[RESOLVED] Get TaskBar button text

[bushmobile]

I'm trying to get the taskbar button ID for my App. I only need to do this once, so I figured I'd just loop through buttons, get the caption and compare it to my app's caption. I'm using TB_GETBUTTONTEXT to get the captions, but whilst its returning the length of the caption, it's not populating the buffer.

Here's the code:

Public Declare Function FindWindow Lib "user32" Alias "FindWindowA" ( _
    ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Public Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" ( _
    ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long
Public 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 Const WM_USER = &H400
Public Const TB_GETBUTTONTEXT = (WM_USER + 45)
 
Public Function GetAppsID(ByVal sCaption As String) As Long
    Dim lhWnd As Long, N As Long, lLen As Long, sBuff As String
    lhWnd = FindWindow("Shell_TrayWnd", vbNullString)
    lhWnd = FindWindowEx(lhWnd, 0&, "ReBarWindow32", vbNullString)
    lhWnd = FindWindowEx(lhWnd, 0&, "MSTaskSwWClass", vbNullString)
    lhWnd = FindWindowEx(lhWnd, 0&, "ToolbarWindow32", vbNullString)
    
    Do
        lLen = SendMessage(lhWnd, TB_GETBUTTONTEXT, N, Null)
        If lLen = -1 Then Exit Do
        sBuff = Space$(lLen + 1)
        lLen = SendMessage(lhWnd, TB_GETBUTTONTEXT, N, sBuff)
        Debug.Print N, lLen, Trim$(sBuff)
        N = N + 1
    Loop Until N = 50
End Function

Any ideas?

be warned: passing the lParam ByVal causes an error in explorer.

[Agilaz]

i think you need to use OpenProcess and to allocate some memory for the buffer in the target app (explorer) for this to work. then use SendMessage with a pointer to that buffer and ReadProcessMemory to get the text. and don't forget to free the buffer and close the process when you're done.

[bushmobile]

yeah, that's what thought - ah well, bit annoying.

Here's the code for anyone interested:

' General
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
    
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" ( _
    ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long
    
' Process And Memory
Private Declare Function GetWindowThreadProcessId Lib "user32" ( _
    ByVal hWnd As Long, lpdwProcessId As Long) As Long
    
Private Declare Function OpenProcess Lib "kernel32" ( _
    ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long
    
Private Declare Function CloseHandle Lib "kernel32" ( _
    ByVal hObject As Long) As Long
    
Private Declare Function VirtualFreeEx Lib "kernel32" ( _
    ByVal hProcess As Long, lpAddress As Any, ByRef dwSize As Long, ByVal dwFreeType As Long) As Long
    
Private Declare Function VirtualAllocEx Lib "kernel32" ( _
    ByVal hProcess As Long, lpAddress As Any, ByRef dwSize As Long, ByVal flAllocationType As Long, _
    ByVal flProtect As Long) As Long
    
Private Declare Function ReadProcessMemory Lib "kernel32" ( _
    ByVal hProcess As Long, lpBaseAddress As Any, lpBuffer As Any, ByVal nSize As Long, _
    Optional lpNumberOfBytesWritten As Long) As Long
 
Const PROCESS_VM_READ = (&H10)
Const PROCESS_VM_WRITE = (&H20)
Const PROCESS_VM_OPERATION = (&H8)
Const MEM_COMMIT = &H1000
Const MEM_RESERVE = &H2000
Const MEM_RELEASE = &H8000
Const PAGE_READWRITE = &H4
 
Const WM_USER = &H400
Const TB_ISBUTTONHIDDEN = (WM_USER + 12)
Const TB_BUTTONCOUNT = (WM_USER + 24)
Const TB_GETBUTTONTEXTA = (WM_USER + 45)
 
Private Sub Form_Load()
    Dim hTaskBar As Long, pID As Long, hProcess As Long
    Dim N As Long, lCount As Long, lNum As Long, lLen As Long
    Dim sCaption As String * 128, lpCaption As Long
    
    Me.Show
    
    hTaskBar = GetNotificationWindow
    GetWindowThreadProcessId hTaskBar, pID
    hProcess = OpenProcess(PROCESS_VM_READ Or PROCESS_VM_WRITE Or PROCESS_VM_OPERATION, 0, pID)
    
    lpCaption = VirtualAllocEx(hProcess, ByVal 0&, Len(sCaption), MEM_COMMIT Or MEM_RESERVE, PAGE_READWRITE)
    lNum = SendMessage(hTaskBar, TB_BUTTONCOUNT, 0, ByVal 0&)
    
    Do Until lCount = lNum
        lLen = SendMessage(hTaskBar, TB_GETBUTTONTEXTA, N, ByVal lpCaption)
        If lLen > -1 Then
            If SendMessage(hTaskBar, TB_ISBUTTONHIDDEN, N, 0&) = 0 Then
                ReadProcessMemory hProcess, ByVal lpCaption, ByVal sCaption, Len(sCaption)
                Debug.Print Left$(sCaption, InStr(sCaption, vbNullChar) - 1)
            End If
            lCount = lCount + 1
        End If
        N = N + 1
    Loop
        
    VirtualFreeEx 0, lpCaption, 0, MEM_RELEASE
    CloseHandle hProcess
End Sub
 
Private Function GetNotificationWindow() As Long
    Dim lhWnd As Long
    lhWnd = FindWindowEx(0&, 0&, "Shell_TrayWnd", vbNullString)
    lhWnd = FindWindowEx(lhWnd, 0&, "ReBarWindow32", vbNullString)
    lhWnd = FindWindowEx(lhWnd, 0&, "MSTaskSwWClass", vbNullString)
    GetNotificationWindow = FindWindowEx(lhWnd, 0&, "ToolbarWindow32", vbNullString)
End Function

modified from this code for getting the processes running in the SysTray.

[iPrank]

Ha Ha ! I was trying with the same code, too.

BTW, looks like for every window, Explorer creates a hidden button. Any light on this ?

[bushmobile]

BTW, looks like for every window, Explorer creates a hidden button.

it's because of grouping (even if you haven't got it enabled) - so that it can collate the buttons.

[iPrank]

I hate XP.
2K Pro was the best OS, IMO.