恢复一个持久窗口工作流程4活动在不知道具体的活动形式 [英] Resuming a persisted Window Workflow 4 Activity without knowing concrete type of activity

问题描述

我想知道如何能恢复（加载）previously坚持WF4活动不知道具体类型的活动。

I am trying to understand how one can resume (load) a previously persisted WF4 activity without knowing the concrete type of the activity.

为了加载一个持久的活动，我不仅需要其 workflowId （我有），但我需要传递活动的一个实​​例过 - 所以我需要知道它的类型：

In order to load a persisted activity, I not only need its workflowId (which I have), but I need to pass in an instance of the activity too - so I need to know it's type:

var workflowApplication = new WorkflowApplication(activity); // what type is activity?
workflowApplication.Load(workflowId);

的问题是，它可以是若干类型中的一种 - 该活动旨在被其他活动和工作流程内使用：它发送一个消息到消息队列，书签，然后持续存在。当通过消息队列接收到相应的消息就会恢复，但我不知道确切的具体类型原来的工作流程，而不检查持久性数据。这似乎是左右为难的。无需加载工作流程，检查其持续的数据不知道活动类型我无法加载工作流程，而且我不知道该活动类型。

The problem is that it could be one of a number of types - this activity is intended to be used within other activities and workflows: it sends a message to a message queue, bookmarks and then persists. It is resumed when a corresponding message is received via the message queue but I don't know the exact concrete type of the original workflow without examining the persistence data. This seems like catch-22. I can't load the workflow without knowing the activity type, and I can't know the activity type without loading the workflow and examining the its persisted data.

我觉得我失去了一些东西 - 有没有一种方法来创建一个托管WorkflowActivity不知道该活动，还是有办法来重新加载持久性数据制定的实际类型活动创建前的 WorkflowActivity ？

I feel like I'm missing something here - is there a way to either create a hosting WorkflowActivity without knowing the activity, or a way to reload the persistence data to work out the actual type of activity before creating the WorkflowActivity?

推荐答案

有没有原生支持通过WF API来做到这一点，你要拿出自己的解决方案。

There's no native support to do it through WF API, you've to come up with your own solution.

最快的方法：存储扩展的使用InstancePromotedProperties表保存你自己的属性。

The fastest approach: Store Extensibility to use InstancePromotedProperties table to save your own properties.

可能是正确的做法：<一href="http://msdn.microsoft.com/en-us/library/system.activities.persistence.persistenceioparticipant.aspx"相对=nofollow> PersistenceIOParticipant 似乎这样做的正确方法。只要创建自己的表来存储任何你想要的，包括活动的类型。

Probably the correct approach: PersistenceIOParticipant seems the correct way of doing it. Just create your own table to store whatever you want including activity's type.

使用自定义活动，以节省为你的某个地方，之前一直存在。不是最好的，也不正确这样做了各种各样的原因的方法。

Use a custom activity to save it for you, somewhere, before persist. Not the best nor correct way of doing it for a variety of reasons.

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