泛型方法

 static TEntity MapEntity<TEntity>(SqlDataReader reader) where TEntity : class ,new()
        {
            var pros = typeof(TEntity).GetProperties();
            var entity = new TEntity();
            foreach (var item in pros)
            {
                var index = reader.GetOrdinal(item.Name);
                var data = reader.GetValue(index);
                item.SetValue(entity, Convert.ChangeType(data, item.PropertyType),null);
            }
            return entity;
        }