public async Task <ApiResponse> Update(ContactDto contactDto)
 {
     try
     {
         return(new ApiResponse(Status200OK, "Updated Contact", await _contactStore.Update(contactDto)));
     }
     catch (InvalidDataException dataException)
     {
         return(new ApiResponse(Status400BadRequest, "Failed to update Contact"));
     }
 }
        private async Task Save()
        {
            if (String.IsNullOrWhiteSpace(Contact.FirstName) && String.IsNullOrWhiteSpace(Contact.LastName))
            {
                await _pageService.DisplayAlert("Error", "Please enter the name.", "OK");

                return;
            }

            if (Contact.Id == 0)
            {
                await _contactStore.Add(Contact);

                ContactAdded?.Invoke(this, Contact);
            }
            else
            {
                await _contactStore.Update(Contact);

                ContactUpdated?.Invoke(this, Contact);
            }

            await _pageService.PopAsync();
        }
 /// <summary>
 /// Update an existing contact.
 /// </summary>
 /// <param name="id">Contact ID.</param>
 /// <param name="contact">Contact update.</param>
 /// <returns>the updated contact.</returns>
 public Contact Put(int id, Contact contact)
 {
     contact.ContactId = id;
     contactStore.Update(contact);
     return(contact);
 }