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Accedere ai file sicuri da una nuova istanza di Excel

Per impostazione predefinita, solo l’istanza di Excel avviata dall’EXE compilato può accedere alla cartella di lavoro sicura e ai relativi file associati. Se si crea una nuova istanza di Excel utilizzando VBA, questa non avrà il permesso di aprire tali file protetti.

Per concedere l’accesso, occorre utilizzare l’API di XLS Padlock allo scopo di trasmettere l’handle della finestra (HWND) della nuova istanza di Excel all’applicazione principale. In questo modo si autorizza la nuova istanza a lavorare con il file system virtuale.

Sub RunInSeparateExcelInstance()
Dim XLSPadlock As Object
Dim appExcel As Object ' Excel.Application
Dim wbExcel As Object ' Excel.Workbook
Dim companionFilePath As String
' Use LongPtr for 64-bit compatibility when getting the window handle.
#If VBA7 Then
Dim windowHandle As LongPtr
#Else
Dim windowHandle As Long
#End If
On Error GoTo Cleanup
' Get the path to a companion file located in the same folder as the EXE.
companionFilePath = GetPathToFileInEXEFolder("data.xlsx")
If companionFilePath = "" Then
MsgBox "Companion file not found.", vbExclamation
Exit Sub
End If
' Get the XLS Padlock API object.
Set XLSPadlock = Application.COMAddIns("GXLS.GXLSPLock").Object
If XLSPadlock Is Nothing Then
MsgBox "XLS Padlock API not available. Is the workbook protected?", vbCritical
Exit Sub
End If
' Start a new, invisible Excel instance.
Set appExcel = CreateObject("Excel.Application")
' Get the window handle (HWND) of the new Excel instance.
windowHandle = appExcel.Application.Hwnd
' Authorize the new instance by passing its HWND to the main application.
' Option "5" is used for this purpose.
XLSPadlock.SetOption Option:="5", Value:=windowHandle
' The new Excel instance can now access the secure companion file.
Set wbExcel = appExcel.Workbooks.Open(companionFilePath, False, True)
' Example: Read a value from the companion workbook.
MsgBox "Value from companion file: " & wbExcel.Worksheets("Sheet1").Cells(1, 1).Value
Cleanup:
If Err.Number <> 0 Then
MsgBox "An error occurred: " & Err.Description, vbCritical
End If
' Close the workbook and quit the new Excel instance.
If Not wbExcel Is Nothing Then wbExcel.Close SaveChanges:=False
If Not appExcel Is Nothing Then appExcel.Quit
' Release object variables.
Set wbExcel = Nothing
Set appExcel = Nothing
Set XLSPadlock = Nothing
End Sub
Public Function GetPathToFileInEXEFolder(ByVal Filename As String) As String
' Helper function to get the full path to a file in the EXE's directory.
' See: https://www.xlspadlock.com/doc/get-the-path-to-a-file-in-the-same-folder-as-the-compiled-workbook
Dim XLSPadlock As Object
On Error Resume Next
Set XLSPadlock = Application.COMAddIns("GXLSForm.GXLSFormula").Object
If Not XLSPadlock Is Nothing Then
GetPathToFileInEXEFolder = Application.BuildPath(XLSPadlock.PLEvalVar("EXEPath"), Filename)
End If
End Function