我正在尝试为WF 4实现自定义TrackingParticipant。我可以编写Track方法,但我的实现速度很慢。
如何使用.NET 4.0的任务并行库(TPL)实现Begin / EndTrack覆盖?我看过TPL and Traditional .NET Asynchronous Programming,但不知道如何在这里应用它。
请注意,TrackingParticipant是.NET的一部分,并且使用虚拟方法预定义了经典异步模式。
public class MyTrackingParticipant : TrackingParticipant
{
protected override IAsyncResult BeginTrack(
TrackingRecord record, TimeSpan timeout,
AsyncCallback callback, object state)
{
// ?
}
protected override void EndTrack(IAsyncResult result)
{
// ?
}
protected override void Track(TrackingRecord record, TimeSpan timeout)
{
// synchronous code to be called
}
}
答案 0 :(得分:18)
这是实现经典APM编程模型的通用模式:
protected override IAsyncResult BeginTrack(TrackingRecord record, TimeSpan timeout, AsyncCallback callback, object state)
{
Task result = Task.Factory.StartNew(
(taskState) =>
{
// ... your async work here ...
},
state);
if(callback != null)
{
result.ContinueWith((t) => callback(t));
}
return result;
}
protected override void EndTrack(IAsyncResult asyncResult)
{
// Call wait to block until task is complete and/or cause any exceptions that occurred to propagate to the caller
((Task)asyncResult).Wait();
}
如果EndXXX方法返回结果,您实际上会返回Result
的{{1}}属性,而不是仅调用Task
。例如:
Wait