我寫了一個自定義的LINQ擴展方法,如下所示,但我認爲它可以針對較大的結果進行優化。如何優化此LINQ擴展方法
下面是代碼:
public static IEnumerable<T> OrderByAncesty<T>(this IEnumerable<T> source, Func<T, DateTime> dateSelector, Func<T, float> scoreSelector)
{
var original = source.ToList();
var maxDate = source.Max(dateSelector);
var list = from p in original
let date = dateSelector(p)
let score = scoreSelector(p)
let date1 = date.ToOADate()
let date2 = maxDate.ToOADate()
let ancesty = (1 - (float)date1/(float)date2) * score
select new
{
TObject = p,
Ancesty = ancesty
};
return list.OrderBy(p => p.Ancesty).Select(p => p.TObject);
}
爲什麼你使用表達式而不是'Func'? –
是的,我不知道..我認爲它不是與Func,我要更新我的問題 –