AsyncEnumerable.ToLookupAsync Method
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ToLookupAsync<TSource,TKey,TElement>(IAsyncEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>, CancellationToken)
- Source:
- ToLookupAsync.cs
Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function and element selector functions.
public static System.Threading.Tasks.ValueTask<System.Linq.ILookup<TKey,TElement>> ToLookupAsync<TSource,TKey,TElement>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,TKey> keySelector, Func<TSource,TElement> elementSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);static member ToLookupAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, 'Key> * Func<'Source, 'Element> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<System.Linq.ILookup<'Key, 'Element>><Extension()>
Public Function ToLookupAsync(Of TSource, TKey, TElement) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), elementSelector As Func(Of TSource, TElement), Optional comparer As IEqualityComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of ILookup(Of TKey, TElement))Type Parameters
- TSource
The type of the elements of source.
- TKey
The type of the key returned by keySelector.
- TElement
The type of the value returned by elementSelector.
Parameters
- source
- IAsyncEnumerable<TSource>
The IAsyncEnumerable<T> to create a ILookup<TKey,TElement> from.
- keySelector
- Func<TSource,TKey>
A function to extract a key from each element.
- elementSelector
- Func<TSource,TElement>
A transform function to produce a result element value from each element.
- comparer
- IEqualityComparer<TKey>
An IEqualityComparer<T> to compare keys.
- cancellationToken
- CancellationToken
The CancellationToken to monitor for cancellation requests. The default is None.
Returns
A ILookup<TKey,TElement> that contains keys and values.
Exceptions
keySelector is null.
Applies to
.NET 10 та інші версії
| Продукт | Версії |
|---|---|
| .NET | 8 (package-provided), 9 (package-provided), 10 (package-provided), 10 |
| .NET Standard | 2.0 (package-provided) |
ToLookupAsync<TSource,TKey,TElement>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<TKey>>, Func<TSource, CancellationToken,ValueTask<TElement>>, IEqualityComparer<TKey>, CancellationToken)
- Source:
- ToLookupAsync.cs
Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function and element selector functions.
public static System.Threading.Tasks.ValueTask<System.Linq.ILookup<TKey,TElement>> ToLookupAsync<TSource,TKey,TElement>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,System.Threading.CancellationToken,System.Threading.Tasks.ValueTask<TKey>> keySelector, Func<TSource,System.Threading.CancellationToken,System.Threading.Tasks.ValueTask<TElement>> elementSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);static member ToLookupAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<'Key>> * Func<'Source, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<'Element>> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<System.Linq.ILookup<'Key, 'Element>><Extension()>
Public Function ToLookupAsync(Of TSource, TKey, TElement) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, CancellationToken, ValueTask(Of TKey)), elementSelector As Func(Of TSource, CancellationToken, ValueTask(Of TElement)), Optional comparer As IEqualityComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of ILookup(Of TKey, TElement))Type Parameters
- TSource
The type of the elements of source.
- TKey
The type of the key returned by keySelector.
- TElement
The type of the value returned by elementSelector.
Parameters
- source
- IAsyncEnumerable<TSource>
The IAsyncEnumerable<T> to create a ILookup<TKey,TElement> from.
- keySelector
- Func<TSource,CancellationToken,ValueTask<TKey>>
A function to extract a key from each element.
- elementSelector
- Func<TSource,CancellationToken,ValueTask<TElement>>
A transform function to produce a result element value from each element.
- comparer
- IEqualityComparer<TKey>
An IEqualityComparer<T> to compare keys.
- cancellationToken
- CancellationToken
The CancellationToken to monitor for cancellation requests. The default is None.
Returns
A ILookup<TKey,TElement> that contains keys and values.
Exceptions
keySelector is null.
Applies to
.NET 10 та інші версії
| Продукт | Версії |
|---|---|
| .NET | 8 (package-provided), 9 (package-provided), 10 (package-provided), 10 |
| .NET Standard | 2.0 (package-provided) |
ToLookupAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<TKey>>, IEqualityComparer<TKey>, CancellationToken)
- Source:
- ToLookupAsync.cs
Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function.
public static System.Threading.Tasks.ValueTask<System.Linq.ILookup<TKey,TSource>> ToLookupAsync<TSource,TKey>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,System.Threading.CancellationToken,System.Threading.Tasks.ValueTask<TKey>> keySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);static member ToLookupAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<'Key>> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<System.Linq.ILookup<'Key, 'Source>><Extension()>
Public Function ToLookupAsync(Of TSource, TKey) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, CancellationToken, ValueTask(Of TKey)), Optional comparer As IEqualityComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of ILookup(Of TKey, TSource))Type Parameters
- TSource
The type of the elements of source.
- TKey
The type of the key returned by keySelector.
Parameters
- source
- IAsyncEnumerable<TSource>
The IAsyncEnumerable<T> to create a ILookup<TKey,TElement> from.
- keySelector
- Func<TSource,CancellationToken,ValueTask<TKey>>
A function to extract a key from each element.
- comparer
- IEqualityComparer<TKey>
An IEqualityComparer<T> to compare keys.
- cancellationToken
- CancellationToken
The CancellationToken to monitor for cancellation requests. The default is None.
Returns
A ILookup<TKey,TElement> that contains keys and values.
Exceptions
keySelector is null.
Applies to
.NET 10 та інші версії
| Продукт | Версії |
|---|---|
| .NET | 8 (package-provided), 9 (package-provided), 10 (package-provided), 10 |
| .NET Standard | 2.0 (package-provided) |
ToLookupAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>, CancellationToken)
- Source:
- ToLookupAsync.cs
Creates a ILookup<TKey,TElement> from an IAsyncEnumerable<T> according to a specified key selector function.
public static System.Threading.Tasks.ValueTask<System.Linq.ILookup<TKey,TSource>> ToLookupAsync<TSource,TKey>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,TKey> keySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);static member ToLookupAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, 'Key> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<System.Linq.ILookup<'Key, 'Source>><Extension()>
Public Function ToLookupAsync(Of TSource, TKey) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), Optional comparer As IEqualityComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of ILookup(Of TKey, TSource))Type Parameters
- TSource
The type of the elements of source.
- TKey
The type of the key returned by keySelector.
Parameters
- source
- IAsyncEnumerable<TSource>
The IAsyncEnumerable<T> to create a ILookup<TKey,TElement> from.
- keySelector
- Func<TSource,TKey>
A function to extract a key from each element.
- comparer
- IEqualityComparer<TKey>
An IEqualityComparer<T> to compare keys.
- cancellationToken
- CancellationToken
The CancellationToken to monitor for cancellation requests. The default is None.
Returns
A ILookup<TKey,TElement> that contains keys and values.
Exceptions
keySelector is null.
Applies to
.NET 10 та інші версії
| Продукт | Версії |
|---|---|
| .NET | 8 (package-provided), 9 (package-provided), 10 (package-provided), 10 |
| .NET Standard | 2.0 (package-provided) |
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