TBBUTTON struct not working with SendMessage
Edit: The originally posted code was in error in assuming that Intptr could be coersed to work across the bitness boundary. That mistake has been corrected.
I have also expanded the tray button data retrieval to retrieve a the button icon if possible. The Code Project article: Shell Tray Info - Arrange your system tray icons was used as the basis for writing this .Net implementation.
Do note that retrieved Icon instances do not own their respective handles as those are still owned by the OS.
The TBBUTTON structure is a bit of pain as fields after fsStyle vary their size based on the OS bitness (32/64). The following works on my system Win 10 (64 bit) for both x86 and x64 compilations. I apologize for the length and apparent formatting (I use 2 char tab stops and SO really messes with the formatting of multiple tabs), but I wish to present all code used in the example.
First is my TBBUTTON declaration. It is defined as base class and a class for 32-bit and class for 64-bit OS. The base class has a factory method (TBBUTTON.CreateForOS) to return the proper implementation. I deal with the varying field sizes by declaring byte place-holders to receive the marshaled structure and re-assemble when needed.
Imports System.Runtime.InteropServices
' Ref: https://docs.microsoft.com/en-us/windows/desktop/api/commctrl/ns-commctrl-tbbutton
' For info on native type size: Windows Data Types
' https://docs.microsoft.com/en-us/windows/desktop/WinProg/windows-data-types
' typedef struct _TBBUTTON {
' int iBitmap;
' int idCommand;
' Byte fsState;
' Byte fsStyle;
' #If ...
' Byte bReserved[6]; - 64 bit
' #Else
' BYTE bReserved[2]; - 32 bit
' #End If
' DWORD_PTR dwData; ' DWORD_PTR = ULONG_PTR 32/64 bits OS=> 4/8 bytes
' INT_PTR iString; ' 32/64 bits OS => 4/8 bytes
' ref: How to Display Tooltips for Buttons
' https://docs.microsoft.com/en-us/windows/desktop/Controls/display-tooltips-for-buttons
' Set the tooltip text as the iString member of the TBBUTTON structure for each button.
' so iString is a pointer to the Tooltip text
' } TBBUTTON, *PTBBUTTON, *LPTBBUTTON;
<StructLayout(LayoutKind.Sequential)>
Friend MustInherit Class TBBUTTON
Public iBitmap As Int32
Public idCommand As Int32
Public fsState As NativeMethods.ToolBars.TBSTATE
Public fsStyle As Byte
Protected bReserved0 As Byte
Protected bReserved1 As Byte
Public Shared ReadOnly Property Is64Bit As Boolean
Get
Return Environment.Is64BitOperatingSystem
End Get
End Property
Public Shared Function CreateForOS() As TBBUTTON
Dim ret As TBBUTTON = Nothing
If AppBitnessMatchesOS() Then
If Environment.Is64BitOperatingSystem Then
ret = New TBBUTTON64
Else
ret = New TBBUTTON32
End If
Else
Throw New Exception($"Application is {If(Environment.Is64BitProcess, 64, 32)} bits and OS is {If(Environment.Is64BitOperatingSystem, 64, 32)}. Bitnesses much match.")
End If
Return ret
End Function
Private Shared Function AppBitnessMatchesOS() As Boolean
Return Environment.Is64BitProcess.Equals(Environment.Is64BitOperatingSystem)
End Function
Public ReadOnly Property MarshalSize As IntPtr
Get
Return New IntPtr(Marshal.SizeOf(Me))
End Get
End Property
Public MustOverride ReadOnly Property Reserved As Byte()
Public MustOverride ReadOnly Property DwData As IntPtr
Public MustOverride ReadOnly Property IString As IntPtr
End Class
<StructLayout(LayoutKind.Sequential)>
Friend NotInheritable Class TBBUTTON32 : Inherits TBBUTTON
Private _dwData As IntPtr
Private _iString As IntPtr
Public Overrides ReadOnly Property Reserved As Byte()
Get
Return New Byte() {bReserved0, bReserved1}
End Get
End Property
Public Overrides ReadOnly Property DwData As IntPtr
Get
Return _dwData
End Get
End Property
Public Overrides ReadOnly Property IString As IntPtr
Get
Return _iString
End Get
End Property
End Class
<StructLayout(LayoutKind.Sequential)>
Friend NotInheritable Class TBBUTTON64 : Inherits TBBUTTON
Protected bReserved2 As Byte
Protected bReserved3 As Byte
Protected bReserved4 As Byte
Protected bReserved5 As Byte
Private _dwData As IntPtr
Private _iString As IntPtr
Public Overrides ReadOnly Property Reserved As Byte()
Get
Return New Byte() {bReserved0, bReserved1, bReserved2, bReserved3, bReserved4, bReserved5}
End Get
End Property
Public Overrides ReadOnly Property DwData As IntPtr
Get
Return _dwData
End Get
End Property
Public Overrides ReadOnly Property IString As IntPtr
Get
Return _iString
End Get
End Property
End Class
Next is my native methods class. This class declares various function overloads to let the interop-marshaling system perform the necessary allocations/conversions.
