!, titleForRow row: Int, forComponent component: Int) -> String! {
return String(resetPickerData[component][row])
}
func pickerView(pickerView: UIPickerView!, didSelectRow row: Int, inComponent component: Int)
{
//var distance = ??
}
You'll need to keep track of the component selection separately like this then concant the strings:
var firstComponentString = ""
var secondCompoentString = ""
func pickerView(pickerView: UIPickerView!, didSelectRow row: Int, inComponent component: Int)
{
if component == 0 {
firstComponentString = String(resetPickerData[component][row])
}
else if component == 1 {
secondCompoentString = String(resetPickerData[component][row])
}
var displayString = "\(firstComponentString).\(secondCompoentString)"
}