BarcodeScanner.XF

BarcodeScanner using GoogleVision API for Xamarin Form Works on Android and iOS 10+

For Android, it use Xamarin.GooglePlayServices.Vision For iOS, it use GoogleMobileVision under MLKit library

Please feel free to improve my source code.

Pending to fix

1. CameraView is not shown in Android 10 device

Update on 4.2.1.3

1. Added ask permission methods
2. Added IsTorchOn methods
3. Added DefaultTorchOn property
4. Moved some code on iOS to UIThread
5. Added VibrationOnDetected property
6. Run OnDetected event on UIThread
7. Added 1 second interval on iOS scanning to solve double scanning problem
8. Allow continuous scanning
9. Auto switch off flashlight when page dispose

Installation

1. Install Nuget package to Forms, Android and iOS project

Install-Package BarcodeScanner.XF

Android setup

1. Manifest.xml

<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.FLASHLIGHT" />
<uses-permission android:name="android.permission.CAMERA" />

2. Init the library in MainActivity.cs

  base.OnCreate(savedInstanceState);
...
  GoogleVisionBarCodeScanner.Droid.RendererInitializer.Init();
  Plugin.CurrentActivity.CrossCurrentActivity.Current.Init(this, savedInstanceState);
...
  global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
  LoadApplication(new App());

public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
{
    Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
    Plugin.Permissions.PermissionsImplementation.Current.OnRequestPermissionsResult(requestCode, permissions, grantResults);
    base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}

iOS Setup

1. Edit Info.plist, add camera rights

	<key>NSCameraUsageDescription</key>
	<string>Require to use camera</string>

2. Create an project in Google Firebase Console, download GoogleService-Info.plist https://console.firebase.google.com/

3. Put GoogleService-Info.plist into Resources folder of iOS project, set Build Action as BundleResource

4. Init project and firebase on AppDelegate.cs

            global::Xamarin.Forms.Forms.Init();
            LoadApplication(new App());
            ....
            GoogleVisionBarCodeScanner.iOS.Initializer.Init();
            Firebase.Core.App.Configure();
            ....
            return base.FinishedLaunching(app, options);

Usage

1. Set support barcode format (Default is all), call it before you start to init CameraView

GoogleVisionBarCodeScanner.Methods.SetSupportBarcodeFormat(BarcodeFormats.QRCode);

2. It is all about the camera view, use it on the page.xaml. For now, it will spend your whole width of the screen and the height will be equal to width.

VirbationOnDetected: Indicate the device will vibrate or not when detected barcode, default is True

DefaultTorchOn: Indicate the torch will on or not when the view appear, default is False

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:d="http://xamarin.com/schemas/2014/forms/design"
             xmlns:gv="clr-namespace:GoogleVisionBarCodeScanner;assembly=GoogleVisionBarCodeScanner"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             mc:Ignorable="d"
             x:Class="SampleApp.Page1">
   <ContentPage.Content>
     <ScrollView HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
	 <!--If true on DefaultTorchOn, Torch will be on when the UI loaded-->
             <gv:CameraView HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" OnDetected="CameraView_OnDetected" Grid.Row="1"
                            DefaultTorchOn="True" VirbationOnDetected="False"/>
     </ScrollView>
   </ContentPage.Content>
</ContentPage>

3. Once barcode detected, "OnDetected" event will be triggered, do the stuff you want with the barcode, it will contains type and display value

   private async void CameraView_OnDetected(object sender, GoogleVisionBarCodeScanner.OnDetectedEventArg e)
        {
            List<GoogleVisionBarCodeScanner.BarcodeResult> obj = e.BarcodeResults;

            string result = string.Empty;
            for(int i = 0; i < obj.Count; i++)
            {
                result += $"{i + 1}. Type : {obj[i].BarcodeType}, Value : {obj[i].DisplayValue}{Environment.NewLine}";
            }
            Device.BeginInvokeOnMainThread(async() =>
            {
                await DisplayAlert("Result", result, "OK");
                await Navigation.PopModalAsync();
            });
            
        }

4. To use torch, please call

   GoogleVisionBarCodeScanner.Methods.ToggleFlashlight();

5. To ask for permission

bool allowed = await GoogleVisionBarCodeScanner.Methods.AskForRequiredPermission();

6. To check the condition of torch

   GoogleVisionBarCodeScanner.Methods.IsTorchOn();

7. Continuous scanning

   1. Do not dispose the page after onDetected.
   2. Call GoogleVisionBarCodeScanner.Methods.Reset() to scan next.