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20181118

TaskScueduler 抽象類別
Represents an object that handles the low-level work of queuing tasks onto threads.
public abstract class TaskScheduler
TaskScheduler 代表處理底層執行緒的佇列工作抽象物件.
TaskScheduler是抽象類別, 只能被繼承使用.

An instance of the TaskScheduler class represents a task scheduler. A task scheduler ensures that the work of a task is eventually executed. 
由TaskScheduler建立的物件代表工作排程. 工作排程可確保工作確實被執行.

The default task scheduler is based on the .NET Framework 4 thread pool, which provides work-stealing for load-balancing, thread injection/retirement for maximum throughput, and overall good performance. It should be sufficient for most scenarios. 
預設的工作排程Task Schuduler, 是建立在.net 4.0的執行緒池thread pool上, 能提供負載平衡, 線程注入/引退, 最大的吞吐量, 以及整體良好的效能. 可滿足大部分的需求情境.

The TaskScheduler class also serves as the extension point for all customizable scheduling logic. This includes mechanisms such as how to schedule a task for execution, and how scheduled tasks should be exposed to debuggers. If you require special functionality, you can create a custom scheduler and enable it for specific tasks or queries. 
TaskScheduler類別提供可自訂的擴充功能. 包括可自訂如何執行工作, 和如何除錯. 若需要特殊的功能, 可以建立自訂的排程工作或查詢.