Xamarin создает проблему с ViewModel и хранилищем для инъекций в эту модель для вставки в базу данных

Question

У меня проблема с внедрением зависимостей в ViewModel. Я создал CustomerViewModel, и мне нужно вставить здесь ICustomerRepository для выполнения действия Entity Framework, например, вставить пользователя в локальную базу данных.

Вопрос: Как прикрепить (внедрить) ICustomersRepository в мою модель представления для вставки / обновления ... клиентов

Вот мой CustomerViewModel.cs:

using PropertyChanged;
using System;
using System.Threading.Tasks;
using System.Windows.Input;
using Xamarin.Forms;

namespace RodoAcceptance
{
    [AddINotifyPropertyChangedInterface]
    public class CustomerViewModel : BaseViewModel
    {
        #region Private Members

        private readonly ICustomersRepository _customersRepository;

        #endregion

        #region Constructors

        /// <summary>
        /// Default constructor
        /// </summary>
        /// <param name="customersRepository">An instance of <see cref="ICustomersRepository"/></param>
        public CustomerViewModel()
        {

        }

        #endregion

        /// <summary>
        /// Element ID
        /// </summary>
        public int Id { get; set; }

        /// <summary>
        /// User rules accepted
        /// </summary>
        public bool IsAccepted { get; set; }

        /// <summary>
        /// User fullname
        /// </summary>
        public string FullName { get; set; }

        /// <summary>
        /// User birthday
        /// </summary>
        public DateTime? Birthday { get; set; } = new DateTime(2000, 1, 1);

        /// <summary>
        /// Signature wrapper
        /// </summary>
        public byte[] Signature { get; set; }

        /// <summary>
        /// Customer model
        /// </summary>
        public Customer Customer { get; set; }

        /// <summary>
        /// User signature Stream
        /// </summary>
        public Func<Task<byte[]>> SignatureFromStream { get; set; }

        /// <summary>
        /// Add new customer to database
        /// </summary>
        public ICommand AddCustomerCommand => new Command(async () =>
        {
            Signature = await SignatureFromStream();
            // Signature should be != null

            var customer = new Customer()
            {
                FullName = this.FullName,
                IsAccepted = this.IsAccepted,
                Birthday = this.Birthday
            };

            if(Signature != null)
            {
                customer.Image = this.Signature.ToString();
            }
            else
            {
                await Application.Current.MainPage.DisplayAlert("Błąd", "Nie wszystkie pola zostały poprawnie wypełnione", "OK");
                return;
            }

            await _customersRepository.AddCustomerAsync(customer);
        });
    }  
}

BottomBarPage.cs MainPage наследуется от этого класса

using Xamarin.Forms;

namespace RodoAcceptance
{
    public class BottomBarPage : TabbedPage
    {
        private bool _tabIndexSet = false;

        /// <summary>
        /// Default constructor
        /// </summary>
        public BottomBarPage()
        {

        }

        public enum BarThemeTypes { Light, DarkWithAlpha, DarkWithoutAlpha }

        public bool FixedMode { get; set; }

        public BarThemeTypes BarTheme { get; set; }

        public void RaiseCurrentPageChanged()
        {
            OnCurrentPageChanged();
        }

        /// <summary>
        /// When the page change event is rised
        /// </summary>
        protected override void OnCurrentPageChanged()
        {
            base.OnCurrentPageChanged();

            // Get current tab index
            var index = Children.IndexOf(CurrentPage);

            // Check if page is loaded first time
            // If page is not loaded first time...
            if (_tabIndexSet)
            {
                // Set Customers page
                if (index == 0)
                {
                    // change binding context
                    CurrentPage.BindingContext = new CustomerViewModel();
                }
                // Set Customers List page
                else if (index == 1)
                {
                    // change binding context
                    CurrentPage.BindingContext = new CustomersListViewModel();
                }
            }
            // If page is loaded first time...
            else
            {
                _tabIndexSet = true;
            }
        }
    }
}

CustomersRepository.cs

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace RodoAcceptance
{
    public class CustomersRepository : ICustomersRepository
    {
        /// <summary>
        /// Default database context
        /// </summary>
        private readonly DatabaseContext _databaseContext;

        /// <summary>
        /// Default constructor
        /// </summary>
        /// <param name="databaseContext">Database context to connect</param>
        public CustomersRepository(string databaseContext)
        {
            _databaseContext = new DatabaseContext(databaseContext);
        }

        public async Task<IEnumerable<Customer>> GetCustomersAsync()
        {
            try
            {
                var customers = await _databaseContext.Customers.ToListAsync();

                return customers;
            }
            catch (Exception e)
            {
                return null;
            }
        }

        public async Task<Customer> GetCustomerByIdAsync(int id)
        {
            try
            {
                var customer = await _databaseContext.Customers.FindAsync(id);

                return customer;
            }
            catch (Exception e)
            {
                return null;
            }
        }

        public async Task<bool> AddCustomerAsync(Customer customer)
        {
            try
            {
                var tracking = await _databaseContext.Customers.AddAsync(customer);

                await _databaseContext.SaveChangesAsync();

                var isAdded = tracking.State == EntityState.Added;

                return isAdded;
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                return false;
            }
        }

        public async Task<bool> UpdateCustomerAsync(Customer customer)
        {
            try
            {
                var tracking = _databaseContext.Update(customer);

                await _databaseContext.SaveChangesAsync();

                var isModified = tracking.State == EntityState.Modified;

                return isModified;
            }
            catch (Exception e)
            {
                return false;
            }
        }

        public async Task<bool> RemoveCustomerAsync(int id)
        {
            try
            {
                var customer = await _databaseContext.Customers.FindAsync(id);

                var tracking = _databaseContext.Remove(customer);

                await _databaseContext.SaveChangesAsync();

                var isDeleted = tracking.State == EntityState.Deleted;

                return isDeleted;
            }
            catch (Exception e)
            {
                return false;
            }
        }

        public async Task<IEnumerable<Customer>> QueryCustomersAsync(Func<Customer, bool> predicate)
        {
            try
            {
                var customers = _databaseContext.Customers.Where(predicate);

                return customers.ToList();
            }
            catch (Exception e)
            {
                return null;
            }
        }
    }
}