如何才能忽略“空”的条款

Question

我怎么能忽略name属性空当排序依据

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

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

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

Answer 1

您可以有条件OrderBy：

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

这首先分成两组，s.Name != null和那些s.Name == null的项目。第二种排序条件是Name本身。