NEW! Master Swift design patterns with my latest book! >>

How to create a barcode

Paul Hudson       @twostraws

You can generate a string into a traditional barcode using iOS using Core Image, but you should make sure and convert your input string to a Data using String.Encoding.ascii to ensure compatibility. Here's a function you can use that wraps it all up neatly, including scaling up the barcode so it's a bit bigger:

func generateBarcode(from string: String) -> UIImage? {
    let data = string.data(using: String.Encoding.ascii)

    if let filter = CIFilter(name: "CICode128BarcodeGenerator") {
        filter.setValue(data, forKey: "inputMessage")
        let transform = CGAffineTransform(scaleX: 3, y: 3)

        if let output = filter.outputImage?.transformed(by: transform) {
            return UIImage(ciImage: output)
        }
    }

    return nil
}

With that method in place, you can now write code like this:

let image = generateBarcode(from: "Hacking with Swift")

Available from iOS 8.0

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

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

Get my latest video for free

Learn about value types, functional programming, and protocol-oriented programming in this new video – it's free!

MASTER SWIFT NOW
Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Practical iOS 11 Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Click here to visit the Hacking with Swift store >>