AsyncEnumerable.MaxByAsync Method
Definition
Important
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Overloads
| MaxByAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>, CancellationToken) |
Returns the maximum value in a generic sequence according to a specified key selector function. |
| MaxByAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<TKey>>, IComparer<TKey>, CancellationToken) |
Returns the maximum value in a generic sequence according to a specified key selector function. |
MaxByAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>, CancellationToken)
- Source:
- MaxByAsync.cs
Returns the maximum value in a generic sequence according to a specified key selector function.
public static System.Threading.Tasks.ValueTask<TSource?> MaxByAsync<TSource,TKey>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,TKey> keySelector, System.Collections.Generic.IComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);static member MaxByAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, 'Key> * System.Collections.Generic.IComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<'Source><Extension()>
Public Function MaxByAsync(Of TSource, TKey) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), Optional comparer As IComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of TSource)Type Parameters
- TSource
The type of the elements of source.
- TKey
The type of key to compare elements by.
Parameters
- source
- IAsyncEnumerable<TSource>
A sequence of values to determine the maximum value of.
- keySelector
- Func<TSource,TKey>
A function to extract the key for each element.
- comparer
- IComparer<TKey>
The IComparer<T> to compare keys.
- cancellationToken
- CancellationToken
The CancellationToken to monitor for cancellation requests. The default is None.
Returns
The value with the maximum key in the sequence.
Exceptions
source is null.
No key extracted from source implements the IComparable or IComparable<T> interface.
Remarks
If TKey is a reference type and the source sequence is empty or contains only values that are null, this method returns null.
Applies to
MaxByAsync<TSource,TKey>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<TKey>>, IComparer<TKey>, CancellationToken)
- Source:
- MaxByAsync.cs
Returns the maximum value in a generic sequence according to a specified key selector function.
public static System.Threading.Tasks.ValueTask<TSource?> MaxByAsync<TSource,TKey>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,System.Threading.CancellationToken,System.Threading.Tasks.ValueTask<TKey>> keySelector, System.Collections.Generic.IComparer<TKey>? comparer = default, System.Threading.CancellationToken cancellationToken = default);static member MaxByAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Func<'Source, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<'Key>> * System.Collections.Generic.IComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<'Source><Extension()>
Public Function MaxByAsync(Of TSource, TKey) (source As IAsyncEnumerable(Of TSource), keySelector As Func(Of TSource, CancellationToken, ValueTask(Of TKey)), Optional comparer As IComparer(Of TKey) = Nothing, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of TSource)Type Parameters
- TSource
The type of the elements of source.
- TKey
The type of key to compare elements by.
Parameters
- source
- IAsyncEnumerable<TSource>
A sequence of values to determine the maximum value of.
- keySelector
- Func<TSource,CancellationToken,ValueTask<TKey>>
A function to extract the key for each element.
- comparer
- IComparer<TKey>
The IComparer<T> to compare keys.
- cancellationToken
- CancellationToken
The CancellationToken to monitor for cancellation requests. The default is None.
Returns
The value with the maximum key in the sequence.
Exceptions
source is null.
No key extracted from source implements the IComparable or IComparable<T> interface.
Remarks
If TKey is a reference type and the source sequence is empty or contains only values that are null, this method returns null.
