Generate QR Code for iOS

qrcode.swift

import CoreImage
import UIKit

static func generateQRCode(url: String) -> UIImage? {

    let data = url.data(using: .utf8)!
    let params: [String: Any] = [
        "inputMessage": data,
        "inputCorrectionLevel": "L"
    ]
    let filter = CIFilter(name: "CIQRCodeGenerator", withInputParameters: params)

    guard let image = filter?.outputImage else {
        return nil
    }
    guard let cgImage = CIContext().createCGImage(image, from: image.extent) else {
        return nil
    }

    let size = CGSize(width: 150, height: 150)
    UIGraphicsBeginImageContextWithOptions(size, true, 0)
    let ctx = UIGraphicsGetCurrentContext()
    ctx?.interpolationQuality = .none
    ctx?.draw(cgImage, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
    let resized = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return resized
}

Eq エンジニアブログ: iOS - QRコードの読み取り/生成 (iOS11)