Whyt zxing shows black screen in .net maui? - zxing

Question

I'm trying to use the bar code scanning ZXing.Net.Maui from https://github.com/Redth/ZXing.Net.Maui
I add the scanner to a page as follows :
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="myapp.Pages.ControleDesBillets"
x:DataType="viewmodel:StandardPageVM"
xmlns:viewmodel="clr-namespace:myapp.ViewModels"
xmlns:Controls="clr-namespace:myapp.Resources.Controls"
xmlns:zxing="clr-namespace:ZXing.Net.Maui.Controls;assembly=ZXing.Net.MAUI">
<Grid RowDefinitions="*" ColumnDefinitions="*">
<zxing:CameraBarcodeReaderView x:Name="cameraBarcodeReaderView" Grid.Column="0" Grid.Row="0" HeightRequest="200" WidthRequest="200"/>
</Grid>
</ContentPage>
When the app runs, it prompts for the Camera Access which is allowed then it shows a black screen and nothing else.
The scanner is initialized in the start up of the app :
public static MauiApp CreateMauiApp()
{
var builder = MauiApp.CreateBuilder();
builder.UseMauiApp<App>().UseMauiCommunityToolkit();
builder.UseBarcodeReader(); // << here
return builder.Build();
}
I'm testing using a physical device. Here is my output :
Loaded assembly: /data/data/com.companyname.myapp/files/.__override__/Xamarin.Google.Guava.ListenableFuture.dll [External]
[CameraManagerGlobal] Connecting to camera service
[CameraManagerGlobal] [soar.cts] ignore the status update of camera: 2
[CameraManagerGlobal] [soar.cts] ignore the status update of camera: 3
[CameraManagerGlobal] [soar.cts] ignore the status update of camera: 4
[CameraManagerGlobal] [soar.cts] ignore the status update of camera: 5
[CameraManagerGlobal] ignore the torch status update of camera: 3
[CameraManagerGlobal] ignore the torch status update of camera: 4
[CameraMetadataJV] setAppNameAndSensorId all [com.antutu:0,ssize,12032x9024,0,false]
[CameraMetadataJV] setAppNameAndSensorId all [com.antutu:1,ssize,5184x3880,0,false]
[CameraRepository] Added camera: 0
[Camera2CameraInfo] Device Level: INFO_SUPPORTED_HARDWARE_LEVEL_3
[CameraRepository] Added camera: 1
[Camera2CameraInfo] Device Level: INFO_SUPPORTED_HARDWARE_LEVEL_3
[CameraValidator] Verifying camera lens facing on rain, lensFacingInteger: null
Thread finished: <Thread Pool> #2
Thread finished: <Thread Pool> #4
Le thread 0x2 s'est arrêté avec le code 0 (0x0).
Le thread 0x4 s'est arrêté avec le code 0 (0x0).
[CompatibilityChangeReporter] Compat change id reported: 150939131; UID 10378; state: ENABLED
Does anyone know what am I doing wrong please ?
Thanks.
Cheers,

Answer 1

Its a known issue : https://github.com/Redth/ZXing.Net.Maui/issues/7
Zxing be it XF or MAUI has always been trash. It's either slow, low performant or has random issues and almost no good features.
There is another BarcodeScanner based on MLKit that's the literal opposite of what I mentioned above.
Installation Steps here: https://github.com/JimmyPun610/BarcodeScanner.Mobile/wiki/3.-Installation-for-Maui
Once you have installed it and have the basic setup ready all you have to do is something like below:
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="SampleApp.Maui.Page1"
xmlns:gv="clr-namespace:BarcodeScanner.Mobile.Maui;assembly=BarcodeScanner.Mobile.Maui"
Title="Page1">
<ContentPage.Content>
<!--VirbationOnDetected: Indicate the device will vibrate or not when detected barcode, default is True
TorchOn: Indicate the torch will on or not when the view appear, default is False
IsScanning : Indicate whether the device will start scanning after it is opened, default is True
RequestedFPS: Affect Android only, remove it if you want a default value (https://developers.google.com/android/reference/com/google/android/gms/vision/CameraSource.Builder.html#public-camerasource.builder-setrequestedfps-float-fps)
ScanInterval: Scan interval for iOS, default is 500ms and the minimum is 100ms, please be reminded that double scanning may be occurred if it is too small
-->
<gv:CameraView HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" OnDetected="CameraView_OnDetected" Grid.Row="1"
TorchOn="False" VibrationOnDetected="False" ScanInterval="50" x:Name="Camera"/>
</ContentPage.Content>
</ContentPage>
And you are done. Hope this helps!

Answer 2

When I push page with camera view, wrapped in NavigationPage, then it freezes.
await Shell.Current.Navigation.PushModalAsync(new NavigaionPage(new ScannerPage), false);
But pushing page by itself works fine no problems
await Shell.Current.Navigation.PushModalAsync(new ScannerPage(), false);