如何在管理代码中使用Windows本机dll？

Question

I have made a windows native dll (written in C) which tries to acquire exclusive access of a volume when opening it with CreateFile function. This requires administrative privileges most the time as my dll also tries to lock volume and unmount volume at some point of time. I start my executable project as an administrator from Visual studio 2010 after referencing my dll project in to the solution. To this point, it works fine and my process is able to get exclusive access of the volume.

Now when I release my dll and use it with my GUI program built with QT (also started as an administrator), it is not able to open volume and gives me sharing violation error. I assume that my dll is not able to acquire administrative rights. How should I use my dll so that it can get exclusive access to the volume?

Any help would be appreciated.

Answer 1

Your problem is elsewhere. Elevation is performed by the process when is starts. If the process that hosts your DLL is elevated, then the code in your DLL will execute with elevated privileges.

The error message that you report is a sharing violation, presumably ERROR_SHARING_VIOLATION . That indicates that some other party has opened the volume in a way that blocks sharing. This is not the error that you will receive if you run without elevation. If you attempt to open a volume without sufficient rights, you would see ERROR_ACCESS_DENIED or ERROR_ELEVATION_NEEDED .