A volte può essere utile gestire la finestra di dialogo Apri, quella cioè che ci permette di navigare tra le nostre cartelle, selezionare il file ed aprirlo con l’applicazione appropriata. Di seguito sono riportati 2 moduli, il primo permette di avviare la finestra di dialogo e gestire alcune proprietà della finestra, il secondo contiene le API.
Dim sFileName As String
Dim udtFileDialog As FileDialog
Dim PercorsoDaAprire As String

Sub ApriExpl()
‘
‘Imposto le proprietà della finestra
With udtFileDialog
.CustomFilter = “Tutti i file (*.*)” _
& Chr$(0) & “*.*” & Chr$(0) & Chr$(0)
.DefaultExt = “*.*”
.Title = “Sfoglia”
.InitialDir = “C:\”
End With
‘Salvo il percorso da aprire
PercorsoDaAprire = WinFileDialog(udtFileDialog, 1)
‘ Se devo aprire un file excel uso il metodo Open _
‘ altrimenti la funzione ShellExecute
If PercorsoDaAprire <> “” Then
If Right(PercorsoDaAprire, 3) = “xls” Then
Workbooks.Open PercorsoDaAprire
Else
Call LoadMiscFiles
End If
End If

End Sub

Sub LoadFile(FileName As String)
ShellExecute 0, “Open”, FileName, “”, “”, 1
End Sub

Sub LoadMiscFiles()
LoadFile PercorsoDaAprire
End Sub

Di seguito il secondo modulo contenente le WinAPI.
‘————————————————-
‘ Dichiarazioni WinAPI
‘————————————————-
Private Declare Function GetOpenFileName% _
Lib “COMDLG32″ _
Alias “GetOpenFileNameA” ( _
OPENFILENAME As OPENFILENAME _
)
Private Declare Function GetSaveFileName _
Lib “comdlg32.dll” _
Alias “GetSaveFileNameA” ( _
pOPENFILENAME As OPENFILENAME _
) As Long
Private Declare Function GetModuleHandle _
Lib “Kernel32″ _
Alias “GetModuleHandleA” ( _
ByVal lpModuleName As String _
) As Long
Private Declare Function GetActiveWindow _
Lib “user32″ ( _
) As Long
Declare Function ShellExecute Lib “shell32.dll” _
Alias “ShellExecuteA” ( _
ByVal Hwnd As Long, _
ByVal lpOperation As String, _
ByVal lpFile As String, _
ByVal lpParameters As String, _
ByVal lpDirectory As String, _
ByVal nShowCmd As Long _
) As Long

‘————————————————-
‘ Tipi definiti dall’utente
‘————————————————-
Private Type OPENFILENAME
lStructSize As Long
hwndOwner As Long
hInstance As Long
lpstrFilter As String
lpstrCustomFilter As Long
nMaxCustFilter As Long
nFilterIndex As Long
lpstrFile As String
nMaxFile As Long
lpstrFileTitle As String
nMaxFileTitle As Long
lpstrInitialDir As String
lpstrTitle As String
Flags As Long
nFileOffset As Integer
nFileExtension As Integer
lpstrDefExt As String
lCustData As Long
lpfnHook As Long
lpTemplateName As Long
End Type
Public Type FileDialog
Title As String
CustomFilter As String
DefaultExt As String
InitialDir As String
End Type

‘————————————————-
‘ Costanti a livello domodulo
‘————————————————-
‘usate per l’API GetOpenFileName
Const OFN_READONLY = &H1
Const OFN_OVERWRITEPROMPT = &H2
Const OFN_HIDEREADONLY = &H4
Const OFN_NOCHANGEDIR = &H8
Const OFN_SHOWHELP = &H10
Const OFN_ENABLEHOOK = &H20
Const OFN_ENABLETEMPLATE = &H40
Const OFN_ENABLETEMPLATEHANDLE = &H80
Const OFN_NOVALIDATE = &H100
Const OFN_ALLOWMULTISELECT = &H200
Const OFN_EXTENSIONDIFFERENT = &H400
Const OFN_PATHMUSTEXIST = &H800
Const OFN_FILEMUSTEXIST = &H1000
Const OFN_CREATEPROMPT = &H2000
Const OFN_SHAREAWARE = &H4000
Const OFN_NOREADONLYRETURN = &H8000
Const OFN_NOTESTFILECREATE = &H10000
Const OFN_SHAREFALLTHROUGH = 2
Const OFN_SHARENOWARN = 1
Const OFN_SHAREWARN = 0

‘ DESCRIZIONE:mostra la finestra di dialogo
‘ Apri per il pulsante Sfoglia…

Function WinFileDialog(typOpenDialog As FileDialog, _
iIndex As Integer) As String
Dim OPENFILENAME As OPENFILENAME
Dim Message$, FileName$, FilesDlgTitle
Dim szCurDir$, iReturn As Integer
Dim pathname As String, sAppName As String

‘Alloca spazio per le stringhe restituite.
FileName$ = Chr$(0) & Space$(255) & Chr$(0)
FilesDlgTitle = Chr$(0) & Space$(255) & Chr$(0)

‘Imposta la struttura dei dati prima di GetOpenFileName
With OPENFILENAME
.lStructSize = Len(OPENFILENAME)
.hwndOwner = GetActiveWindow&
.lpstrFilter = typOpenDialog.CustomFilter
.nFilterIndex = 1
.lpstrFile = FileName$
.nMaxFile = Len(FileName$)
.nMaxFileTitle = Len(typOpenDialog.Title)
.lpstrTitle = typOpenDialog.Title
.Flags = OFN_FILEMUSTEXIST Or _
OFN_HIDEREADONLY
.lpstrDefExt = typOpenDialog.DefaultExt
.lpstrInitialDir = typOpenDialog.InitialDir
End With

If iIndex = 1 Then
iReturn = GetOpenFileName(OPENFILENAME)
Else
iReturn = GetSaveFileName(OPENFILENAME)
End If
If iReturn Then
WinFileDialog = Left(OPENFILENAME.lpstrFile, _
InStr(OPENFILENAME.lpstrFile, Chr$(0)) – 1)
End If
End Function

Per avviare la finestra lancio:”ApriExpl”. Buon divertimento.