如何使用LINQ来选择对象,最低或最高属性值 [英] How to use LINQ to select object with minimum or maximum property value
问题描述
我有一个可为空DATEOFBIRTH属性Person对象。有没有一种方法使用LINQ查询人的对象列表的之一,最早/最小DATEOFBIRTH值。
这是我开始的:
VAR firstBornDate = People.Min(P => p.DateOfBirth.GetValueOrDefault(DateTime.MaxValue));
空DATEOFBIRTH值,以排除他们闵考虑设置为DateTime.MaxValue(假设至少有一个指定的DOB)。
不过,所有这些都对我来说是设置firstBornDate为datetime值。我想获得的是相匹配的Person对象。我是否需要写第二个查询像这样:
VAR长子= People.Single(P => p.DateOfBirth.GetValueOrDefault(DateTime.MaxValue)== firstBornDate);
还是有这样做的一个更精简的方式?
People.Aggregate((curMin,X)=>(curMin == NULL ||(x.DateOfBirth? ?DateTime.MaxValue)所述; curMin.DateOfBirth×:curMin))
I have a Person object with a Nullable DateOfBirth property. Is there a way to use LINQ to query a list of Person objects for the one with the earliest/smallest DateOfBirth value.
Here's what I started with:
var firstBornDate = People.Min(p => p.DateOfBirth.GetValueOrDefault(DateTime.MaxValue));
Null DateOfBirth values are set to DateTime.MaxValue in order to rule them out of the Min consideration (assuming at least one has a specified DOB).
But all that does for me is to set firstBornDate to a DateTime value. What I'd like to get is the Person object that matches that. Do I need to write a second query like so:
var firstBorn = People.Single(p=>p.DateOfBirth.GetValueOrDefault(DateTime.MaxValue) == firstBornDate);
Or is there a leaner way of doing it?
People.Aggregate((curMin, x) => (curMin == null || (x.DateOfBirth ?? DateTime.MaxValue) < curMin.DateOfBirth ? x : curMin))
这篇关于如何使用LINQ来选择对象,最低或最高属性值的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!