DataflowBlock.Receive(TOutput) Method (ISourceBlock(TOutput), CancellationToken)

.NET Framework (current version)

Synchronously 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)

static member Receive : 
        source:ISourceBlock<'TOutput> * 
        cancellationToken:CancellationToken -> 'TOutput 

Type Parameters


The type of data contained in the source.


Type: System.Threading.Tasks.Dataflow.ISourceBlock(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: TOutput
The received value.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type ISourceBlock(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 a null reference (Nothing in Visual Basic).


No item could be received from the source.


The operation was canceled before an item was received from the source.

If the source successfully offered an item that was received by this operation, that item is returned even if a concurrent cancellation request occurs.

.NET Framework

Supported in: 4.5

Portable Class Library

Supported in: Portable Class Library