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| Visual Basic
Hook Routines GetOpenFileName: Set an Open/Save Dialog's Initial Listview View |
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| Posted: | Monday July 26, 2004 | |
| Updated: | Monday December 26, 2011 | |
| Applies to: | VB5, VB6 | |
| Developed with: | VB6, Windows XP | |
| OS restrictions: | None | |
| Author: | Brad Martinez, VBnet - Randy Birch | |
| Related: | GetOpenFileName: File Open/Save Common Dialog API - Overview GetSaveFileName: File Save Common Dialog Basics GetOpenFileName: File Open Common Dialog Basics GetOpenFileName: Advanced Dialog Centering using a Callback GetOpenFileName: Customize File Open/Save Common Dialog Controls |
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| Prerequisites |
| None. |
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Using
a hook it is possible to send a message to the listview within an Open or
Save dialog created using the Common Dialog APIs to set the initial
display state of the listview control to that other than the default
"list" view. This demo contains the code required to do this, including
code to determine the operating system through which the proper
OPENFILENAME structure is used for a given OS version, providing users of
Windows 2000 or later to view the dialog with the Places Bar presented.
The code also shows setting the OFN_EX_NOPLACESBAR flag to suppress the
Places Bar display. On pre-Win2000 systems, the No Places Bar checkbox is
disabled.
The initial call in the Command1_Click routine calls the SetOSVersion routine to assign the proper OPENFILENAME structure length to a work variable used to complete the ofn.nStructSize member. The illustrations cycling below shows the effect of the selection made in the demo. Although the demo does not show calling the Save dialog, the methodology is identical.
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| BAS Module Code |
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| Place the following code into the general declarations area of a bas module: |
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Option Explicit '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ' Copyright ©1996-2011 VBnet/Randy Birch, All Rights Reserved. ' Some pages may also contain other copyrights by the author. '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ' Distribution: You can freely use this code in your own ' applications, but you may not reproduce ' or publish this code on any web site, ' online service, or distribute as source ' on any media without express permission. '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' 'var for exposed property
Private m_lvInitialView As Long
'windows version constants
Private Const VER_PLATFORM_WIN32_NT As Long = 2
Private Const OSV_LENGTH As Long = 76
Private Const OSVEX_LENGTH As Long = 88
Public OSV_VERSION_LENGTH As Long 'our const to hold appropriate OSV length
Private Type OSVERSIONINFO
OSVSize As Long
dwVerMajor As Long
dwVerMinor As Long
dwBuildNumber As Long
PlatformID As Long
szCSDVersion As String * 128
End Type
'windows messages & notifications etc
Private Const WM_COMMAND = &H111
Public Const WM_NOTIFY As Long = &H4E&
Public Const WM_INITDIALOG As Long = &H110
Public Const CDN_FIRST As Long = -601
Public Const CDN_INITDONE As Long = (CDN_FIRST - &H0&)
Public Const MAX_PATH As Long = 260
'openfilename constants
Public Const OFN_ENABLEHOOK As Long = &H20
Public Const OFN_EXPLORER As Long = &H80000
Public Const OFN_ENABLESIZING As Long = &H800000
Public Const OFN_EX_NOPLACESBAR As Long = &H1
'constants for listview view state
'provided by Brad Martinez
Public Const SHVIEW_ICON As Long = &H7029
Public Const SHVIEW_LIST As Long = &H702B
Public Const SHVIEW_REPORT As Long = &H702C
Public Const SHVIEW_THUMBNAIL As Long = &H702D
Public Const SHVIEW_TILE As Long = &H702E
'this is the version 5+ definition of
'the OPENFILENAME structure containing
'three additional members providing
'additional options on Windows 2000
'or later. The SetOSVersion routine
'will assign either OSV_LENGTH (76)
'or OSVEX_LENGTH (88) to the OSV_VERSION_LENGTH
'variable declared above. This variable, rather
'than Len(OFN) is used to assign the required
'value to the OPENFILENAME structure's nStructSize
'member which tells the OS if extended features
'- primarily the Places Bar - are supported.
Public Type OPENFILENAME
nStructSize As Long
hwndOwner As Long
hInstance As Long
sFilter As String
sCustomFilter As String
nMaxCustFilter As Long
nFilterIndex As Long
sFile As String
nMaxFile As Long
sFileTitle As String
nMaxTitle As Long
sInitialDir As String
sDialogTitle As String
flags As Long
nFileOffset As Integer
nFileExtension As Integer
sDefFileExt As String
nCustData As Long
fnHook As Long
sTemplateName As String
pvReserved As Long
dwReserved As Long
flagsEx As Long
End Type
Public OFN As OPENFILENAME
'defined As Any to support either the
'OSVERSIONINFO or OSVERSIONINFOEX structure
Private Declare Function GetVersionEx Lib "kernel32" _
Alias "GetVersionExA" _
(lpVersionInformation As Any) As Long
Public Declare Function GetOpenFileName Lib "comdlg32.dll" _
Alias "GetOpenFileNameA" _
(pOpenfilename As OPENFILENAME) As Long
Private Declare Function FindWindowEx Lib "user32" _
Alias "FindWindowExA" _
(ByVal hWndParent As Long, _
ByVal hWndChildAfter As Long, _
ByVal lpClassName As String, _
ByVal lpWindowName As String) As Long
Private Declare Function GetParent Lib "user32" _
(ByVal hwnd As Long) As Long
Private Declare Function SendMessage Lib "user32" _
Alias "SendMessageA" _
(ByVal hwnd As Long, _
ByVal wMsg As Long, _
ByVal wParam As Long, _
lParam As Any) As Long
Public Function FARPROC(pfn As Long) As Long
'A dummy procedure that receives and returns
'the return value of the AddressOf operator.
