EntityFrameworkQueryableExtensions.ContainsAsync<TSource> Method

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Asynchronously determines whether a sequence contains a specified element by using the default equality comparer.

public static System.Threading.Tasks.Task<bool> ContainsAsync<TSource> (this System.Linq.IQueryable<TSource> source, TSource item, System.Threading.CancellationToken cancellationToken = default);

static member ContainsAsync : System.Linq.IQueryable<'Source> * 'Source * System.Threading.CancellationToken -> System.Threading.Tasks.Task<bool>

<Extension()>
Public Function ContainsAsync(Of TSource) (source As IQueryable(Of TSource), item As TSource, Optional cancellationToken As CancellationToken = Nothing) As Task(Of Boolean)

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IQueryable<TSource>

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

item: TSource

The object to locate in the sequence.

cancellationToken: CancellationToken

A CancellationToken to observe while waiting for the task to complete.

Returns

Task<Boolean>

A task that represents the asynchronous operation. The task result contains true if the input sequence contains the specified value; otherwise, false.

Exceptions

ArgumentNullException

source is null.

OperationCanceledException

If the CancellationToken is canceled.

Remarks

Multiple active operations on the same context instance are not supported. Use await to ensure that any asynchronous operations have completed before calling another method on this context. See Avoiding DbContext threading issues for more information and examples.

See Querying data with EF Core for more information and examples.

Applies to

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