以下是摘录的关于Workflow instance的一段话。描述了instance和workflow从概念上的区别。
Note: A workflow definition is what you ask workflow runtime to execute, whereas an instance is an executing workflow definition. There is a distinct difference. One is executing and the other is not. However, I'll use the terms interchangeably throughout this chapter, and even in the rest of the book, because in the end we're interested in executing software, not just in writing it. Besides, "instance" rolls off the tongue more easily than does "workflow definition".
WorkflowInstance is the WF object that gives your individual workflow task context.
Method:(仅仅摘录一些比较重要的部分)
Resume:If the workflow instance is not in the suspended state, nothing happens. If the workflow instance is the suspended state, the workflow runtime raise the WorkflowResumed event just before the workflow instance execution is resumed.
Start:……, calling ExecuteActivity on the root activity of this workflow instance.
Suspend:……. If the instance is running, the workflow runtime suspends the workflow instance, sets SuspendOrTerminateInfoProperty to the string(reason) passed into Suspend, and raises the WorkflowSuspended event.
引用：
以上文字摘抄自《Microsoft Windows Workflow Foundation Step By Step》P39-42