Today, I began to experiment on MS WF.
I find very useful the possibility to load at runtime a xaml file of my personal workflow.
To reach my goal I create two project with VS 2008 to test my solution:
- A console project which is the entry point of my application;
- A workflow library where put my custom activity and sequence workflow.
In my workflow library I add a xaml file where I put only my custom simple sequence with only one custom activity that print a "Hello world" (see the figure below).
Remember that the custom activity must be tagged as [Serializable].
My xaml file hasn't the code behind because I built my workflow in declarative manner. If you take look at xml you could see:
<SequentialWorkflowActivity x:Name="Workflow1"
xmlns:ns0="clr-namespace:MyWorkflowLibrary.Task;
Assembly=MyWorkflowLibrary, Version=1.0.0.0, Culture=neutral,
PublicKeyToken=null"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/workflow">
<ns0:HelloWorldTask x:Name="helloWorldTask1" />
</SequentialWorkflowActivity>
Note that I remove the x:Class attribute in SequentialWorkflowActivity. I do that because I haven't the compiled class in the code behind. In namespace attribute I add the reference to the assembly container of my activity, because this will be resolved at runtime.
The console application "Main" looks something like this:
static void Main(string[] args)
{
// Here, I read my xaml file containing my declarative workflow
var xmlReader =
new XmlTextReader(
new StringReader(
File.ReadAllText(
@"C:\Users\simonem\Documents\Visual Studio 2008\Projects\
TestWorkflow\MyWorkflowLibrary\HelloWorld.xoml")));
var runtime = new WorkflowRuntime();
runtime.StartRuntime();
runtime.WorkflowCompleted += delegate
{
Console.WriteLine("WorkFlow completed");
Console.Read();
};
try
{
var instance = runtime.CreateWorkflow(xmlReader);
instance.Start();
}
// Here I manage potential workflow validation exceptions
catch(WorkflowValidationFailedException wfve)
{
var errorValidation = string.Empty;
foreach (var error in wfve.Errors)
{
// StringBuilder is better...
errorValidation += Environment.NewLine + error.ErrorText;
}
Console.WriteLine(errorValidation);
}
// General exceptions
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Console.Read();
}Troubleshooting:
- If during the program execution you receive an error such as "Could not deserialize object. The type 'clr-namespace:MyWorkflowLibrary.Task;.HelloWorldTask' could not be resolved. startIndex cannot be larger than length of string.Parameter name: startIndex" remember to specify the assembly reference in workflow xml code (see below):
<SequentialWorkflowActivity x:Name="Workflow1"
xmlns:ns0="clr-namespace:MyWorkflowLibrary.Task;
Assembly=MyWorkflowLibrary, Version=1.0.0.0, Culture=neutral,
PublicKeyToken=null"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/workflow">- If you couldn't compile your solution and you receive the following error "Cannot compile a markup file which does not contain declaration of the new workflow type." you must change the build action on your xaml file from "Content" to "None".
References:
My xaml file hasn't the code behind because I built my workflow in declarative manner. If you take look at xml you could see:
After a long and 
Open context menu from ASP.NET Impersonation:
Repeate the steps above also for the WSS site (in my case is the "Default Web Sites").
Remember that new TFS users must have also the permission in WSS site and in Reporting Service. To accomplish this requirement take a look to the screenshot below (IMHO is very usefull create a users group in your machine named TFS_Users and use it...):
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