Imports System.Diagnostics.CodeAnalysis
Imports System.Runtime.ConstrainedExecution
Imports System.Runtime.InteropServices
Imports System.Security
Friend Class NativeMethods
Public Const WM_User As Int32 = &H400
Public Shared Sub FreeHGlobal(ptr As IntPtr)
If ptr <> IntPtr.Zero Then
Marshal.FreeHGlobal(ptr)
End If
End Sub
Public Class ToolBars
#Region "Constants"
' values from CommCtrl.h
''' <summary>Retrieves a count of the buttons currently in the toolbar. </summary>
Public Const TB_BUTTONCOUNT As Int32 = WM_User + 24
Public Const TB_GETBUTTON As Int32 = WM_User + 23
Public Const TB_DELETEBUTTON As Int32 = WM_User + 22
Private Const TB_GETBUTTONINFOW As Int32 = WM_User + 63
Private Const TB_SETBUTTONINFOW As Int32 = WM_User + 64
Private Const TB_GETBUTTONINFOA As Int32 = WM_User + 65
Private Const TB_SETBUTTONINFOA As Int32 = WM_User + 66
''' <summary> The cbSize and dwMask members of this structure must be filled in prior to sending this message.</summary>
Public Const TB_GETBUTTONINFO As Int32 = TB_GETBUTTONINFOW
''' <summary> The cbSize and dwMask members of this structure must be filled in prior to sending this message.</summary>
Public Const TB_SETBUTTONINFO As Int32 = TB_SETBUTTONINFOW
Public Const TB_GETBUTTONTEXTA As Int32 = WM_User + 45
Public Const TB_GETBUTTONTEXTW As Int32 = WM_User + 75
Public Const TB_GETBUTTONTEXT As Int32 = TB_GETBUTTONTEXTW
Public Const TB_GETSTRINGW As Int32 = WM_User + 91
Public Const TB_GETSTRINGA As Int32 = WM_User + 92
''' <summary>This message returns the specified string from the toolbar's string pool. It does not necessarily correspond to the text string currently being displayed by a button.</summary>
Public Const TB_GETSTRING As Int32 = TB_GETSTRINGW
''' <summary>wParam and lParam must be zero. returns handle to the image list, or NULL if no image list is set.</summary>
Public Const TB_GETIMAGELIST As Int32 = WM_User + 49
''' <summary>Retrieves the index of the bitmap associated with a button in a toolbar.
''' wParam=Command identifier of the button whose bitmap index is to be retrieved.</summary>
Public Const TB_GETBITMAP As Int32 = WM_User + 44
<DllImport("comctl32.dll", SetLastError:=True)>
Public Shared Function ImageList_GetIcon(himl As IntPtr, imageIndex As Int32, flags As UInt32) As IntPtr
End Function
<DllImport("comctl32.dll", SetLastError:=True)>
Public Shared Function ImageList_GetImageCount(himl As IntPtr) As Int32
End Function
#End Region
Public Enum TBSTATE As Byte
CHECKED = &H1
PRESSED = &H2
ENABLED = &H4
HIDDEN = &H8
INDETERMINATE = &H10
WRAP = &H20
ELLIPSES = &H40
MARKED = &H80
End Enum
End Class
Public Class User32
#Region "Utility Methods"
Public Shared Function GetNotificationAreaToolBarHandle() As IntPtr
Dim hWndTray As IntPtr = FindWindow("Shell_TrayWnd", Nothing)
If hWndTray <> IntPtr.Zero Then
hWndTray = FindWindowEx(hWndTray, IntPtr.Zero, "TrayNotifyWnd", Nothing)
If hWndTray <> IntPtr.Zero Then
hWndTray = FindWindowEx(hWndTray, IntPtr.Zero, "SysPager", Nothing)
If hWndTray <> IntPtr.Zero Then
hWndTray = FindWindowEx(hWndTray, IntPtr.Zero, "ToolbarWindow32", Nothing)
Return hWndTray
End If
End If
End If
Return IntPtr.Zero
End Function
Public Shared Function GetTaskBarHandle() As IntPtr
Dim hWndTray As IntPtr = FindWindow("Shell_TrayWnd", Nothing)
If hWndTray <> IntPtr.Zero Then
hWndTray = FindWindowEx(hWndTray, IntPtr.Zero, "TrayNotifyWnd", Nothing)
If hWndTray <> IntPtr.Zero Then
'hWndTray = FindWindowEx(hWndTray, IntPtr.Zero, "SysPager", Nothing)
If hWndTray <> IntPtr.Zero Then
'hWndTray = FindWindowEx(hWndTray, IntPtr.Zero, "ToolbarWindow32", Nothing)
End If
End If
End If
Return hWndTray
End Function
#End Region
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)>
Public Shared Function FindWindow(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
