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AsyncEnumerable.SingleAsync Method

Definition

Overloads

SingleAsync<TSource>(IAsyncEnumerable<TSource>, CancellationToken)

Returns the only element of a sequence, and throws an exception if there is not exactly one element in the sequence.

SingleAsync<TSource>(IAsyncEnumerable<TSource>, Func<TSource,Boolean>, CancellationToken)

Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

SingleAsync<TSource>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<Boolean>>, CancellationToken)

Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

SingleAsync<TSource>(IAsyncEnumerable<TSource>, CancellationToken)

Source:
SingleAsync.cs

Returns the only element of a sequence, and throws an exception if there is not exactly one element in the sequence.

C#
public static System.Threading.Tasks.ValueTask<TSource> SingleAsync<TSource>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, System.Threading.CancellationToken cancellationToken = default);

Type Parameters

TSource

The type of the elements of source.

Parameters

source
IAsyncEnumerable<TSource>

An IAsyncEnumerable<T> to return the single element of.

cancellationToken
CancellationToken

The CancellationToken to monitor for cancellation requests. The default is None.

Returns

ValueTask<TSource>

The single element of the input sequence.

Exceptions

source is null.

The source sequence contains more than one element. (via the returned task).

Applies to

.NET 10 és más verziók
Termék Verziók
.NET 8 (package-provided), 9 (package-provided), 10 (package-provided), 10
.NET Standard 2.0 (package-provided)

SingleAsync<TSource>(IAsyncEnumerable<TSource>, Func<TSource,Boolean>, CancellationToken)

Source:
SingleAsync.cs

Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

C#
public static System.Threading.Tasks.ValueTask<TSource> SingleAsync<TSource>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,bool> predicate, System.Threading.CancellationToken cancellationToken = default);

Type Parameters

TSource

The type of the elements of source.

Parameters

source
IAsyncEnumerable<TSource>

An IAsyncEnumerable<T> to return the single element of.

predicate
Func<TSource,Boolean>

A function to test an element for a condition.

cancellationToken
CancellationToken

The CancellationToken to monitor for cancellation requests. The default is None.

Returns

ValueTask<TSource>

The single element of the input sequence that satisfies a condition.

Exceptions

predicate is null.

More than one element satisfies the condition in predicate (via the returned task).

Applies to

.NET 10 és más verziók
Termék Verziók
.NET 8 (package-provided), 9 (package-provided), 10 (package-provided), 10
.NET Standard 2.0 (package-provided)

SingleAsync<TSource>(IAsyncEnumerable<TSource>, Func<TSource,CancellationToken,ValueTask<Boolean>>, CancellationToken)

Source:
SingleAsync.cs

Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

C#
public static System.Threading.Tasks.ValueTask<TSource> SingleAsync<TSource>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Func<TSource,System.Threading.CancellationToken,System.Threading.Tasks.ValueTask<bool>> predicate, System.Threading.CancellationToken cancellationToken = default);

Type Parameters

TSource

The type of the elements of source.

Parameters

source
IAsyncEnumerable<TSource>

An IAsyncEnumerable<T> to return the single element of.

predicate
Func<TSource,CancellationToken,ValueTask<Boolean>>

A function to test an element for a condition.

cancellationToken
CancellationToken

The CancellationToken to monitor for cancellation requests. The default is None.

Returns

ValueTask<TSource>

The single element of the input sequence that satisfies a condition.

Exceptions

predicate is null.

More than one element satisfies the condition in predicate (via the returned task).

Applies to

.NET 10 és más verziók
Termék Verziók
.NET 8 (package-provided), 9 (package-provided), 10 (package-provided), 10
.NET Standard 2.0 (package-provided)