Installing and debugging a .NET service built in Visual Studio 2008

There seem to be several tutorials on the web on how to create a Windows service using .NET in Visual Studio 2005 and before but I was unable to find one for Visual Studio 2008, so thought I’d write my own since I got tripped up a couple of times when I tried to install it.

The first step is easy, create a new project using New Project/Windows Service. The next obvious thing to try and do is to build it and run it. You will then be presented with the following error -

Cannot start service from the command line or a debugger.  A Windows Service must first be installed (using installutil.exe) and then started with the ServerExplorer, Windows Services Administrative tool or the NET START command.

So then you fire up installutil from the command line passing the EXE’s full path as the only parameter. If you make my schoolboy error, you’ll be faced with the following error message -

Exception occurred while initializing the installation: System.BadImageFormatException: The format of the file 'WindowsService1.exe' is invalid.

This is because I ran installutil from the standard command prompt, rather than the .NET command prompt and it picked up installutil from the .NET Framework 1.1. So when I figured that out I ran the correct version of installutil and got the following error message -

No public installers with the RunInstallerAttribute.Yes attribute could be found in the C:\Source\dotNET2\WindowsService1\WindowsService1\bin\Debug\WindowsService1.exe assembly.

So the next thing to do is to add an installer to the service. This is achieved by right clicking on the service’s design surface and selecting ‘Add Installer’. after doing this and running installutil once again, the service should appear in the Services applet.

Finally, to debug it you’ll need to start it from the Services applet and then use the ‘Debug/Attach to Process…’ menu item in Visual Studio, making sure the ‘Show processes in all sessions’ checkbox is checked if the service is running under a different account to your own.

Regards WTF?

When I was a young lad and was taught how to write a letter (a skill that has turned out to be not especially useful) I was told to end the letter with “yours sincerely”, which kind of baffled me at the time and still does. What does it mean, why would I want to be owned by the reader of the letter? why would I not be sincere?

And now, when my most of communication is via email, I’m receiving more and more of them ending with “regards” or “kind regards”. And now I’m asking myself the same question - what does that mean? It’s even happening with people I’ve known for years who have never put any strange incantations at the end of their emails in the past and have now started this odd practice. I guess emails are the new letters and we have to have some way of signing off from them. I’d always thought of emails as a fairly informal medium, but perhaps not anymore.

Regards Doogal

Virtual PC on Windows 7

I decided to jump in and upgrade to Windows 7, because I keep hearing it’s what Vista should have been. And it’s OK. I think I’m getting too old to get excited about OS upgrades, these days I just get annoyed about what’s been broken.

But today I had need to fire up a virtual machine so launched Virtual PC 2007. It told me it was unable to get the network connection up and running and offered to fix it, but then couldn’t find the location of my setup files. Not to worry I thought, probably the best plan is to just reinstall the whole thing. So I uninstalled then attempted to re-install but was told Virtual PC 2007 doesn’t work on Windows 7 so it refused to install it (even though it was clearly working at least a little bit for me). But then I noticed there was a new version of Virtual PC available that would work on Windows 7. So I downloaded that to try and fix my problem. Unfortunately this new version of Virtual PC requires a CPU that has virtualisation built-in. Sadly my CPU is lacking that feature so I couldn’t install this new version.

So if you have Windows 7 and a CPU that doesn’t have the right features then you are basically stuffed. I have managed to get round the problem by rolling back my Windows installation a couple of days using System Restore. Virtual PC 2007 seems to work fine except for the lack of network support, but if you don’t already have Virtual PC installed then you will be somewhat stuck.

Using the StateDropDownEditor in state machine workflows

Many moons ago I wrote about creating custom state machine activities. I’ve finally got back to doing some more work on this and thought it would be nice to add a dropdown to choose the target state for my custom activity. This looks pretty easy to implement, just decorate the property with the following attribute

[Editor(typeof(StateDropDownEditor), typeof(UITypeEditor)), DefaultValue((string) null)]

Unfortunately, StateDropDownEditor is an internal class so this won’t compile. The way round this is to fire up Reflector and copy the code for the StateDropDownEditor class. Not sure what the copyright issues are for this, but it starts to solve the problem. Unfortunately the StateDropDownEditor class references a StateMachineHelpers class which is also internal. We can again use Reflector to get hold of the implementation of this class, but things can start to get messy at this point. We end up having to pull in pretty much the whole state machine infrastructure code but the solution is pretty simple, just remove the GetCurrentState method and then no more code needs to be ‘borrowed’. I now have a nice dropdown for selecting the target state.

Poor man's profiling

If you don't have access to a profiler or you can't be bothered to fire up your profiler to see where you've got performance problems, there's a pretty simple way to find performance bottlenecks in your code. Just keep breaking into your code and if a particular piece of code is causing problems, then chances are you will keep being taken to that piece of code.