public List<T> ReadData<T>(string queryString)
{
    using (var connection = new sqlConnection(constr))
        using (var command = new sqlCommand(queryString,connection))
        {
            connection.Open();
            using (var reader = command.ExecuteReader())
                if (reader.HasRows)
                    return Mapper.DynamicMap<IDataReader,List<T>>(reader);
        }
 
    return null;
}

定义你的课程

public class MarkType
{
    public int id { get; set; }
    public string name { get; set; }
    public DateTime inserted { get; set; }
}

使用

List<MarkType> lst = _helper.ReadData<MarkType>("SELECT [id],[name],[inserted] FROM [marktype]");