DataflowBlock.ReceiveAsync(Of TOutput) Method (ISourceBlock(Of TOutput), CancellationToken)

.NET Framework (current version)

Asynchronously receives a value from a specified source and provides a token to cancel the operation.

Namespace:  System.Threading.Tasks.Dataflow
Assembly:  System.Threading.Tasks.Dataflow (in System.Threading.Tasks.Dataflow.dll)

<ExtensionAttribute> _
Public Shared Function ReceiveAsync(Of TOutput) ( _
	source As ISourceBlock(Of TOutput), _
	cancellationToken As CancellationToken _
) As Task(Of TOutput)

Type Parameters


Specifies the type of data contained in the source.


Type: System.Threading.Tasks.Dataflow.ISourceBlock(Of TOutput)

The source from which to receive the value.

Type: System.Threading.CancellationToken

The token to use to cancel the receive operation.

Return Value

Type: System.Threading.Tasks.Task(Of TOutput)
A task that represents the asynchronous receive operation. When a value is successfully received from the source, the returned task is completed and its Result returns the value. If a value cannot be retrieved because cancellation was requested, the returned task is canceled. If the value cannot be retrieved because the source is empty and completed, an InvalidOperationException exception is thrown in the returned task.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type ISourceBlock(Of TOutput). When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).


source is Nothing.

.NET Framework

Supported in: 4.5

Portable Class Library

Supported in: Portable Class Library