Be careful when hosting your web site based on DasBlog from a Windows XP machine. While IIS 6 in Windows 2003 prevents the download of files with unknown extensions by default, the IIS 5.1 in Windows XP allows downloading such files. In the case of DasBlog all *.blogtemplate files are at risk. There are a few sites out there where these files can be downloaded. Although this probably isn’t a big security risk it might be something you want to prevent. Probably the easiest way to do that is by modifying the web.config file. You should add the following line at the end of the <httpHandlers> section:

<add verb="*" path="*.snippet" type="System.Web.HttpForbiddenHandler" />

DasBlog – the weblog engine this site is running on – allows extensibility through macros. You’ll need to use them as soon as you want any additional dynamic content on your site. (The ads you can see at the bottom of the right side bar are an example of a macro which I’ve recently updated to make the ad selection a little more advanced.) The documentation doesn’t mention their development at all therefore the following post by Vasanth Dharmaraj is probably the best source of information available on it. It actually discusses everything you need to know to get going. Make sure you read it before trying to write your first macro.

Before using EventLog.WriteEntry for adding events to event log you should consider calling EventLog.CreateEventSource to make your application a valid source of events. Keep in mind though that you need administrative privileges for it succeed, therefore it is best to call it at installation time. So, if you want to write to the application event log by calling:

EventLog.WriteEntry("MyApplicationName", "My event text");

don’t forget doing this first:

if (!EventLog.SourceExists("MyApplicationName"))
   EventLog.CreateEventSource("MyApplicationName", "Application");

If you want to view EPS images with IrfanView you need to have AFPL Ghostscript installed. I spent quite some time investigating why it worked on one machine and not on the other before I checked the IrfanView plug-ins web page where I found this useful bit of information.

Essentially everything you need to implement plug-ins in your application is some way to dynamically instantiate classes at runtime. As long as they all implement the same interface, you just use it to access its properties and methods.

In COM world this was achieved by calling the CreateObject function. In the managed world you should use AppDomain.CreateInstanceAndUnwrap as demonstrated by the following example:

IBind pluginInstance = (IBind)AppDomain.CurrentDomain.CreateInstanceAndUnwrap("MCPP", "DamirsCorner.Samples.LateBinding.MCPP");

Everything you need to know at runtime is the full class name (including the namespace) and the containing assembly. To get those you can either require their previous registration within the application or you can dynamically discover them by loading assemblies from a predefined location (Assembly.Load or Assembly.LoadFrom) and enumerating their classes (Assembly.GetTypes) whichever suits you situation best.