Browsing for a folder (1.0)
Still using the .NET 1.0 framework and need a "browse for folder" dialog? You'll need to resort to platform invoke (p/invoke) using the Win32 API's. Here's a class that encapsulates all of it.
NOTE: If you're using the .NET 1.1 framework, see the "FolderBrowserDialog" class.
Option Explicit On Option Strict On
Imports System Imports System.Runtime.InteropServices Imports System.Diagnostics Imports System.Text
Public Class FolderBrowser Private Const BFFM_INITIALIZED As Integer = 1 Private Const BFFM_SELCHANGED As Integer = 2 Private Const BFFM_VALIDATEFAILED As Integer = 3 Private Const BFFM_ENABLEOK As Integer = &H465 Private Const BFFM_SETSELECTIONA As Integer = &H466 Private Const BFFM_SETSTATUSTEXT As Integer = &H464
Private Const BIF_RETURNONLYFSDIRS As Short = &H1s Private Const BIF_DONTGOBELOWDOMAIN As Short = &H2s Private Const BIF_STATUSTEXT As Short = &H4s Private Const BIF_RETURNFSANCESTORS As Short = &H8s Private Const BIF_EDITBOX As Short = &H10s Private Const BIF_VALIDATE As Short = &H20s Private Const BIF_USENEWUI As Short = &H40s Private Const BIF_BROWSEFORCOMPUTER As Short = &H1000s Private Const BIF_BROWSEFORPRINTER As Short = &H2000s Private Const BIF_BROWSEINCLUDEFILES As Short = &H4000s
Private Const MAX_PATH As Short = 260
Public Enum START_LOCATION SL_FLAG_CREATE = &H8000 SL_FLAG_DONT_VERIFY = &H4000 SL_ADMINTOOLS = &H30 SL_ALTSTARTUP = &H1D SL_APPDATA = &H1A SL_BITBUCKET = &HA SL_COMMON_ADMINTOOLS = &H2F SL_COMMON_ALTSTARTUP = &H1D SL_COMMON_APPDATA = &H23 SL_COMMON_DESKTOPDIRECTORY = &H19 SL_COMMON_DOCUMENTS = &H2E SL_COMMON_FAVORITES = &H1F SL_COMMON_PROGRAMS = &H17 SL_COMMON_STARTMENU = &H16 SL_COMMON_STARTUP = &H18 SL_COMMON_TEMPLATES = &H2D SL_CONTROLS = &H3 SL_COOKIES = &H21 SL_DESKTOP = &H0 SL_DESKTOPDIRECTORY = &H10 SL_DRIVES = &H11 SL_FAVORITES = &H6 SL_FONTS = &H14 SL_HISTORY = &H22 SL_INTERNET = &H1 SL_INTERNET_CACHE = &H20 SL_LOCAL_APPDATA = &H1C SL_MYPICTURES = &H27 SL_NETHOOD = &H13 SL_NETWORK = &H12 SL_PERSONAL = &H5 SL_PRINTERS = &H4 SL_PRINTHOOD = &H1B SL_PROFILE = &H28 SL_PROGRAM_FILES = &H26 SL_PROGRAM_FILES_COMMON = &H2B SL_PROGRAM_FILES_COMMONX86 = &H2C SL_PROGRAM_FILESX86 = &H2A SL_PROGRAMS = &H2 SL_RECENT = &H8 SL_SENDTO = &H9 SL_STARTMENU = &HB SL_STARTUP = &H7 SL_SYSTEM = &H25 SL_SYSTEMX86 = &H29 SL_TEMPLATES = &H15 SL_WINDOWS = &H24 End Enum
' callback delegate Private Delegate Function BrowseCB(ByVal hWnd As IntPtr, _ ByVal uMsg As Integer, _ ByVal lParam As Integer, _ ByVal lpData As Integer) As Integer
Private Structure BROWSEINFO Dim hOwner As IntPtr Dim pidlRoot As Integer Dim pszDisplayName As String Dim lpszTitle As String Dim ulFlags As Integer Dim lpfn As BrowseCB Dim lParam As IntPtr Dim iImage As Integer End Structure
<DllImport("ole32.dll")> _ Private Shared Sub CoTaskMemFree(ByVal addr As IntPtr) End Sub
<DllImport("user32.dll")> _ Overloads Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal uMsg As Integer, ByVal lParam As Integer, ByVal lpData As Integer) As Integer End Function
