I'm working on a SharePoint project where several componenets (Workflow, List Definitions, Content Types, etc.) are tightly related to the same functionality. To reduce the risk of components breaking because of an out-of-sequence or missing dependency, and just to make things easier, I wanted to throw everything together in the same project. I discovered something interesting about Workflows in the process, however.

Namely, if you try to add a Workflow to a typical project, you'll get an error in the Workflow designer saying:

     "The service 'System.Workflow.ComponentModel.Compiler.ITypeProvider' must be installed for this operation to succeed."

This happens if you added references to the proper assemblies (System.Workflow.Activities, System.Workflow.ComponentModel, System.Workflow.Runtime and microsoft.sharepoint.WorkflowActions)!

Odd, but luckily there are solutions. One is to write a bunch of code to build the support that the Workflow Designer needs, but I was looking for something even simpler. What I discovered, is that you can add support for Workflows to your project (the .csproj or .vbproj file) by cracking it open in notepad and adding some "ProductTypeGuids" to the project XML. Just add both of the GUIDs featured in the ProjectTypeGuids element below (or add the element if it's not there), and you should be good to go!

 I'm curious to see if you can add these GUIDs to many types of projects to enable Workflow support (and further curious about if there are any consequences apart from designer support),

 There are a variety of techniques out there for wiring up a CSS class to an ASP.NET Web Form through code. You can register a link to a CSS file via Page.Header.Controls.Add() and ASP.NET 2.0 introduced the robust WebResource framework for registering entire style sheets for a given page, but what about when you want to add a dynamic style to the HTML  header?

Typically, the technique would involve something like this:

...but there are drawbacks to the approach including the need for verbose "style" tags with each chunk of CSS styles you want to add and the lack of validation on style names and values.

Luckily, there's a more sophisticated and elegant approach supported by .NET Framework 2.0 or higher using Page.Header.Stylesheet and the System.Web.UI.WebControls.Style class. With the approach, instead of having to define your CSS class using a string, you can used strongly-typed objects instead! Additionally, all of the styles you add will get added to one single style attribute in the Page header.

There is, however, a drawback to the approach which is the limited number of properties available in the Style base class. For instance, if you wanted to set a value for the "margin" CSS style, you'd need to either use or create a subclass of Style that overrides the AddAttributesToRender() method.

In ASP.NET 1.x, it used to be common to handle the getter of a value type properties thusly:

Not bad, but there's more code than needed with nullable types and the "null coalescing operator", anyway. Here's the newer, sleeker way to do the same thing with half the space!

So what's going on in this snippet? Well, we cast the value to a nullable int (int?) which holds a reference to either an int or null then we use the aforementioned ?? operator to return our default value or 0 in the case of null.