C# - 簡單介紹TaskScheduler

task Scheduler根據定義

The task Scheduler by the definition blurb.

“Is the class where the usage context is within the task libraries. “

它的作用像是WPF/Winform時代的SynchronizationContext.

It is like the Synchronization context in the cross WPF/Win forms era.

像SynchronizationContext.一樣，TaskScheduler也有可能依賴特定的UI SynchronizationContext.

As with the Synchronization context, we may have requirement for like the UI context synchronization.

代碼如下:

Give the code as below.

1. ///<summary>
2. ///ThisserviceisdesignedtoreturnaTaskSchedulerforapplication'smain,UIthread.
3. ///ThisserviceMUSTbeinstantiatedonUIthread.
4. ///</summary>
5. [DebuggerNonUserCode]
6. publicclassUITaskSchedulerService:IUITaskSchedulerService
7. {
8. PRivatestaticreadonlyUITaskSchedulerServiceInstanceField=newUITaskSchedulerService();
9. privatestaticreadonlyTaskSchedulerTaskSchedulerUI;
10. privatestaticreadonlyThreadGuiThread;
12. staticUITaskSchedulerService()
13. {
14. GuiThread=Thread.CurrentThread;
15. TaskSchedulerUI=TaskScheduler.FromCurrentSynchronizationContext();
16. }
18. ///<summary>
19. ///Getstheinstance.
20. ///</summary>
21. publicstaticUITaskSchedulerServiceInstance
22. {
23. get
24. {
25. returnInstanceField;
26. }
27. }
29. ///<summary>
30. ///GetTaskSchedulertoscheduleTasksonUIthread.
31. ///</summary>
32. ///<returns>TaskSchedulertoscheduleTasksonUIthread.</returns>
33. publicTaskSchedulerGetUITaskScheduler()
34. {
35. returnTaskSchedulerUI;
36. }
38. ///<summary>
39. ///CheckwhethercurrenttreadisUItread
40. ///</summary>
41. ///<returns><c>true</c>ifcurrenttreadisUItread.</returns>
42. publicboolIsOnUIThread()
43. {
44. returnGuiThread==Thread.CurrentThread;
45. }
46. }

該class的要求是必須在UI thread初始化。

The requirement for the UITaskShcedulerService is that you should construct the singleton instance to start from a UI threads.

因為他內部使用的是TaskScheduler.FromCurrentSynchronizationContext，根據MSDN的TaskScheduler Class定義，它拿到的是當前thread的synchronization context

Because it internally use theTaskScheduler.FromCurrentSynchronizationContext. and from theTaskScheduler Classfrom MSDN, it retrieve the current thread’s synchronization context.

1. Task.Factory
2. .StartNew(
3. ()=>
4. _riskProvider.GetRiskPnL(),
5. CancellationToken.None,
6. TaskCreationOptions.None,
7. TaskScheduler.Default)
8. .ContinueWith(
9. (task)=>ProcessResults(task.Result),
10. UITaskSchedulerService.Instance.GetUITaskScheduler(