PickPhotoAsync - the first time it doesn't work - xamarin

Question

The first time I use the application after confirming the permission to access the photos saved on the gallery, pickphoto async seems to do nothing.
in my opinion the problem is that it does not wait for user authorization.
in order to work correctly I have to click on the upload button of the photo more than once.
i am working with android with the latest version of the library.
await CrossMedia.Current.Initialize();
if (!CrossMedia.Current.IsPickPhotoSupported)
{
await DisplayAlert("Oops", "You Cannot pick an image", AppResources.Label_OK);
return;
}
var file = await CrossMedia.Current.PickPhotoAsync(new PickMediaOptions
{
PhotoSize = PhotoSize.MaxWidthHeight,
MaxWidthHeight = 800,
SaveMetaData = false
});

Answer 1

You could ask for the runtime permission before you load the page. After that, you do not need to click on the upload button of the photo more than once.
protected override void OnAppearing()
{
base.OnAppearing();
RunTimePermission();//ask for the runtime permission
}

Answer 2

I thank the people who answered me.
I found the error:
Wrong Code:
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, Permission[] grantResults)
{
PermissionsImplementation.Current.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}
Correct code:
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Permission[] grantResults)
{
Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}