API to toggle "Show hidden files, folders and drives"

Question

Is there a function in Windows API to toggle the "Show hidden files, folders and drives" option in Windows Explorer (Tools >> Folder Options... >> View tab).

I know of a related registry key, but changing that would not have immediate effect. The key is: HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows/CurrentVersion/Explorer/Advanced/Hidden

Trying to do this from C#, but the question is not language-specific.

Answer 1

You could try the options the OP in this thread suggests, that is:

Either

 SendNotifyMessage(HWND_BROADCAST, WM_SETTINGCHANGE, 0, 0);

or

 RefreshPolicyEx(False, RP_FORCE);

or

 SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, 0, integer(pchar('Policy')), SMTO_NORMAL or SMTO_ABORTIFHUNG, 5000, c1);

These are not in the .NET C# API, so you'll have to use DllImport

Edit: formatting

Answer 2

In addition to the comment I've added to the original question - if you're doing this so that, for instance, the OpenFileDialog you're about to pop open shows these files - don't do it.

In that case, you're better P/Invoking GetOpenFileName, and setting the appropriate option (OFN_FORCESHOWHIDDEN (see enum for a related subject) in the flags of the OpenFileName structure.

That way you're only affecting your application, at the appropriate time