c# - 实现我的数据访问层的接口

Question

我有很多与以下结构相同的类，我想在它们中实现一个接口。那么，是否有人对此有解决方案？

 public static class ClientDAL
      {
        private static string connString = ConfigurationManager.ConnectionStrings["default"].ToString();

    public static ClientEntity NewClient(ClientEntity client)
    {
        using (SqlConnection conn = new SqlConnection())
        {
            conn.ConnectionString = connString;
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = "InsertNewClient";
            cmd.Connection = conn;

            cmd.Parameters.AddWithValue("@ClientID", client.ClientID);
            cmd.Parameters.AddWithValue("@ClientName", client.ClientName);
            cmd.Parameters.AddWithValue("@ClientNif", client.ClientNIF);
            cmd.Parameters.AddWithValue("@ClientAddress", client.ClientAddress);
            cmd.Parameters.AddWithValue("@ClientCountry", client.ClientCountry);
            cmd.Parameters.AddWithValue("@ClientProvincy", client.ClientProvincy);
            cmd.Parameters.AddWithValue("@ClientCity", client.ClientCity);
            cmd.Parameters.AddWithValue("@ClientPhone", client.ClientPhone);
            cmd.Parameters.AddWithValue("@ClientMobile", client.ClientMobile);
            cmd.Parameters.AddWithValue("@ClientFax", client.ClientFax);
            cmd.Parameters.AddWithValue("@ClientEmail", client.ClientEmail);
            cmd.Parameters.AddWithValue("@ClientInfo", client.ClientInfo);
            cmd.ExecuteNonQuery();
        }
        return client;
    }
    /// <summary>
    /// 
    /// </summary>
    /// <param name="clientID"></param>
    /// <returns></returns>
    public static ClientEntity GetClientByID(Int64 clientID)
    {
        ClientEntity client=null;
        using (SqlConnection conn = new SqlConnection())
        {
            conn.ConnectionString = connString;
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = "SelectClient";
            cmd.Connection = conn;

            cmd.Parameters.AddWithValue("@ClientID", clientID);

            SqlDataReader reader = cmd.ExecuteReader();

            while (reader.Read())
            {
                client=LoadClient(reader);
            }
        }
        return client;
    }
    /// <summary>
    /// 
    /// </summary>
    /// <param name="ClientID"></param>
    /// <returns></returns>
    public static bool Exists(Int64 ClientID)
    {
        int numberOfRecord = 0;
        using (SqlConnection conn=new SqlConnection())
        {
            conn.ConnectionString = connString;
            conn.Open();

            SqlCommand cmd = new SqlCommand();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = "SelectValidClient";
            cmd.Connection = conn;
            cmd.Parameters.AddWithValue("@ClientID", ClientID);
            numberOfRecord = Convert.ToInt32(cmd.ExecuteScalar());

        }
        return numberOfRecord > 0;
    }

    public static List<ClientEntity> GetAllClients()
    {
        List<ClientEntity> lista = new List<ClientEntity>();
        using (SqlConnection conn = new SqlConnection())
        {
            conn.ConnectionString = connString;
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = "SelectAllClient";
            cmd.Connection = conn;

            SqlDataReader reader = cmd.ExecuteReader();

            while (reader.Read())
            {
                lista.Add(LoadClient(reader));
            }
        }
        return lista;
    }
    public static ClientEntity UpdateClient(ClientEntity client)
    {
        using (SqlConnection conn = new SqlConnection())
        {
            conn.ConnectionString = connString;
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = "UpdateClient";
            cmd.Connection = conn;

            cmd.Parameters.AddWithValue("@ClientID", client.ClientID);
            cmd.Parameters.AddWithValue("@ClientName", client.ClientName);
            cmd.Parameters.AddWithValue("@ClientNif", client.ClientNIF);
            cmd.Parameters.AddWithValue("@ClientAddress", client.ClientAddress);
            cmd.Parameters.AddWithValue("@ClientCountry", client.ClientCountry);
            cmd.Parameters.AddWithValue("@ClientProvincy", client.ClientProvincy);
            cmd.Parameters.AddWithValue("@ClientCity", client.ClientCity);
            cmd.Parameters.AddWithValue("@ClientPhone", client.ClientPhone);
            cmd.Parameters.AddWithValue("@ClientMobile", client.ClientMobile);
            cmd.Parameters.AddWithValue("@ClientFax", client.ClientFax);
            cmd.Parameters.AddWithValue("@ClientEmail", client.ClientEmail);
            cmd.Parameters.AddWithValue("@ClientInfo", client.ClientInfo);
            cmd.ExecuteNonQuery();
        }
        return client;
    }

    private static ClientEntity LoadClient(IDataReader reader)
    {
        ClientEntity list= new ClientEntity();

        list.ClientID =Convert.ToInt64(reader["ClientID"]);
        list.ClientName = Convert.ToString(reader["ClientName"]);
        list.ClientNIF = Convert.ToInt64(reader["ClientNif"]);
        list.ClientAddress = reader["ClientAddress"]==null?string.Empty:Convert.ToString(reader["ClientAddress"]);
        list.ClientCountry = reader["ClientCountry"]==null?string.Empty:Convert.ToString(reader["ClientCountry"]);
        list.ClientProvincy = reader["ClientProvincy"]==null?string.Empty:Convert.ToString(reader["ClientProvincy"]);
        list.ClientCity = reader["ClientCity"] == null ? string.Empty : Convert.ToString(reader["ClientCity"]);
        list.ClientPhone = reader["ClientPhone"] == null ? string.Empty : Convert.ToString(reader["ClientPhone"]);
        list.ClientMobile = reader["ClientMobile"] == null ? String.Empty : Convert.ToString(reader["ClientMobile"]);
        list.ClientFax = reader["ClientFax"] == null ? String.Empty : Convert.ToString(reader["ClientFax"]);
        list.ClientEmail = reader["ClientEmail"] == null ? string.Empty : Convert.ToString(reader["ClientEmail"]);
        list.ClientInfo = reader["ClientInfo"] == null ? string.Empty : Convert.ToString(reader["ClientInfo"]);

        return list;
}

}

Answer 1

您不能为静态类定义接口。开始重构你的代码，一旦完成，编写一个接口，使用在所有类中重复的相同方法。就像是

public interface IClientDAL
{
    string ConnString { get; set; }

    ClientEntity NewClient(ClientEntity client);
    //...
} 

最后在所有需要它的类中实现接口。