Windows Workflow Foundation (I): Basic Concepts

I picked up my girlfriend at the airport yesterday and took a book titled presenting windows Workflow Foundation beta Edtion, I found some new gains (this is the legendary book read hundreds of times, and its meaning is self-existent? More practical applications will be added ).
I want to write a series to give a full introduction, but I don't know if I can stick to it.
The content to be written is as follows:
1: Basic Concepts/Structures
2: communication, simple example
3: activtiy introduction, focusing on dataactivity and activity development
4: Applications in office
5: statemachine Workflow
6: Host

Let's start with the first article: Basic Concepts/structures.

With the emergence of various platforms and middleware, application software is becoming more and more like assembling automobiles. Although we are still in touch with those products, we will focus on how to deal with the customer's business processes (it was no longer the basic work of thinking about how to display a beautiful button ), this is the value of the application workflow.

The first time I met this WWF, I still wrote something in February. Before that, I used jjx's osworkflow for. net. There are other workflows such as k2 on the market. For more information, see bepl.
The current WWF is still in beta version. However, the design ideas and concepts should not change significantly.

let's take a look at the WWF structure (not very easy to draw)
1: workflow model layer
sequential; statemachine; policy; customer activities (self-developed)
activity and rule authoring APIs
2: runtime layer
workflow execution: sched; rules; tracking infrastructure
workflow lifecycle management: statemanagement; activation
3: hosting layer
runtime services: persistence; Communication; timer; tracking; transactions; threa Ding
Custom Services
is hostprocess.

let's look at it one by one.
1: workflow model layer:
sequencial Workflow Model: A workflow that is executed sequentially. It is actually a self-driven workflow in a small scope. For example, if the execution is 1 or 2, then execute 4, and fail to execute 5,... in this scope, the execution can be completed by itself without the driver of external events.
statemachine workflow model: state machine workflow. This type of workflow is an event-driven workflow. The flow is driven by external events, rather than specific and predictable processes in the local area. For example, if someone triggers Event 1 and then enters state 2, in state 2, if someone triggers event 3, then proceed to the next process ....
do you see their differences? It is important to understand this .

2: runtime layer:
Execution: Execution
Statemanagement: processing the persit status.
Scheduler: scheduled task
Rules: rules and conditions. There is a complex ruleset that requires special introduction (learning notes for ruleengine in winsows Workflow Foundation ).
3: hosting layer:
Persistence is used to store context. Because the workflow may run for a long time or every long time, the current context must be saved, databases, XML files, and so on. By default, an sqlserver database provider is available (I tried to write a MySQL service, but there is not much information ).
Timer: scheduled task. By default, an sqlserver database provider is available.
Communication: Communication Between wrokflow and host. You can use components or webserice.

 
Action: acitity. This is the core of a workflow execution task.
In osworkflow, these actions are called actions. Here (WWF), we call this processing acitity.
Actity is divided into many types, and their classification and meaning will be detailed next time.

About Design:
WWF designer visualization is good, osworkflow is not good, that tool is uncomfortable, manual Writing of XML is too tired, it is easy to make mistakes.

By the way, it is said that office12 supports WWF.

This time I wrote so much: structure, hierarchy, process classification, processing, and designer.