C# select 和 selectmany
WebFeb 22, 2024 · 微信公众号:趣编程ACE关注可了解更多的.NET日常实战开发技巧,如需源码 后台回复 源码 即可;如果觉得对你有帮助,欢迎关注C# Linq中 Select && SelectMany 使用技巧Select 和 SelectMany 是我们开发中对集合常用的两个扩展方法,今天我就用几个小例子并结合源码形式 ... WebAug 4, 2024 · What is the difference between Select and SelectMany in Linq C - Select operator produces one result value for every source SelectMany Operator belong to Projection Operators category. It is used to project each element of a sequence to an IEnumerable and flattens the resulting sequences into one sequence.Exampleclass …
C# select 和 selectmany
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WebNov 1, 2024 · Linq C#中的Select和SelectMany有什么区别? 阅读 56 收藏 0 点赞 0 评论 0 Select运算符为属于投影运算符类别的每个源SelectMany运算符产生一个结果值。WebOct 23, 2024 · SelectManyの使い方. SelectMany の使い方を解説する前に、 SelectMany で何が出来るのかを把握しておきましょう。. SelectMany = 複数のリストをひとつのリストにまとめる. このような考え方で問題ありません。. SelectManyを使用すると指定したリストの複数のリストを一 ...
WebMar 18, 2012 · It is because of the anonymous object in your SelectMany as well as the GroupBy. GroupBy does not return an IEnumerable, but rather IEnumerable> - essentially a collection of collections where each sub collection has the same key value.. In the case you have, grouping by the … 的集合 中 ,记住是原样不动的,不经过处理的,而 select ...
WebMar 3, 2024 · Select() 和 SelectMany() 的工作都是依据源值生成一个或多个结果值。 Select() 为每个源值生成一个结果值。因此,总体结果是一个与源集合具有相同元素数目 … WebExample to Understand LINQ SelectMany Projection Method using C#: Let us understand the LINQ SelectMany Method with an example using C#. In the below example, we are …
WebSelectMany (IEnumerable, Func>, Func) 将序 …
WebJun 13, 2024 · select 的MSDN 解释是 将序列中每一个元素投影到新表中 ;selectMany 将结果投影到IEnumerable cs:go butterfly knife casesWebEl SelectMany (IEnumerable, Func>) método enumera la secuencia de entrada, usa una función de transformación para asignar cada elemento a un IEnumerable y, a continuación, enumera y produce los elementos de cada objeto de este IEnumerable …csgo butterfly knife skin idWebFeb 7, 2024 · SelectMany flattens a returned list of lists, but as you only return a list, there is no need for it (and you can't even use it).. It would come handy, if the Role class would contain a list of UserIds:. public List UserId { get; set; } Then the followind code would help you: positions = positions .Where(x => x.Roles.SelectMany(y => … csgo butterfly knife skinWeb我不明白为什么你在代码中使用SelectMany,你没有列表->你没有得到任何平坦,我的意思是,如果你只使用select,代码中的结果会有什么不同?使用 select ,你会得到一个可 …cs:go butterflyWeb对于一对多关系,在sql server中,我使用以下sql查询 (Status_ID是外键):. 1. 2. 3. SELECT Products .*, Status.Title as Pstatus. FROM Products, Status. WHERE Products.Status_ID = Status.ID. 在MVC中,我使用以下代码来检索与上述sql查询相同的数据,并将列表传递 …csgo butterfly knife pngWebMay 21, 2024 · LINQ Projection Operator SelectMany. In LINQ, projection is an operation which converts an object into the new form which holds only those properties which will be subsequently used. By using projection, a developer can create a new type which is built from each object. You are allowed to project property and conduct … cs:go butterfly knife tWebC# 用于展平的Lambda表达式,c#,C#,我有一个a的集合,其中包含B和C成员 比如说 Class A { } Class B: A { } Class C: A { B children; } 我想要的结果是: collection A -B -B -C -B -B 我需要使用lambda表达式从中提取所有B类型的集合。 ... 如果它是一个集合,请使用SelectMany而不是Select。 ... csgo butterfly knife in real life