how to make ZxingScanner start scanning?

Question

I am trying to implement barcode scanning in my Xamarin form, but no success.
I am able to get the camera working, but I don't see the red line on the screen and it simply refuses to scan anything

I tried this answer. I can see thru my camera, but no red line appears. But I can put the torch on and off

XAML code:

<Button  BackgroundColor="Chocolate" Clicked="Button_Clicked"/>
<zxing:ZXingScannerView 
    x:Name="_scanView" 
    OnScanResult="Handle_OnScanResult" 
    IsScanning="true" 
    IsAnalyzing="true"
    WidthRequest="200" 
    HeightRequest="200" />

C# Code:

private void Button_Clicked(object sender, EventArgs e)
{
    _scanView.ToggleTorch();
}

private void Handle_OnScanResult(ZXing.Result result)
{
    ChassisEntry.Text = result.Text;
}


// this is in the constructor of the page
MobileBarcodeScanningOptions options = new ZXing.Mobile.MobileBarcodeScanningOptions()
{
    TryHarder = true,
    PossibleFormats = new List<ZXing.BarcodeFormat>() { ZXing.BarcodeFormat.All_1D }
};
_scanView.Options = options;

What am I missing ?

EDIT

I have this in my MainActivity.cs

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);

    Xamarin.Essentials.Platform.Init(this, savedInstanceState);
    global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
    ZXing.Net.Mobile.Forms.Android.Platform.Init();
    LoadApplication(new App());
}

public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
{
   Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
   ZXing.Net.Mobile.Forms.Android.PermissionsHandler.OnRequestPermissionsResult(requestCode, permissions, grantResults);

   base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}

Addition to the answer

@Rafeal 's answer is working for me, the only problem is that there is no red line on the scan view.
I found this workaround for that problem.
However, it is a workaround because I notice that the scan already happens if the barcode is anywhere in the view.
Though this might not appear a problem, in my case I have paper forms with up to 20 barcodes on it, and when the user wants to aim at a particular barcode he might get the wrong one.

So if anybody knows a better solution I would like to hear it.
I will make a separate question on SO about this problem.

This is the workaround I am using now

  <Grid VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand">
                <zxing:ZXingScannerView
                    x:Name="_scanView"
                    OnScanResult="Handle_OnScanResult"
                    IsScanning="true"
                    WidthRequest="200"
                    HeightRequest="200"/>


                <zxing:ZXingDefaultOverlay
                    x:Name="scannerOverlay"                                                       
                    BottomText="Place the red line over the barcode you'd like to scan.">

                </zxing:ZXingDefaultOverlay>
            </Grid>

Answer 1

In my working project I used this xaml declaration:

<zxing:ZXingScannerView x:Name="qrCodeScannerView" 
                        OnScanResult="Handle_OnScanResult" 
                        IsScanning="true"
                        WidthRequest="1024" 
                        HeightRequest="400" />

Note, that I did not set isAnalyzing property in the xaml declaration as you did. As the page appears, the zxing control starts working and analyzing immediately.

Then in xaml.cs file

        public void Handle_OnScanResult(Result scanResult)
        {
                qrCodeScannerView.IsScanning = false;
                // processing scanResult.Text here
        }

        protected override void OnAppearing()
        {
            base.OnAppearing();
            qrCodeScannerView.IsScanning = true;
        }

        protected override void OnDisappearing()
        {
            base.OnDisappearing();
            qrCodeScannerView.IsScanning = false;
        }

That looks strange, but setting isScanning property also in xaml.cs file solved this task for me.

Answer 2

Try removing the ZXingScannerView from your XAML completely. On a clicked event of a button add this code:

private async void ButtonScan(object sender, EventArgs e)
{
    PermissionStatus granted = await Permissions.CheckStatusAsync<Permissions.Camera>();
    if (granted != PermissionStatus.Granted)
    {
        _ = await Permissions.RequestAsync<Permissions.Camera>();
    }
    if (granted == PermissionStatus.Granted)
    {
        try
        {
            MobileBarcodeScanner scanner = new MobileBarcodeScanner();
            ZXing.Result result = await scanner.Scan();
            if (result != null && result.Text != "")
            {
                //You access your scanned text with result.Text
                scanner.Cancel(); // <--- This closes the scanner
            }
        }
        catch (Exception)
        {
            await DisplayAlert("Problem", "Something went wrong.", "ΟΚ");
        }
    }
    else
    {
        await DisplayAlert("Problem", "No permissions to use camera.", "ΟΚ");
    }
} 

EDIT

OP mentioned i should add this line of code to my answer in order to make it work.

In the MainActivity.cs you have to initialize the scanner like this:

ZXing.Mobile.MobileBarcodeScanner.Initialize(Application);