Visual Basic Programming Code Examples

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Encrypt a file-folder (Windows 2000)



Encrypt a file-folder (Windows 2000)

The following routine can be used to encrypt/decrypt a file or folder using Windows 2000.

Private Declare Function EncryptFile Lib "ADVAPI32" Alias "EncryptFileA" (ByVal lpFileName As String) As Boolean
Private Declare Function DecryptFile Lib "ADVAPI32" Alias "DecryptFileA" (ByVal lpFileName As String, ByVal dwReserved As Long) As Boolean


'Purpose     :  Encrypts a file or directory.
'Inputs      :  sFileOrPath             The file or path to encrypt
'Outputs     :  Returns True on success
'Notes       :  All new files created in an encrypted directory are also encrypted.
'OS          :  Windows 2000 with NTFS 5 ONLY.


Function FileEncrypt(sFileOrPath As String) As Boolean
    On Error Resume Next
    FileEncrypt = EncryptFile(mFile)
End Function


'Purpose     :  Decrypts a file or directory.
'Inputs      :  sFileOrPath             The file or path to encrypt
'Outputs     :  Returns True on success
'Notes       :  All new files created in an encrypted directory are also encrypted.
'OS          :  Windows 2000 ONLY


Function FileDecrypt(sFileOrPath As String) As Boolean
    On Error Resume Next
    FileDecrypt = DecryptFile(mFile, 0)
End Function

'Demonstration routine
Sub Demonstration()
    If FileEncrypt("C:\smile.txt") Then
        MsgBox "File Encrypted...", vbInformation
        Shell "notepad c:\smile.txt"
        If FileDecrypt("C:\smile.txt") Then
            MsgBox "File Decrypted...", vbInformation
        End If
    Else
        MsgBox "You need Windows 2000 to use this API...", vbInformation
    End If
End Sub