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ObservableAsync.CountAsync(IObservableAsync, Func?) method

Defined in

Type: ObservableAsync Namespace: ReactiveUI.Extensions.Async Assembly: ReactiveUI.Extensions.dll

Applies to

net10.0, net10.0-browserwasm1.0, net10.0-desktop1.0, net9.0, net9.0-browserwasm1.0, net9.0-desktop1.0, net8.0, net8.0-ios17.5, net8.0-maccatalyst17.5, net8.0-macos14.2, net8.0-macos14.5, net8.0-tvos17.2, netstandard2.1, net462, net481

Overloads

  • 1. public static ValueTask<int> CountAsync<T>(this IObservableAsync<T> @this, Func<T, bool>? predicate)
  • 2. public static ValueTask<int> CountAsync<T>(this IObservableAsync<T> @this, Func<T, bool>? predicate, CancellationToken cancellationToken)
  • 3. public static ValueTask<int> CountAsync<T>(this IObservableAsync<T> @this)
  • 4. public static ValueTask<int> CountAsync<T>(this IObservableAsync<T> @this, CancellationToken cancellationToken)

1. Overload

public static ValueTask<int> CountAsync<T>(this IObservableAsync<T> @this, Func<T, bool>? predicate)

View source

Summary: Asynchronously counts the number of elements that satisfy a specified condition.

Type parameters

NameDescription
TThe type of elements in the source sequence.

Parameters

NameTypeDescription
this[IObservableAsync](#The source observable sequence.
predicateFunc?A function to test each element for a condition. If null, all elements are counted.

Returns: ValueTask -- A task that represents the asynchronous count operation. The task result contains the number of elements that match the predicate.

2. Overload

public static ValueTask<int> CountAsync<T>(this IObservableAsync<T> @this, Func<T, bool>? predicate, CancellationToken cancellationToken)

Summary: Asynchronously counts the number of elements that satisfy a specified condition.

Type parameters

NameDescription
TThe type of elements in the source sequence.

Parameters

NameTypeDescription
this[IObservableAsync](#The source observable sequence.
predicateFunc?A function to test each element for a condition. If null, all elements are counted.
cancellationTokenCancellationTokenA cancellation token that can be used to cancel the asynchronous operation.

Returns: ValueTask -- A task that represents the asynchronous count operation. The task result contains the number of elements that match the predicate.

3. Overload

public static ValueTask<int> CountAsync<T>(this IObservableAsync<T> @this)

View source

Summary: Asynchronously returns the total number of elements in the data source.

Type parameters

NameDescription
TThe type of elements in the source sequence.

Parameters

NameTypeDescription
this[IObservableAsync](#The source observable sequence.

Returns: ValueTask -- A task that represents the asynchronous operation. The task result contains the number of elements in the data source.

4. Overload

public static ValueTask<int> CountAsync<T>(this IObservableAsync<T> @this, CancellationToken cancellationToken)

View source

Summary: Asynchronously returns the total number of elements in the data source.

Type parameters

NameDescription
TThe type of elements in the source sequence.

Parameters

NameTypeDescription
this[IObservableAsync](#The source observable sequence.
cancellationTokenCancellationTokenA cancellation token that can be used to cancel the asynchronous count operation.

Returns: ValueTask -- A task that represents the asynchronous operation. The task result contains the number of elements in the data source.