Essential Windows Workflow Foundation

1. Deconstructing WF

INTRODUCTORY PROGRAMMING TEXTS often begin with a “Hello, World” program that prints a simple message to the standard output device. Here’s that program in C#:

using System;class Program{  static void Main()  {    Console.WriteLine("hello, world");  }}

Hello, World is a popular starting point because it avoids a number of hard problems that most real-world programs need to address. Practitioners know that it doesn’t take much work to expand even Hello, World to induce thorny problems rather quickly. For example, consider a simple variation—let’s call it “Open, Sesame”—that requires the user to enter a key before the traditional greeting is printed:

using System;class Program{  static void Main()  {    // Print the key    string key = DateTime.Now.Millisecond.ToString(); ...