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AsyncEnumerable.ToLookup<TSource, TKey, TElement> Method (IAsyncEnumerable<TSource>, Func<TSource, TKey>, Func<TSource, TElement>)

Namespace: System.Linq
Assembly: System.Interactive.Async (in System.Interactive.Async.dll) Version: 1.2.0.0
Syntax
C#
Copy
public static Task<ILookup<TKey, TElement>> ToLookup<TSource, TKey, TElement>(
	this IAsyncEnumerable<TSource> source,
	Func<TSource, TKey> keySelector,
	Func<TSource, TElement> elementSelector
)

Parameters

source
Type: System.Collections.Generic.IAsyncEnumerable<TSource>
keySelector
Type: System.Func<TSource, TKey>
elementSelector
Type: System.Func<TSource, TElement>

Type Parameters

TSource
TKey
TElement

Return Value

Type: Task<ILookup<TKey, TElement>>

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IAsyncEnumerable<TSource>. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).
See Also