Consider ditching Activator.CreateInstance

[dazinator]

You could ditch Activator.CreateInstance for a public default constructor constraint on type T. i.e:

            private IList<T> MapToList<T>(DbDataReader dr) where T: new()
            {
                var objList = new List<T>();
                var props = typeof(T).GetRuntimeProperties();

                var colMapping = dr.GetColumnSchema()
                    .Where(x => props.Any(y => y.Name.ToLower() == x.ColumnName.ToLower()))
                    .ToDictionary(key => key.ColumnName.ToLower());

                if (dr.HasRows)
                {
                    while (dr.Read())
                    {
                        T obj = new T();
                        foreach (var prop in props)
                        {
                            var val = dr.GetValue(colMapping[prop.Name.ToLower()].ColumnOrdinal.Value);
                            prop.SetValue(obj, val == DBNull.Value ? null : val);
                        }
                        objList.Add(obj);
                    }
                }
                return objList;
            }

You could also cache the props for type T, to save calling GetRuntimeProperties on every call you could grab them from the cache if they are there. Not sure how much that would save as I haven't checked to see if GetRuntimeProperties does caching of it's own.

[sp00ky]

Seems like a candidate for a pull request.

[snickler]

I was thinking of something in regards to this. I believe we should switch this to use an Expression Tree instead of reflection. We'll get some great speed improvements out of it. I can look into it over the next few days and see what I can whip up