如何才能忽略「空」的條款

Question

我怎麼能忽略name屬性空當排序依據

student.Students= student.student.OrderBy(s=> s.Name ?? null).ToList(); 

上面的代碼總是返回列表list of students having Name = null as 1st element和student with name 'system' in the end.

我想ignore/exclude null in orderby什麼。 n個ull should always come to end of the the list

Answer 1

您可以有條件OrderBy：

student.Students= student.student 
    .OrderBy(s=> s.Name == null ? 1 : 0) 
    .ThenBy(s => s.Name) 
    .ToList(); 

這首先分成兩組，s.Name != null和那些s.Name == null的項目。第二種排序條件是Name本身。