'Obtain and set the address of the callback
'This workaround is needed as you can't assign
'AddressOf directly to a member of a user-
'defined type, but you can assign it to another
'long and use that (as returned here)
FARPROC = pfn
End Function
Public Function IsWin2000Plus() As Boolean
'returns True if running Windows 2000 or later
Dim osv As OSVERSIONINFO
osv.OSVSize = Len(osv)
If GetVersionEx(osv) = 1 Then
IsWin2000Plus = (osv.PlatformID = VER_PLATFORM_WIN32_NT) And _
(osv.dwVerMajor = 5 And osv.dwVerMinor >= 0)
End If
End Function
Public Property Let OFN_SetInitialView(ByVal initview As Long)
m_lvInitialView = initview
End Property
Public Function OFNHookProc(ByVal hwnd As Long, _
ByVal uMsg As Long, _
ByVal wParam As Long, _
ByVal lParam As Long) As Long
Dim hWndParent As Long
Dim hwndLv As Long
Static bLvSetupDone As Boolean
Select Case uMsg
Case WM_INITDIALOG
'Initdialog is set when the dialog
'has been created and is ready to
'be displayed, so set our flag
'to prevent re-executing the code
'in the wm_notify message. This is
'required as the dialog receives a
'number of WM_NOTIFY messages throughout
'the life of the dialog. If this is not
'done, and the user chooses a different
'view, on the next WM_NOTIFY message
'the listview would be reset to the
'initial view, probably ticking off
'the user. The variable is declared
'static to preserve values between
'calls; it will be automatically reset
'on subsequent showing of the dialog.
bLvSetupDone = False
'other WM_INITDIALOG code here, such
'as caption or button changing, or
'centering the dialog.
Case WM_NOTIFY
If bLvSetupDone = False Then
'hwnd is the handle to the dialog
'hwndParent is the handle to the common control
'hwndLv is the handle to the listview itself
hWndParent = GetParent(hwnd)
hwndLv = FindWindowEx(hWndParent, 0, "SHELLDLL_DefView", vbNullChar)
If hwndLv > 0 Then
Call SendMessage(hwndLv, WM_COMMAND, ByVal m_lvInitialView, ByVal 0&)
'since we found the lv hwnd, assume the
'command was received and set the flag
'to prevent recalling this routine
bLvSetupDone = True
End If 'hwndLv
End If 'bLvSetupDone
Case Else
End Select
End Function
Public Sub SetOSVersion()
Select Case IsWin2000Plus()
Case True
OSV_VERSION_LENGTH = OSVEX_LENGTH '5.0+ structure size
Case Else
OSV_VERSION_LENGTH = OSV_LENGTH 'pre-5.0 structure size
End Select
End Sub |
| Form Code |
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| To form containing a list box, check box and command button with the default names add the following code: |
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Option Explicit Private Sub Form_Load()
Command1.Caption = "Get File Open"
With Check1
.Caption = "No Places Bar"
.Enabled = IsWin2000Plus()
End With
With List1
.AddItem "Thumbnails"
.ItemData(.NewIndex) = SHVIEW_THUMBNAIL
.AddItem "Tiles"
.ItemData(.NewIndex) = SHVIEW_TILE
.AddItem "Icon (Large)"
.ItemData(.NewIndex) = SHVIEW_ICON
.AddItem "List (default view)"
.ItemData(.NewIndex) = SHVIEW_LIST
.AddItem "Details (Report view)"
.ItemData(.NewIndex) = SHVIEW_REPORT
.ListIndex = 3 'list view, the default view
End With
End Sub
Private Sub Command1_Click()
Dim sFilters As String
Dim OFN As OPENFILENAME
If OSV_VERSION_LENGTH = 0 Then SetOSVersion
'filters for the dialog
sFilters = "All Files" & vbNullChar & "*.*" & vbNullChar & vbNullChar
'populate the structure
With OFN
.nStructSize = OSV_VERSION_LENGTH
.hwndOwner = Form1.hwnd
.sFilter = sFilters
.nFilterIndex = 0
.sFile = vbNullChar & Space$(MAX_PATH) & vbNullChar & vbNullChar
.nMaxFile = Len(.sFile)
.sDefFileExt = "*.*" & vbNullChar & vbNullChar
.sFileTitle = vbNullChar & Space$(512) & vbNullChar & vbNullChar
.nMaxTitle = Len(OFN.sFileTitle)
.sInitialDir = "D:\Graphics\vbgfx\icons\Downloads 5" & vbNullChar & vbNullChar
.sDialogTitle = "VBnet GetOpenFileName Demo"
.flags = OFN_EXPLORER Or OFN_ENABLEHOOK Or OFN_ENABLESIZING
If Check1.Value = vbChecked Then
.flagsEx = OFN_EX_NOPLACESBAR
End If
.fnHook = FARPROC(AddressOf OFNHookProc)
End With
'call the API.(See the other demos for
'how to retrieve selected file(s) info
'from the dialog.)
Call GetOpenFileName(OFN)
End Sub
Private Sub List1_Click()
With List1
If .ListIndex > -1 Then
OFN_SetInitialView = .ItemData(.ListIndex)
End If
End With
End Sub |
| Comments |
| For a discussion on modifying the OPENFILENAME structure in order to display the new Windows 2000 or Windows XP-style Open and Save dialogs, please see the comments section in the page GetOpenFileName: File Dialog Centering using a Callback. |
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Copyright ©1996-2011 VBnet and Randy Birch. All Rights Reserved. |
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