How does clickonce know what to run when not connected to internet

When you use ClickOnce to deploy an application, there is a appref-ms file that holds the url to the main application, for example localhost or a shared folder. When you are connected to the netwo开发者_开发知识库rk, this file can locate the .application file and run the program.

How does this work when not connected? My program starts normally (but no data from database which is normal because it's on a remote server). How does he know what he needs to start? The .application is not on the local disk, as far as i know.

If you look at your system's file types, you can see that appref-ms files are opened with the "ClickOnce Application Deployment Support Library". This support libary is just dfshim.dll.

dfshim.dll does the actual work. It attempts to find a new version using the url from the appref-ms file. If it can't connect or if there isn't an update, it simply starts the local ClickOnce app.