NEW: My new book Pro SwiftUI is out now – level up your SwiftUI skills today! >>

How to use UIPickerView

Swift version: 5.6

Paul Hudson    @twostraws   

The spinning, barrel-shaped picker view has been a hallmark component of iOS since the first iPhone, and it doesn’t take much work for you to use in your own apps.

First, create and position a UIPickerView where you want it. This code creates one at the bottom of the screen:

let picker = UIPickerView()
picker.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(picker)

picker.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor).isActive = true
picker.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor).isActive = true
picker.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor).isActive = true

Now decide what should be the data source and delegate for the picker view. Traditionally these are there to provide data (the data source) and respond to actions (the delegate), but UIPickerView gets these two confused so you really need both.

To make things easy here we’re going to use your existing view controller for both data source and delegate, but you should move this code elsewhere in your own projects. So, start by adding both UIPickerViewDataSource and UIPickerViewDelegate to the conformance list for your view controller.

Finally, implement three methods: numberOfComponents() describes how many individual segments there are in the picker view, numberOfRowsInComponent describes how many rows each segment has, and titleForRow provides the title for each row in each segment.

Here’s some example code to get you started:

func numberOfComponents(in pickerView: UIPickerView) -> Int {
    return 2
}

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    if component == 0 {
        return 10
    } else {
        return 100
    }
}

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    if component == 0 {
        return "First \(row)"
    } else {
        return "Second \(row)"
    }
}
Hacking with Swift is sponsored by Play

SPONSORED Play is the first native iOS design tool created for designers and engineers. You can install Play for iOS and iPad today and sign up to check out the Beta of our macOS app with SwiftUI code export. We're also hiring engineers!

Click to learn more about Play!

Sponsor Hacking with Swift and reach the world's largest Swift community!

Available from iOS 2.0

Similar solutions…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

BUY OUR BOOKS
Buy Pro Swift Buy Pro SwiftUI Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let us know!

Average rating: 3.6/5

 
Unknown user

You are not logged in

Log in or create account
 

Link copied to your pasteboard.