This is driving me crazy and has resulted in lost work (not much, at least).
Normally, when I edit a file in Visual Studio, it's supposed to automatically check that file out in source safe. On multi-project solutions (e.g., web app with class libraries), sometimes none of the files in one project would automatically get checked out, though exiting & reloading visual studio may fix that problem temporarily. Furthermore, project files are never automatically checked out. Whenever I add/remove code files, I have to remember to explicitly check out the project file as well (otherwise we'll have issues with code files not showing up in the solution explorer, or trying to load non-existing files).
We're using VS-2008 and VSS 2005. Do you have any idea how I might fix this? There are no more visual-studio updates/fixes on Microsoft Update.
You need to ensure the files are read-only, or VS won't be able to tell that they are version controlled (or, at least that's what it uses to determine it). You can tell VSS to set itself up so getting the latest version places the files RW on disk.
There may be other problems here, but that's what comes to mind first. My advice (that I took myself) is to migrate to SVN or an alternative. Losing work is unacceptable.
来源：https://stackoverflow.com/questions/783738/why-dont-files-automatically-get-checked-out-from-vss-when-i-edit-them