Android : deleting listview in xamarin android

hi i had a problem deleting items in listview on android, im using xamarin android, i have a custom row that has delete button, but when i click on it, deleting the last item not the selected item.

here is my code

public override View GetView(int position, View convertView, ViewGroup parent)
    {
        Button btnDelete;
        var item = _items[position];
        var view = convertView;
        if (view == null)
        {
            view = _content.LayoutInflater.Inflate(Resource.Layout.CustomRow, null);
            view.FindViewById<TextView>(Resource.Id.PostTitle).Text = item.PostTitle;
            view.FindViewById<TextView>(Resource.Id.PostMessage).Text = item.PostMessage;
            view.FindViewById<TextView>(Resource.Id.PostDate).Text = item.PostDate;
            view.FindViewById<TextView>(Resource.Id.AuthorName).Text = item.AuthorName;
            view.FindViewById<ImageView>(Resource.Id.PostAvatar).SetImageResource(item.ImageResourceId);
            view.FindViewById<TextView>(Resource.Id.Date_Read).Text = item.DateRead;
            btnDelete = view.FindViewById<Button>(Resource.Id.btnDelete);
            btnDelete.Click += (sender, args) =>
            {
                var delPos = (int) (((Button) sender).GetTag(Resource.Id.btnDelete));
                _items.RemoveAt(delPos);
                NotifyDataSetChanged();
            };
        }
        else
        {
            btnDelete = view.FindViewById<Button>(Resource.Id.btnDelete);

            btnDelete.SetTag(Resource.Id.btnDelete, position);
        }

        return view;
    }

or can u tell me guys how to get the id of the selected row in listview, i think that is the problem.

btnDelete.Click += (sender, args) =>
            {
                var delPos = (int) (((Button) sender).GetTag(Resource.Id.btnDelete));
                _items.RemoveAt(delPos);
                NotifyDataSetChanged();
            };