DataflowBlock.ReceiveAsync<TOutput> Method (ISourceBlock<TOutput>)

.NET Framework (current version)

Asynchronously receives a value from a specified source.

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

public static Task<TOutput> ReceiveAsync<TOutput>(
	this ISourceBlock<TOutput> source

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.

Return Value

Type: System.Threading.Tasks.Task<TOutput>
A task that represents the asynchronous receive operation. When an item value is successfully received from the source, the returned task is completed and its Result returns the received value. If an item 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<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 null.

.NET Framework

Supported in: 4.5

Portable Class Library

Supported in: Portable Class Library