Using ZXing (QR Code Scanner) in Xamarin Forms
For using Zxing in Xamarin Forms we have to first add nuget to both project which are Droid and iOS.
After adding nuget to our project in Droid project open MainActivity.cs and add below code to class
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, Permission[] grantResults) {
ZXing.Net.Mobile.Android.PermissionsHandler.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}