How does a single .Net EXE update itself?

If you've used Lutz Roeder's Reflector, you know that the app can delete & download a new version of itself. It must be a Windows service, right? Anyone knows how that's done?

I like portable apps that can update & move itself if requested.

You don't need a Windows service to do this.  An application can make a copy of itself somewhere (the temp directory), reload as that copy, and then replace the original with the new version after download.  And it's simple to guess from this explanation how such an application could move itself.

One really annoying thing about the .net reflector though is that it doesn't take Proxies into account, so it often just deletes itself from my machine and I need to re-download it when it tries to get a newer version and fails  

kidzi wrote:

One really annoying thing about the .net reflector though is that it doesn't take Proxies into account, so it often just deletes itself from my machine and I need to re-download it when it tries to get a newer version and fails  

Minh wrote:



kidzi wrote: One really annoying thing about the .net reflector though is that it doesn't take Proxies into account, so it often just deletes itself from my machine and I need to re-download it when it tries to get a newer version and fails

Yep! I keep a ZIP version around for this reason. But I wonder about the conditions that cause this failure...

What I learned by talking to someone who knows the author is that there are two different mechanisms. First, after a while Reflector asks for updates. If you don't update for another few weeks it forces you to update. Second, Reflector deletes itself when closing the app if the EXE file is really old. Apparently there was a two day overlap between the two in one version so a few folks unintentionally got there files deleted. This should not happen on newer versions. Keeping a zip around won't help as the file in the zip will show the same update behavior.

netcodex wrote:



What I learned by talking to someone who knows the author is that there are two different mechanisms. First, after a while Reflector asks for updates. If you don't update for another few weeks it forces you to update. Second, Reflector deletes itself when closing the app if the EXE file is really old. Apparently there was a two day overlap between the two in one version so a few folks unintentionally got there files deleted. This should not happen on newer versions. Keeping a zip around won't help as the file in the zip will show the same update behavior.

What would be the point preventing the file from updating by making it read-only? If it is time-bombed you'd be just holding onto a stale EXE. From description above it sounds like the self-delete was an accident and it will update normally without deleting in the future.

The worst update behavior for any software is that you have to go to the store and pay lot of money for a new version (in some cases pay for a new computer to run the new version).



Joking aside, for a free dev tool Reflector's update is awesome. It is simple, it works and it supports dynamic proxy settings which most .NET apps don't.