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ISourceBlock(TOutput).ConsumeMessage Method

TransformManyBlock<TInput, TOutput>.ISourceBlock<TOutput>.ConsumeMessage Method

.NET Framework 4.6 and 4.5

Called by a linked ITargetBlock<TInput> to accept and consume a DataflowMessageHeader previously offered by this ISourceBlock<TOutput>.

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

TOutput ISourceBlock<TOutput>.ConsumeMessage(
	DataflowMessageHeader messageHeader,
	ITargetBlock<TOutput> target,
	out bool messageConsumed


Type: System.Threading.Tasks.Dataflow.DataflowMessageHeader

The DataflowMessageHeader of the message being consumed.

Type: System.Threading.Tasks.Dataflow.ITargetBlock<TOutput>

The ITargetBlock<TInput> consuming the message.

Type: System.Boolean

true if the message was successfully consumed; otherwise, false.

Return Value

Type: TOutput
The value of the consumed message. This may correspond to a different DataflowMessageHeader instance than was previously reserved and passed as the messageHeader to ConsumeMessage. The consuming ITargetBlock<TInput> must use the returned value instead of the value passed as messageValue through OfferMessage ITargetBlock<TInput>.OfferMessage
If the message requested is not available, the return value will be null.


ISourceBlock<TOutput>.ConsumeMessage(DataflowMessageHeader, ITargetBlock<TOutput>, Boolean)


The messageHeader is not valid.


The target is null.

Only ITargetBlock<TInput> instances linked to this ISourceBlock<TOutput> instance may use ConsumeMessage, and it must only be used to consume DataflowMessageHeader instances previously offered by this source to the target.

.NET Framework

Supported in: 4.5

Portable Class Library

Supported in: Portable Class Library
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