"Translation exercises" development of Windows Workflow Foundation Program-Preface

Windows Workflow Foundation Program Development-XAML and C #-based WF combat technology and routines

--c# Programmer's WF function and programming Interface technical guidance

Objective

Windows Workflow Foundation (WF) is a technology that defines, executes, and manages workflows. It is. NET Framework version 3.0, and will be integrated into the Windows Vista operating system in the future.

Following the COM + and Distributed transaction Coordinators, WF can be seen as one of the most compelling middleware products on the Windows platform. The difference between WF and the former is that not every software application needs to be distributed, but almost every software implements the workflow within it.

With the help of this book, you can add power to your software on the workflow.

The contents of this book

The 1th chapter introduces the basic concepts of workflow and explains how WF handles problems that exist in workflow solutions. Activity is the basic module for building workflow definitions, and we will make a preliminary impression of them and learn how to use Visual Studio 2005 to develop a simple workflow. This chapter also describes the run-time services provided by WF. After reading this chapter, we will be aware of the basic features of WF.

The 2nd chapter focuses on how the workflow is developed. In particular, we will learn how to build workflows using C # and Extensible Application Markup Language (abbreviated XAML). By using the workflow compiler, we have a more thorough understanding of how WF automatically generates class code from workflow tags through code generators, and how these automatically generated code is combined with our handwritten code to produce a workflow type. This chapter provides some basic knowledge, which helps us understand how WF works during the compilation phase.

In the 3rd chapter, we focus on sequential workflows. We'll take a look at sequenceactivity and learn about event-related knowledge that is raised by the workflow runtime during the lifetime of a workflow instance. With Visual Studio, we can create workflows that can receive parameters and communicate with their host processes in a way that invokes methods and listens for events. In the final part of this chapter, you will introduce a workflow routine in which the workflow first produces an exception and then shows how to capture it with the error handler.

The 4th chapter introduces us to each member of the WF Basic activity library. We learn about control flow activities, communication activities, and transaction-oriented activities. This chapter also mentions Web service activities, rule-based activities, and status activities. The purpose of this chapter is to enable us not only to recognize all the functions of the basic activity library, but also to be aware of the specific issues that each activity can handle.

With knowledge of the basic activity library, we'll try to create a custom activity in the 5th chapter. This chapter first lists the drivers for creating custom activities, and then provides a routine for creating custom activities, and applies 2 methods to the specific development process: combination and derivation. We'll see how to customize validators and designers for custom activities, and we'll also appreciate the benefits of using dependency properties. This chapter concludes with an explanation of the execution context of the activity, which is essential for developing robust activities.

The 6th chapter describes the workflow runtime, workflow diagnostics, and some of the out-of-the-box WF services provided by Microsoft Corporation. This chapter demonstrates how to configure a service using both declarative and programmatic methods. We will learn how to use scheduling services, persistent services, and tracking services through some routines. This chapter provides enough information about WF services, which enables workflow developers to choose and configure the right services to suit their needs when faced with a variety of different scenarios and environments.

The 7th chapter focuses on how to use the state mechanism to build an event-driven workflow. We'll see how WF uses activities to model traditional state machines, and we'll create a workflow that handles external events and drives state transitions. We'll also see how to track and test the execution history of the state machine. In the last part of this chapter, we have studied the layered state machine and mastered this part of knowledge, so we can deal with some difficult problems in the event-driven workflow.

The 8th chapter is related to the work flow letter content. This chapter first describes how to communicate with the host process through related local services, and then explains how to use Web service activities for network communication. Finally, we will learn about the queue service that silently coordinates and transmits messages to the workflow in the background.

The final 9th chapter will explain the rules and conditions used in WF. The role of business rules in software development is discussed here, followed by a routine explaining how WF's rule engine can mitigate the workload of rule development. This chapter provides an in-depth explanation of rule execution in policyactivity and records diagnostic information for rule evaluations. In the final process of the WF program development Journey, we will learn how to use WF to create a rule-based solution.