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

Definition

Namespace:

System.Threading.Tasks.Dataflow

Assembly:

System.Threading.Tasks.Dataflow.dll

Package:

System.Threading.Tasks.Dataflow v9.0.0-rc.2.24473.5

Source:

TransformBlock.cs

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

 virtual TOutput System.Threading.Tasks.Dataflow.ISourceBlock<TOutput>.ConsumeMessage(System::Threading::Tasks::Dataflow::DataflowMessageHeader messageHeader, System::Threading::Tasks::Dataflow::ITargetBlock<TOutput> ^ target, [Runtime::InteropServices::Out] bool % messageConsumed) = System::Threading::Tasks::Dataflow::ISourceBlock<TOutput>::ConsumeMessage;

TOutput ISourceBlock<TOutput>.ConsumeMessage (System.Threading.Tasks.Dataflow.DataflowMessageHeader messageHeader, System.Threading.Tasks.Dataflow.ITargetBlock<TOutput> target, out bool messageConsumed);

abstract member System.Threading.Tasks.Dataflow.ISourceBlock<TOutput>.ConsumeMessage : System.Threading.Tasks.Dataflow.DataflowMessageHeader * System.Threading.Tasks.Dataflow.ITargetBlock<'Output> * bool -> 'Output
override this.System.Threading.Tasks.Dataflow.ISourceBlock<TOutput>.ConsumeMessage : System.Threading.Tasks.Dataflow.DataflowMessageHeader * System.Threading.Tasks.Dataflow.ITargetBlock<'Output> * bool -> 'Output

Function ConsumeMessage (messageHeader As DataflowMessageHeader, target As ITargetBlock(Of TOutput), ByRef messageConsumed As Boolean) As TOutput Implements ISourceBlock(Of TOutput).ConsumeMessage

Parameters

messageHeader

DataflowMessageHeader

The DataflowMessageHeader of the message being consumed.

target

ITargetBlock<TOutput>

The ITargetBlock<TInput> consuming the message.

messageConsumed

Boolean

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

Returns

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(DataflowMessageHeader, ITargetBlock<TOutput>, Boolean). The consuming ITargetBlock<TInput> must use the returned value instead of the value passed as messageValue through ITargetBlock<TInput>.OfferMessage(DataflowMessageHeader, TInput, ISourceBlock<TInput>, Boolean).

If the message requested is not available, the return value will be null.

Implements

ConsumeMessage(DataflowMessageHeader, ITargetBlock<TOutput>, Boolean)

Exceptions

ArgumentException

The messageHeader is not valid.

ArgumentNullException

The target is null.

Remarks

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.