Shell

From TeamDeveloperWiki

This page covers Windows shell tips & tricks.

Contents 1 How to determine if the current logged-in user is an admin 2 How to delete a whole directory

How to determine if the current logged-in user is an admin

If you want to determine if the current logged-in user (read Windows user) has admin rights, use the function IsUserAnAdmin.

An admin has more authorisations compared to regular users. Some system settings could only be accessible by admins or they are allowed to install software, to register COM libraries or create new network drives.

When your application detects the user is an admin, it could unlock more powerfull features compared to normal users.
For instance, if you want to display more technical error messages or debugging info while running applications, depending
on which kind of user has logged on.

First declare this in external functions section

Library name: SHELL32.DLL
   Function: IsUserAnAdmin
      Export Ordinal: 0
      Returns
         Boolean: BOOL
      Parameters

Usage is simple:

   If IsUserAnAdmin( )
      Call SalMessageBox( "The current user is an admin", "IsUserAnAdmin", MB_Ok )
   Else
      Call SalMessageBox( "The current user is not an admin", "IsUserAnAdmin", MB_Ok )

Here you can download a sample:

• IsUserAnAdmin.zip
  

How to delete a whole directory

Neither VisFileDelete() nor SalFileOpen(..., OF_Delete ) are able to remove a directory from a given file system. For this purpose (and for a number of others) we can use the Windows Shell Function ShFileOperation

Declare the external function:

Library name: Shell32.dll
   Function: SHFileOperationA
      Description:
      Export Ordinal: 0
      Returns
         Number: INT
      Parameters
 	 structPointer
	    Window Handle: HWND
	    Number: UINT
	    String: LPSTR
	    String: LPSTR
	    Number: DWORD
	    Receive Boolean: BOOL
	    Number: LPVOID
	    String: LPSTR

We will need at least these constants:

Number: FO_DELETE          = 0x0003
Number: FOF_NOCONFIRMATION = 0x0010

Now, we are able to build a method like this:

Function: RemoveCompleteDirectory
   Description: Removes a complete Directory with all 
                subdirectories and files.	
		
                No user confirmation required!
   Returns	
      Boolean:
   Parameters
      String: p_sDirectory
   Static Variables
   Local variables
      Boolean: l_bCancelled
      Number: l_nRet
   Actions
      Set l_nRet = SHFileOperationA( hWndForm, 
                                     FO_DELETE, 
                                     p_sDirectory, 
                                     STRING_Null, 
                                     FOF_NOCONFIRMATION, 
                                     l_bCancelled, 
                                     NUMBER_Null, 
                                     "Deleting Directory..." )
      !				     
      Return l_bCancelled = FALSE AND l_nRet = 0

Have a look at ShFileOperation in MSDN for more sophisticated usages and options.