A lot of people ask if SPD workflows can be customized in Visual Studio so that you can deploy it as a reusable workflow template or add some code to it, and our official answer is that it’s not supported. But... it doesn’t mean it’s not possible to some extent;). In reality, an SPD workflow is a Workflow Foundation XOML file that’s compiled on the fly, so this file can be opened in the Visual Studio Extensions for WF. Today, I’ll show you how to get started;). (It’ll be our little secret!)
I’d strongly recommend having a basic understanding of how VS workflows work prior to reading this (I will probably gloss over some of the VS specific details;)). For general information about building VS workflows, the SharePoint blog is a good place to start.
Also, I should note that this works for workflows that do not have forms. Adding forms can be complex, so I’ll try to cover them in a separate post.
Step 1: Create a VS Workflow Project
In VS, go to File > New and select either a SharePoint Workflow Project (from the WSS or MOSS SDKs) or Workflow Foundation project. You will need Visual Studio Extensions for Workflow Foundation installed.
Step 2: Copy the SPD .xoml and .rules files into the VS project
With the new project in place, we’ll start porting the SPD xoml over to VS. First we need to extract the appropriate workflow files from SPD. To do this, open SPD and go to the Folder List. Right-click on the workflow that you want and choose the Publish Selected Files... option.
In the Remote Web Site tab of the dialog that appears, select the File System radio button and choose a local location on your computer. This will create a folder called Workflows on your file system in the location specified.
When you have these files, rename the .rules file (if you have one) from *.xoml.rules to *.rules. Then add the .xoml and .rules files to your VS project. If you double click on the .xoml file in the Solution Explorer, the WF workflow designer should open, and you should see all your SPD actions in place.
Step 3: Generate a .cs file under the XOML (optional)
If you want to add code behind your XOML, you’ll need a .cs file to go with it. By default, the copied XOML won’t come with this. To generate one, just bind a function to one of the activities in the designer. OnWorkflowActivated is there by default, so try typing an event handler name to its Invoke property. The .cs file created should automatically initialize the namespace and class name to match your XOML. If you don’t like the default names, change the attributes in the first line of the XOML in an XML editor before generating the file:
<ns0:RootWorkflowActivityWithData x:Class="Namespace.ClassName" ...>
Step 4: Deploy and debug the workflow
Fill out the rest of your deployment files and deploy the template as a SharePoint Feature the same way as with any VS workflow, then associate it for use. Since SPD workflows weren’t designed to be ported over, expect some kinks that you’ll have to debug through. But hopefully, the workflow provides enough of a base there to work through them, and with the ability to code, you can find some nifty workarounds;).
Hope this helps!