Please recheck your filename and path. Make sure the password.txt already exist at that location

var path = System.Environment.GetFolderPath(System.Environment.SpecialFolder.MyDocuments);
string filename = Path.Combine(path, "password.txt");

You can check the file path by:

Android.Util.Log("Hello", $"file path {filename}");

Note:
System.Environtment is rarely used when developing with Xamarin.Android, use Android.OS.Environtment instead.

Hello all,
@DimChris i'm not sure to well understand, you'd like to find when the user browse over the items in the listview start an animation ? or a loader ?

i've find a sample in java about recycler view and animation here is it the link
https://www.androidhive.info/2018/01/android-content-placeholder-animation-like-facebook-using-shimmer/

it s not good solution but its working for me

int page_count = 0;

void NextPage()
        {
            int mCount = mListView.Count;

            if (page_count + 5 < mCount)
            {
                page_count += 5;
                mListView.SmoothScrollBy(200, 0);//necessery 
                mListView.SmoothScrollToPositionFromTop(page_count, 0);
            }
        }

        void PrevPage()
        {
            if (page_count != 0)
            {
                page_count -= 5;

                mListView.SmoothScrollToPositionFromTop(page_count, 0);
            }
        }

@xama.m

Can any one help me on Pagination on Scrolling of ListView In xamarin.Android

Do you want to implement "Load more items" when the listview scroll to the end?
If so, you could set IOnScrollListener to the listview.
If the listview is scrolled to the end, add the new item to the listview.
Please check the following link for more information:
https://stackoverflow.com/questions/16398921/dynamic-listview-adding-load-more-items-at-the-end-of-scroll

Hi @MarioFumagalli

Not sure if you're still trying to get this to work, but I have managed to get it working by doing my own mapping.

So instead of trying to get the Firebase library to serialize/deserialize my POCO classes, I instead created a map of each POCO to map to and from a Java.Util.HashMap.

So to save data, in this case a new contact...

var contactsRef = App.Current.FirebaseDatabase.GetReference(Settings.GetContactRef(App.Current.CurrentUserId));

//save new contact
_contact = new ContactModel
 {
    Uid = Guid.NewGuid().ToString(),  //temp key
    FirstName = _txtFirstName.Text.Trim(),
    LastName = _txtLastName.Text.Trim(),
    PhoneNumber = _txtPhone.Text.Trim(),
    DefaultContact = _swPrimary.Checked
};
contactsRef.Push().SetValue(_contact.ContactModelToMap()).AddOnCompleteListener(this);

Then to map data received from Firebase...

...
var contactsRef = App.Current.FirebaseDatabase.GetReference(Settings.GetContactRef(App.Current.CurrentUserId));
            contactsRef.AddValueEventListener(this);
...

public void OnDataChange(DataSnapshot snapshot)
{
    _contacts = new List<ContactModel>();
    var obj = snapshot.Children;
    foreach (DataSnapshot s in obj.ToEnumerable())
    {
        var model = s.MapToContactModel();

        if (model != null)
            _contacts.Add(model);
    }
}

Note that you need to implement IValueEventListener on your Activity/Fragment

And here's my code for mapping a POCO to a HashMap, and a DataSnapShot to a POCO.

public static HashMap ContactModelToMap(this ContactModel model)
        {
            HashMap map = new HashMap();
            map.Put("Uid", model.uId);
            map.Put("FirstName", model.FirstName);
            map.Put("LastName", model.LastName);
            map.Put("PhoneNumber", model.PhoneNumber);
            map.Put("DefaultContact", model.DefaultContact);

            return map;
        }

        public static ContactModel MapToContactModel(this DataSnapshot snapShot)
        {
            ContactModel model = new ContactModel();

            if (snapShot.GetValue(true) == null) return null; // key, but no value, recently deleted. Return null.

            model.uId = snapShot.Key;
            model.FirstName = snapShot.Child("FirstName")?.GetValue(true)?.ToString();
            model.LastName = snapShot.Child("LastName")?.GetValue(true)?.ToString();
            model.PhoneNumber = snapShot.Child("PhoneNumber")?.GetValue(true)?.ToString();

            bool defaultContact;
            bool.TryParse(snapShot.Child("DefaultContact")?.GetValue(true).ToString(), out defaultContact);
            model.DefaultContact = defaultContact;

            return model;
        }

This is obviously not the most efficient implementation, but it seems to be adequate for my app. Also supports offline use out-of-the-box which is cool.

Now to try with iOS....