Enumerable.CountBy<TSource,TKey> 方法

定义

命名空间:

System.Linq

程序集:

System.Linq.dll

Source:

CountBy.cs

public static System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,int>> CountBy<TSource,TKey> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,TKey> keySelector, System.Collections.Generic.IEqualityComparer<TKey>? keyComparer = default);

static member CountBy : seq<'Source> * Func<'Source, 'Key> * System.Collections.Generic.IEqualityComparer<'Key> -> seq<System.Collections.Generic.KeyValuePair<'Key, int>>

<Extension()>
Public Function CountBy(Of TSource, TKey) (source As IEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), Optional keyComparer As IEqualityComparer(Of TKey) = Nothing) As IEnumerable(Of KeyValuePair(Of TKey, Integer))

类型参数

TSource

TKey

参数

source

IEnumerable<TSource>

keySelector

Func<TSource,TKey>

keyComparer

IEqualityComparer<TKey>

返回

IEnumerable<KeyValuePair<TKey,Int32>>