Почему я получаю ошибку Ошибка Непоследовательная доступность: тип возврата?

Question

Этот проект должен иметь контактный класс и адрес класса и я извлечения информации из файлов данных

namespace Week1.DataAccess 
{ 
    public class AddressBookRepo 
    { 
     private string ConnectionString 
     { 
      get 
      { 
       return ConfigurationManager 
        .ConnectionStrings["AddressbookConnectionString"] 
        .ConnectionString; 
      } 
     } 

     public List<Contact> GetAllContacts() 
     { 
      var contactList = new List<Contact>(); 
      using (var conn = new SqlConnection(ConnectionString)) 
      { 
       using (var command = new SqlCommand()) 
       { 
        command.Connection = conn; 
        command.CommandText = "SELECT * FROM CONTACT"; 
        conn.Open(); 
        using (var reader = command.ExecuteReader()) 
        { 
         while (reader.Read()) 
         { 
          var contact = GetContactFromDataReader(reader); 
          contactList.Add(contact); 
         } 
        } 
       } 

      } 

      return contactList; 
     } 

     public Contact GetContactById(int id) 
     { 
      Contact contact = null; 

      using (var conn = new SqlConnection(ConnectionString)) 
      { 
       using (var command = new SqlCommand()) 
       { 
        command.Connection = conn; 
        conn.Open(); 
        command.CommandText = 
           @"SELECT * 
           FROM CONTACT 
           WHERE ContactID = @ContactId"; 
        command.Parameters.AddWithValue("ContactID", id); 

        using (var reader = command.ExecuteReader()) 
        { 
         reader.Read(); 
         contact = GetContactFromDataReader(reader); 
        } 
       } 
      } 
      return contact; 
     } 

     // 2.) create a GetAllAddresses method 
     public List<Address> GetAllAddresses() //i am getting error here 
     { 
      var addressList = new List<Address>(); 
      using (var conn = new SqlConnection(ConnectionString)) 
      { 
       using (var command = new SqlCommand()) 
       { 
        command.Connection = conn; 
        command.CommandText = "SELECT * FROM ADDRESS"; 
        conn.Open(); 
        using (var reader = command.ExecuteReader()) 
        { 
         while (reader.Read()) 
         { 
          var address = GetAddressFromDataReader(reader); 
          addressList.Add(address); 
         } 
        } 
       } 

      } 

      return addressList; 
     } 

     // 3.) create a GetAddressById method 
     public Address GetAddressById(int id)// I am getting error here 
     { 
      Address address = null; 

      using (var conn = new SqlConnection(ConnectionString)) 
      { 
       using (var command = new SqlCommand()) 
       { 
        command.Connection = conn; 
        conn.Open(); 
        command.CommandText = 
           @"SELECT * 
           FROM ADDRESS 
           WHERE ADDRESSID = @AddressId"; 
        command.Parameters.AddWithValue("addressID", id); 

        using (var reader = command.ExecuteReader()) 
        { 
         reader.Read(); 
         address = GetAddressFromDataReader(reader); 
        } 
       } 
      } 
      return address; 
     } 


     // 4.) create a method to GetAddressesByState (extra credit) 

     private static Contact GetContactFromDataReader(SqlDataReader reader) 
     { 
      var contact = new Contact 
      { 
       ContactId = Convert.ToInt32(reader["ContactID"]), 
       FirstName = Convert.ToString(reader["FirstName"]).Trim(), 
       LastName = Convert.ToString(reader["LastName"]).Trim(), 
       Title = reader["Title"].ToString().Trim(), 
       AddDate = (DateTime)reader["AddDate"], 
       ModifiedDate = (DateTime)reader["ModifiedDate"] 
      }; 
      return contact; 
     } 

     private static Address GetAddressFromDataReader(SqlDataReader reader) 
     { 
      var address = new Address 
      { 
       AddressId = Convert.ToInt32(reader["addressID"]), 
       Street1 = Convert.ToString(reader["Street1"]), 
       Street2 = Convert.ToString(reader["Street2"]), 
       City = Convert.ToString(reader["City"]), 
       StateProvince = Convert.ToString(reader["StateProvince"]), 
       CountryRegion = Convert.ToString(reader["CountryRegion"]), 
       PostalCode = Convert.ToString(reader["PostalCode"]), 
       AddressType = Convert.ToString(reader["AddressType"]), 
       ContactId = Convert.ToInt32(reader["ContactID"]), 
       ModifiedDate = (DateTime)reader["ModifiedDate"] 
      }; 
      return address; 
     } 
    } 
} 

Answer 1

Ваши классы (вероятно Адрес объявления/или контакт), вероятно, не публичный, чтобы соответствовать acessibility из методы, которые они используются в