[英]Find object inside collection of List
I have five strong-typed List
objects. 我有五个强类型的
List
对象。 Every object inside every List
have property Rating
and Vote
. 每个
List
每个对象都有属性Rating
和Vote
。
How can I select only 10 top rated object from all List
's objects? 如何从所有
List
对象中仅选择10个最高评级对象? if Rating
equal then need use Vote
如果
Rating
等于那么需要使用Vote
Example(select 2 top rated): 示例(选择2最高评分):
List<Film>
: List<Film>
:
0 element: rating = 1, vote = 2; 1 element: rating = 4, vote = 5;
List<Clubs>
: List<Clubs>
:
0 element: rating = 5, vote = 3; 1 element: rating = 4, vote = 3;
Result: 0 element from Clubs
and 1 element from Film
结果:来自
Clubs
0个元素和来自Film
1个元素
Try something like below 尝试类似下面的内容
var topTen = yourList.OrderBy(x => x.Rating).ThenBy(z => z.Vote).Take(10) var topTen = yourList.OrderBy(x => x.Rating).ThenBy(z => z.Vote).Take(10)
You can start with something like: 您可以从以下内容开始:
var res = l1.Concat(l2).Concat(l3).Concat(l4).Concat(l5)
.OrderByDescending(k => k.Rating)
.ThenBy(k=>k.Vote)
.Take(10).ToList();
where l1...l5 are your lists 其中l1 ... l5是你的清单
If there is no common sub-class among these element types , you can use LINQ to project the lists using a generic Tuple<int, int, object>
(ie rating, vote, and the original element instance) containing the two properties you are interested in. Then you can do a simple query to pick the top 10 elements: 如果这些元素类型中没有公共子类 ,则可以使用LINQ使用包含两个属性的通用
Tuple<int, int, object>
(即rating,vote和原始元素实例)来投影列表。感兴趣。那么你可以做一个简单的查询来选择前10个元素:
List<A> ax = /* ... */;
List<B> bx = /* ... */;
List<C> cx = /* ... */;
/* ... */
IEnumerable<Tuple<int, int, object>> ratingsAndVotes =
ax.Select((a) => Tuple.Create(a.Rating, a.Vote, a)).Concat(
bx.Select((b) => Tuple.Create(b.Rating, b.Vote, b)).Concat(
cx.Select((c) => Tuple.Create(c.Rating, c.Vote, c)) /* ... */;
Tuple<int, int, object>[] topTenItems =
ratingsAndVotes.OrderByDescending((i) => i.Item1).ThenByDescending((i) => i.Item2).Take(10).ToArray();
// topTenItems now contains the top 10 items out of all the lists;
// for each tuple element, Item1 = rating, Item2 = vote,
// Item3 = original list item (as object)
You can use OrderBy and ThenBy to order by two (or more) fields and then use Take to get the top 10: 您可以使用OrderBy和ThenBy按两个(或更多)字段排序,然后使用Take获取前10名:
var myList = new List<Film>();
// ... populate list with some stuff
var top10 = myList.OrderBy(f => f.Rating).ThenBy(f => f.Vote).Take(10);
Hope that helps :) 希望有帮助:)
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