How to Implement a Flutter QR Code Scanner Plugin for iOS in Swift

Flutter QR Code Scanner Plugin

Dev Environment

  • M1 Mac
  • Xcode 13.2.1

Step-by-step Guide: Implement Flutter QR Code Scanner Plugin for iOS

Step 1: Get the Existing Flutter Plugin Project:

git clone

Step 2: Add Support for iOS

cd flutter_qrcode_scanner
flutter create --template=plugin --platforms=ios .

Step 3: Install Dynamsoft Camera Enhancer and Dynamsoft Barcode Reader

s.dependency 'DynamsoftBarcodeReader', '8.9.1'
s.dependency 'DynamsoftCameraEnhancer', '2.1.1'

Activating Mobile QR Code SDK

Step 4: Implement the Factory and the Platform View Using Swift Code

  1. Based on the structure of the Android QRCodeScanner class, we create a FLQRCodeScanner class in iOS/Classes/FLQRCodeScanner.swift:
import Flutter
import UIKit
import DynamsoftBarcodeReader
import DynamsoftCameraEnhancer

public protocol DetectionHandler {
func onDetected(data: NSArray)

class FLQRCodeScanner: NSObject, DBRTextResultDelegate {

private var cameraView: DCECameraView
private var dce: DynamsoftCameraEnhancer
private var barcodeReader: DynamsoftBarcodeReader! = nil
private var handler: DetectionHandler?

init(cameraView: DCECameraView, dce: DynamsoftCameraEnhancer) {
self.cameraView = cameraView
self.cameraView.overlayVisible = true
self.dce = dce

createBarcodeReader(dce: dce)

func setDetectionHandler(handler: DetectionHandler) {
self.handler = handler;

func createBarcodeReader(dce: DynamsoftCameraEnhancer) {
// To activate the sdk, apply for a license key:
barcodeReader = DynamsoftBarcodeReader.init(license: "license-key")

// Set text result call back to get barcode results.
barcodeReader.setDBRTextResultDelegate(self, userData: nil)

// Start the barcode decoding thread.

func textResultCallback(_ frameId: Int, results: [iTextResult]?, userData: NSObject?) {
if results!.count > 0 {
let outResults = NSMutableArray()
for item in results! {
let subDic = NSMutableDictionary()
if item.barcodeFormat_2 != EnumBarcodeFormat2.Null {
subDic.setObject(item.barcodeFormatString_2 ?? "", forKey: "format" as NSCopying)
subDic.setObject(item.barcodeFormatString ?? "", forKey: "format" as NSCopying)
subDic.setObject(item.barcodeText ?? "", forKey: "text" as NSCopying)
let points = item.localizationResult?.resultPoints as! [CGPoint]
subDic.setObject(Int(points[0].x), forKey: "x1" as NSCopying)
subDic.setObject(Int(points[0].y), forKey: "y1" as NSCopying)
subDic.setObject(Int(points[1].x), forKey: "x2" as NSCopying)
subDic.setObject(Int(points[1].y), forKey: "y2" as NSCopying)
subDic.setObject(Int(points[2].x), forKey: "x3" as NSCopying)
subDic.setObject(Int(points[2].y), forKey: "y3" as NSCopying)
subDic.setObject(Int(points[3].x), forKey: "x4" as NSCopying)
subDic.setObject(Int(points[3].y), forKey: "y4" as NSCopying)
subDic.setObject(item.localizationResult?.angle ?? 0, forKey: "angle" as NSCopying)

if handler != nil {
handler!.onDetected(data: outResults)

func startScan() {
cameraView.overlayVisible = true
import Flutter
import UIKit
import DynamsoftCameraEnhancer

class FLNativeView: NSObject, FlutterPlatformView, DetectionHandler {
private var _view: UIView
private var messenger: FlutterBinaryMessenger
private var channel: FlutterMethodChannel
private var qrCodeScanner: FLQRCodeScanner
frame: CGRect,
viewIdentifier viewId: Int64,
arguments args: Any?,
binaryMessenger: FlutterBinaryMessenger
) {
self.messenger = binaryMessenger
let cameraView = DCECameraView.init(frame: frame)
let dce = DynamsoftCameraEnhancer.init(view: cameraView)
_view = cameraView

qrCodeScanner = FLQRCodeScanner.init(cameraView: cameraView, dce: dce)

channel = FlutterMethodChannel(name: "com.dynamsoft.flutter_camera_qrcode_scanner/nativeview_" + String(viewId), binaryMessenger: messenger)


qrCodeScanner.setDetectionHandler(handler: self)
(call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
switch call.method {
case "startScanning":
case "stopScanning":
case "setLicense":
self.qrCodeScanner.setLicense(license: (call.arguments as! NSDictionary).value(forKey: "license") as! String)
case "setBarcodeFormats":
self.qrCodeScanner.setBarcodeFormats(arg: call.arguments as! NSDictionary)

func view() -> UIView {
return _view

func onDetected(data: NSArray) {
DispatchQueue.main.async {"onDetected", arguments: data)
import Flutter
import UIKit

class FLNativeViewFactory: NSObject, FlutterPlatformViewFactory {
private var messenger: FlutterBinaryMessenger

init(messenger: FlutterBinaryMessenger) {
self.messenger = messenger

func create(
withFrame frame: CGRect,
viewIdentifier viewId: Int64,
arguments args: Any?
) -> FlutterPlatformView {
return FLNativeView(
frame: frame,
viewIdentifier: viewId,
arguments: args,
binaryMessenger: messenger
import Flutter
import UIKit

public class SwiftFlutterCameraQrcodeScannerPlugin: NSObject, FlutterPlugin {
public static func register(with registrar: FlutterPluginRegistrar) {
let factory = FLNativeViewFactory(messenger: registrar.messenger())
registrar.register(factory, withId: "com.dynamsoft.flutter_camera_qrcode_scanner/nativeview")

Step 5: Test the QR code scanner in Flutter

  1. Go to the example folder and add the camera access permission to ios/Runner/Info.plist:
<string>Can I use the camera please?</string>
<string>Can I use the mic please?</string>
flutter run

Source Code




Manager of Dynamsoft Open Source Projects | Tech Lover

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Xiao Ling

Xiao Ling

Manager of Dynamsoft Open Source Projects | Tech Lover

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