DeleteSubKey of previous Application Version/s C#

Question

My application writes user settings to the registry for easy retrieval but this is causing a little headache because it's writing them as version specific.

So each time I update my application it creates a new subkey pertaining to the new version number.

Settings are written to the registry as:

Application.UserAppDataRegistry.SetValue

I would like to find utilize a simple method to delete all the VERSION subkeys that do not match the current Application version.

At the moment and because my application is relatively new I have resorted to this, which does work but is rather untidy:

Registry.CurrentUser.DeleteSubKey("SOFTWARE\\COMPANY\\PRODUCT\\1.0.0.0", false);

Registry.CurrentUser.DeleteSubKey("SOFTWARE\\COMPANY\\PRODUCT\\1.0.10.0", false);

in the above code I have removed the COMPANY & PRODUCT info deliberately & my application is currently on version 1.0.20.0 so at app start the DeleteSubKey lines are run and they are every time the app is run.

I am thinking that something along the lines of using:

If(PreviousVersion != Application.ProductVersion)
{
Registry.CurrentUser.DeleteSubKey(PreviousVersion);
}  

but I am having trouble fleshing this out.

Plus it would be nice to have it only run the one time and not at every startup.

Answer 1

You can list subkeys and check if they're different from current version:

RegistryKey rk = Registry.CurrentUser.OpenSubKey("SOFTWARE\\COMPANY\\PRODUCT");
var keys = rk.GetSubKeyNames();

foreach (string s in keys)
{
   if (s != "Current_verion_number")
   {
      Registry.CurrentUser.DeleteSubKeyTree("SOFTWARE\\COMPANY\\PRODUCT\\" + s);
   }       
}