Xamarin forms Barcode Scanner

You can try the code below. Add the zxing library/component to all the projects in the solution

public class Home : ContentPage
{
    string message = "";
    public Home()
    {
        //Intialize the button
        Button btnScan = new Button
        {
            Text = "Start Scan",
            BackgroundColor = Color.FromRgb(207, 197, 159),
            TextColor = Color.White,
            BorderRadius = 5,
            TranslationY = 120
        };
        //Attach the click event
        btnScan.Clicked += btnScan_Clicked;

        this.Content = new StackLayout
        {
            BackgroundColor = Color.FromRgb(150, 172, 135),
            Spacing = 10,
            Padding = 25,
            Children =
            {
                btnScan
            }
        };
    }

    async void btnScan_Clicked(object sender, EventArgs e)
    {
        var scanner = new MobileBarcodeScanner();
        scanner.TopText = "Hold the camera up to the barcode\nAbout 6 inches away";
        scanner.BottomText = "Wait for the barcode to automatically scan!";

        //This will start scanning
        ZXing.Result result = await scanner.Scan();

        //Show the result returned.
        HandleResult(result);
    }

    void HandleResult(ZXing.Result result)
    {
        var msg = "No Barcode!";
        if (result != null)
        {
            msg = "Barcode: " + result.Text + " (" + result.BarcodeFormat + ")";
        }

        DisplayAlert("", msg, "Ok");
    }
}

You can use ZXing.Net.Mobile.Forms. But you attention.

1. ZXing.Net.Mobile.Forms current version is 2.4.1. I used this version and build failed on Xamarin.Forms.Android project. => Crash App.

   => I used version 2.3.2. It working fine.

2. In Android project file MainActivity.cs, you add following code:

   public override void OnRequestPermissionsResult(int requestCode, string[] permissions, Permission[] grantResults)
   {
       global::ZXing.Net.Mobile.Forms.Android.PermissionsHandler.OnRequestPermissionsResult(requestCode, permissions, grantResults);
   }
   

   It seems, the tutorial code on here is incorrect

3. Call scanner:

   private async void BtnScan_OnClicked(object sender, EventArgs e)
   {
       ZXingScannerPage scanPage = new ZXingScannerPage();
       scanPage.OnScanResult += (result) =>
       {
           scanPage.IsScanning = false;
           Device.BeginInvokeOnMainThread(() =>
           {
               Navigation.PopAsync();
               EtInputCode.Text = "Code: " + result.Text;
           });
       };
       await Navigation.PushAsync(scanPage);
   }
   

You can use ZXing.Net.Mobile nuget. The library is available in github in the following URL https://github.com/Redth/ZXing.Net.Mobile. You'll find a usage documentation in the first page. But I'll explain it brievelly in 3 steps as follows :

1. Add the nuget to your project

2. Create a ContentPage. In the xaml side, create a button or an image button. In the following exemple, I'm using like an image button like this :

   <ImageButton  x:Name="ScanButton"  Source="scannimage.png"  />
   

3. In the code bind, put the following code in the constructor or in the OnAppearing() method:

   ScanButton.Clicked += async (sender, e) =>
   {
       var scanner = new ZXing.Mobile.MobileBarcodeScanner();
       var result = await scanner.Scan();
   
       if (result != null)
       {
           await DisplayAlert("Code barre", "Scanned Barcode: " + result.Text, "Ok");
       }
   };