ActionBlock<TInput> 类

定义

命名空间:

System.Threading.Tasks.Dataflow

程序集:

System.Threading.Tasks.Dataflow.dll

程序包:

System.Threading.Tasks.Dataflow v11.0.0-rc.1.26425.128

Source:

ActionBlock.cs

提供一个数据流块，该块为收到的每个数据元素调用提供的 Action<T> 委托。

generic <typename TInput>
public ref class ActionBlock sealed : System::Threading::Tasks::Dataflow::ITargetBlock<TInput>

public sealed class ActionBlock<TInput> : System.Threading.Tasks.Dataflow.ITargetBlock<TInput>

type ActionBlock<'Input> = class
    interface ITargetBlock<'Input>
    interface IDataflowBlock

Public NotInheritable Class ActionBlock(Of TInput)
Implements ITargetBlock(Of TInput)

类型参数

TInput

此操作 ActionBlock<TInput> 所依据的数据类型。

继承

Object

ActionBlock<TInput>

实现

IDataflowBlock ITargetBlock<TInput>

示例

下面的示例演示如何使用 ActionBlock<TInput> 类使用数据流块执行多个计算，并返回执行计算所需的已用时间。 此代码示例是为 如何：在数据流块文章中指定并行度的大型示例的一 部分。

// Performs several computations by using dataflow and returns the elapsed
// time required to perform the computations.
static TimeSpan TimeDataflowComputations(int maxDegreeOfParallelism,
   int messageCount)
{
   // Create an ActionBlock<int> that performs some work.
   var workerBlock = new ActionBlock<int>(
      // Simulate work by suspending the current thread.
      millisecondsTimeout => Thread.Sleep(millisecondsTimeout),
      // Specify a maximum degree of parallelism.
      new ExecutionDataflowBlockOptions
      {
         MaxDegreeOfParallelism = maxDegreeOfParallelism
      });

   // Compute the time that it takes for several messages to
   // flow through the dataflow block.

   Stopwatch stopwatch = new Stopwatch();
   stopwatch.Start();

   for (int i = 0; i < messageCount; i++)
   {
      workerBlock.Post(1000);
   }
   workerBlock.Complete();

   // Wait for all messages to propagate through the network.
   workerBlock.Completion.Wait();

   // Stop the timer and return the elapsed number of milliseconds.
   stopwatch.Stop();
   return stopwatch.Elapsed;
}

' Demonstrates how to specify the maximum degree of parallelism 
' when using dataflow.
Friend Class Program
   ' Performs several computations by using dataflow and returns the elapsed
   ' time required to perform the computations.
   Private Shared Function TimeDataflowComputations(ByVal maxDegreeOfParallelism As Integer, ByVal messageCount As Integer) As TimeSpan
      ' Create an ActionBlock<int> that performs some work.
      Dim workerBlock = New ActionBlock(Of Integer)(Function(millisecondsTimeout) Pause(millisecondsTimeout), New ExecutionDataflowBlockOptions() With { .MaxDegreeOfParallelism = maxDegreeOfParallelism})
         ' Simulate work by suspending the current thread.
         ' Specify a maximum degree of parallelism.

      ' Compute the time that it takes for several messages to 
      ' flow through the dataflow block.

      Dim stopwatch As New Stopwatch()
      stopwatch.Start()

      For i As Integer = 0 To messageCount - 1
         workerBlock.Post(1000)
      Next i
      workerBlock.Complete()

      ' Wait for all messages to propagate through the network.
      workerBlock.Completion.Wait()

      ' Stop the timer and return the elapsed number of milliseconds.
      stopwatch.Stop()
      Return stopwatch.Elapsed
   End Function

   Private Shared Function Pause(ByVal obj As Object)
      Thread.Sleep(obj)
      Return Nothing
   End Function

构造函数

名称	说明
ActionBlock<TInput>(Action<TInput>, ExecutionDataflowBlockOptions)	使用指定的操作和配置选项初始化类的新实例 ActionBlock<TInput> 。
ActionBlock<TInput>(Action<TInput>)	使用指定的操作初始化类的新实例 ActionBlock<TInput> 。
ActionBlock<TInput>(Func<TInput,Task>, ExecutionDataflowBlockOptions)	使用指定的操作和配置选项初始化类的新实例 ActionBlock<TInput> 。
ActionBlock<TInput>(Func<TInput,Task>)	使用指定的操作初始化类的新实例 ActionBlock<TInput> 。

属性

名称	说明
Completion	获取一个 Task 对象，该对象表示数据流块的异步操作和完成。
InputCount	获取等待此块处理的输入项数。

方法

名称	说明
Complete()	向数据流块发出信号，表示它不应接受或生成更多消息，并且不应再使用任何推迟的消息。
Post(TInput)	将项发布到目标数据流块。
ToString()	返回一个字符串，表示此 IDataflowBlock 实例的格式名称。

显式接口实现

名称	说明
IDataflowBlock.Fault(Exception)	导致数据流块处于错误状态完成。
ITargetBlock<TInput>.OfferMessage(DataflowMessageHeader, TInput, ISourceBlock<TInput>, Boolean)	向数据流块提供消息，并有机会使用或推迟消息。

扩展方法

名称	说明
AsObserver<TInput>(ITargetBlock<TInput>)	创建一个新的IObserver<T>抽象。ITargetBlock<TInput>
Post<TInput>(ITargetBlock<TInput>, TInput)	将项目发布到 .ITargetBlock<TInput>
SendAsync<TInput>(ITargetBlock<TInput>, TInput, CancellationToken)	以异步方式向目标消息块提供消息，从而允许推迟。
SendAsync<TInput>(ITargetBlock<TInput>, TInput)	以异步方式向目标消息块提供消息，从而允许推迟。