Observable.ToObservable < TSource 方法 (IEnumerable < TSource >> 、IScheduler)

發行項
06/28/2011

使用指定的來源和排程器，將可列舉序列轉換為可觀察的序列。

Namespace：System.Reactive.Linq
裝配： System.Reactive.dll) 中的 System.Reactive (

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function ToObservable(Of TSource) ( _
    source As IEnumerable(Of TSource), _
    scheduler As IScheduler _
) As IObservable(Of TSource)

'Usage
Dim source As IEnumerable(Of TSource)
Dim scheduler As IScheduler
Dim returnValue As IObservable(Of TSource)

returnValue = source.ToObservable(scheduler)

public static IObservable<TSource> ToObservable<TSource>(
    this IEnumerable<TSource> source,
    IScheduler scheduler
)

[ExtensionAttribute]
public:
generic<typename TSource>
static IObservable<TSource>^ ToObservable(
    IEnumerable<TSource>^ source, 
    IScheduler^ scheduler
)

static member ToObservable : 
        source:IEnumerable<'TSource> * 
        scheduler:IScheduler -> IObservable<'TSource>

JScript does not support generic types and methods.

類型參數

TSource
來源的類型。

參數

source
類型：System.Collections.Generic.IEnumerable< TSource>
要轉換成可觀察序列的可列舉序列。

scheduler
類型： System.Reactive.Concurrency.IScheduler
要執行輸入序列列舉的排程器。

傳回值

類型：System.IObservable< TSource>
可觀察的序列，其專案是從指定的可列舉序列提取。

使用注意事項

在 Visual Basic 和 C# 中，您可以在IEnumerable< TSource > 類型的任何物件上呼叫此方法作為實例方法。使用執行個體方法語法呼叫這個方法時，請省略第一個參數。如需詳細資訊，請參閱或。

備註

ToObservable 運算子會從支援 IEnumerable 介面的物件建立可觀察的序列。此運算子會提供排程器參數，以允許建立可觀察序列所需的處理不同排程選項。例如，您可能想要排程在另一個執行緒上發生的列舉處理。

範例

這個範例會從 System.IO 傳回之字串陣列所公開的 IEnumerable) 字串，建立 (IObservable << 字串 > 的可觀察字串 > 序列。 Directory.GetDirectories 方法。 ThreadPoolScheduler排程器會針對排程器參數傳遞至 ToObservable 運算子。這會導致列舉在 .NET 執行緒集區的執行緒上執行。因此不會封鎖主執行緒。

using System;
using System.IO;
using System.Reactive.Linq;
using System.Reactive.Concurrency;

namespace Example
{
  class Program
  {
    static void Main()
    {
      //*********************************************************************************************************************//
      //*** Create a new observable sequence from the IEnumerable<String> exposed by the string array returned from       ***//
      //*** System.IO.Directory.GetDirectories().                                                                         ***//
      //***                                                                                                               ***//
      //*** In this example we use the ThreadPool scheduler to run the enumeration on a thread in the .NET thread pool.   ***//
      //*** This way our main thread is not blocked by the enumeration and we can process user interaction.               ***//
      //*********************************************************************************************************************//

      var fileList = Directory.GetDirectories(@"C:\Program Files");
      var seqfiles = fileList.ToObservable(Scheduler.ThreadPool);


      //*********************************************************************************************************************//
      //*** We subscribe to this sequence with a lambda expression as the action event handler for the OnNext action. It  ***//
      //*** writes each filename to the console window. A action event handler for the OnCompleted action is also         ***//
      //*** provided to inform the user the sequence has ended and prompt for the ENTER key.                              ***//
      //*********************************************************************************************************************//

      Console.WriteLine("\nCreating subscription. Press ENTER to exit...\n");      
      seqfiles.Subscribe(f => Console.WriteLine(f.ToString()));


      //*********************************************************************************************************************//
      //*** Since we used the ThreadPool scheduler when creating the observable sequence, the enumeration is running on a ***//
      //*** thread from the .NET thread pool. So the main thread is not blocked and can terminate the example if the user ***//
      //*** presses ENTER for a long running enumeration.                                                                 ***//
      //*********************************************************************************************************************//

      Console.ReadLine();
    }
  }
}

下列輸出是使用範例程式碼產生。

Creating subscription. Press ENTER to exit...

C:\Program Files\Common Files
C:\Program Files\IIS
C:\Program Files\Internet Explorer
C:\Program Files\Microsoft Games
C:\Program Files\Microsoft Help Viewer
C:\Program Files\Microsoft IntelliType Pro
C:\Program Files\Microsoft LifeCam
C:\Program Files\Microsoft Lync
C:\Program Files\Microsoft Office
C:\Program Files\Microsoft SDKs
C:\Program Files\Microsoft Security Client
C:\Program Files\Microsoft SQL Server
C:\Program Files\Microsoft SQL Server Compact Edition
C:\Program Files\Microsoft Sync Framework
C:\Program Files\Microsoft Synchronization Services
C:\Program Files\Microsoft Visual Studio 10.0
C:\Program Files\Microsoft Visual Studio 9.0
C:\Program Files\Microsoft.NET
C:\Program Files\MSBuild
C:\Program Files\Reference Assemblies
C:\Program Files\Uninstall Information
C:\Program Files\Windows Journal
C:\Program Files\Windows Live
C:\Program Files\Windows Mail
C:\Program Files\Windows Media Components
C:\Program Files\Windows Media Player
C:\Program Files\Windows NT
C:\Program Files\Windows Photo Viewer
C:\Program Files\Windows Portable Devices
C:\Program Files\Windows Sidebar
C:\Program Files\Zune