<DllImport("user32.dll")> _ Overloads Private Shared Function SendMessage(ByVal hWnd as IntPtr, ByVal uMsg as Integer, ByVal lParam as Integer, ByVal lpData as String) as Integer end function
<DllImport("shell32.dll", CharSet:=CharSet.Ansi)> _ Private Shared Function SHBrowseForFolder(ByRef lpBrowseInfo As BROWSEINFO) As IntPtr End Function
<DllImport("shell32.dll", CharSet:=CharSet.Ansi)> _ Private Shared Function SHGetPathFromIDList(ByVal pidl As IntPtr, ByVal pszPath As StringBuilder) As Integer End Function
<DllImport("shell32.dll", CharSet:=CharSet.Ansi)> _ Private Shared Function SHGetSpecialFolderLocation(ByVal hWnd As IntPtr, ByVal nFolder As Integer, ByRef pidl as Integer) As Integer End Function
Private m_BI As BROWSEINFO Private m_Init as Boolean private m_NewUI As Boolean = False private m_ShowStatus As Boolean = False
Public Sub New(handle as IntPtr) m_BI.hOwner = handle m_BI.lpfn = AddressOf BrowseCallbackProc End Sub
Overloads Public Function Browse() as String m_BI.pidlRoot = 0 Return DoBrowse("") end function
Overloads Public Function Browse(ByVal startPath As String) As String m_BI.pidlRoot = 0 Return DoBrowse(startPath) End Function
Overloads Public Function Browse(ByVal SL As START_LOCATION) As String SHGetSpecialFolderLocation(m_BI.hOwner, SL, m_BI.pidlRoot) Return DoBrowse("") End Function
Private Function DoBrowse(ByVal startPath as String) as String Dim result As IntPtr Dim sel As String
m_BI.ulFlags = BIF_RETURNONLYFSDIRS if m_NewUI then m_BI.ulFlags += BIF_USENEWUI if m_ShowStatus then m_BI.ulFlags += BIF_STATUSTEXT
m_BI.lParam = Marshal.StringToHGlobalAnsi(startPath) m_Init = True result = SHBrowseForFolder(m_BI)
sel = GetFSPath(result)
Call CoTaskMemFree(result)
Return sel End Function
Public Property Title As String Get Return m_BI.lpszTitle End Get Set m_BI.lpszTitle = Value End Set End Property
Public Function BrowseCallbackProc(ByVal hWnd As IntPtr, _ ByVal uMsg As Integer, _ ByVal lParam As Integer, _ ByVal lpData As integer) As Integer if uMsg = BFFM_INITIALIZED then SendMessage(hWnd, BFFM_SETSELECTIONA, 1, lpData) m_Init = False elseif uMsg = BFFM_SELCHANGED and Not m_Init then SendMessage(hWnd, BFFM_SETSTATUSTEXT, 0, GetFSPath(new IntPtr(lParam))) end if End Function
Private Function GetFSPath(ByVal pidl as IntPtr) As String Dim sb As New StringBuilder(MAX_PATH)
If pidl.Equals(IntPtr.Zero) Then Return "" Else If SHGetPathFromIDList(pidl, sb) = 1 Then Return sb.ToString() End If End If End Function
Public Property NewUI As Boolean Get Return m_NewUI End Get Set m_NewUI = Value End Set End Property
Public Property ShowStatus As Boolean Get Return m_ShowStatus End Get Set m_ShowStatus = Value End Set End Property
End Class
Here's some sample code calling the FolderBrowser with various startup options:
Dim oBrowse As FolderBrowser = New FolderBrowser(Me.Handle)
oBrowse.Title = "Title For Browsing"
oBrowse.NewUI = True
oBrowse.ShowStatus = True
Label1.Text = oBrowse.Browse(oBrowse.START_LOCATION.SL_FAVORITES)
Label1.Text = oBrowse.Browse("C:")