End Function
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)>
Public Shared Function FindWindowEx(ByVal hwndParent As IntPtr, ByVal hwndChildAfter As IntPtr, ByVal lpszClass As String, ByVal lpszWindow As String) As IntPtr
End Function
<DllImport("User32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)>
Public Shared Function GetWindowThreadProcessId(ByVal hWnd As IntPtr, <System.Runtime.InteropServices.Out()> ByRef lpdwProcessId As Int32) As Int32
End Function
#Region "SendMessage Overloads"
<DllImport("User32.dll", CharSet:=CharSet.Unicode, EntryPoint:="SendMessage")>
Public Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Int32, ByVal wParam As IntPtr, ByVal lParam As System.Text.StringBuilder) As Int32
End Function
<DllImport("User32.dll", CharSet:=CharSet.Unicode, EntryPoint:="SendMessage")>
Public Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Int32, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
End Function
<DllImport("User32.dll", CharSet:=CharSet.Unicode)>
Public Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Int32, ByVal wParam As Int32, ByVal lParam As Int32) As Int32
End Function
<DllImport("User32.dll", CharSet:=CharSet.Unicode)>
Public Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Int32, ByVal wParam As Int32, ByVal lParam As IntPtr) As Boolean
End Function
#End Region
<StructLayout(LayoutKind.Sequential)>
Friend Structure ICONINFO
''' <summary>Specifies whether this structure defines an icon or a cursor. A value of TRUE specifies an icon; FALSE specifies a cursor.</summary>
Public fIcon As Boolean
''' <summary>Specifies the x-coordinate of a cursor's hot spot. If this structure defines an icon, the hot spot is always in the center of the icon, and this member is ignored.</summary>
Public xHotspot As Int32
''' <summary>Specifies the y-coordinate of the cursor's hot spot. If this structure defines an icon, the hot spot is always in the center of the icon, and this member is ignored.</summary>
Public yHotspot As Int32 '
''' <summary>(HBITMAP) Specifies the icon bitmask bitmap. If this structure defines a black and white icon, this bitmask is formatted so that the upper half is the icon AND bitmask and the lower half is the icon XOR bitmask. Under this condition, the height should be an even multiple of two. If this structure defines a color icon, this mask only defines the AND bitmask of the icon.</summary>
Public hbmMask As IntPtr '
''' <summary>(HBITMAP) Handle to the icon color bitmap. This member can be optional if this structure defines a black and white icon. The AND bitmask of hbmMask is applied with the SRCAND flag to the destination; subsequently, the color bitmap is applied (using XOR) to the estination by using the SRCINVERT flag.</summary>
Public hbmColor As IntPtr
End Structure
<DllImport("user32.dll")>
Shared Function GetIconInfo(ByVal hIcon As IntPtr, ByRef piconinfo As ICONINFO) As Boolean
End Function
End Class
Public Class Kernel32
<DllImport("kernel32.dll", SetLastError:=True)>
<ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)>
<SuppressUnmanagedCodeSecurity>
Public Shared Function CloseHandle(ByVal hObject As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
#Region "OpenProcess"
<DllImport("kernel32.dll", SetLastError:=True)>
Public Shared Function OpenProcess(ByVal processAccess As ProcessAccessFlags, ByVal bInheritHandle As Boolean, ByVal processId As Int32) As IntPtr
End Function
<Flags>
Public Enum ProcessAccessFlags As UInt32
All = &H1F0FFF
Terminate = &H1
CreateThread = &H2
VirtualMemoryOperation = &H8
VirtualMemoryRead = &H10
VirtualMemoryWrite = &H20
DuplicateHandle = &H40
CreateProcess = &H80
SetQuota = &H100
SetInformation = &H200
QueryInformation = &H400
QueryLimitedInformation = &H1000
Synchronize = &H100000
End Enum
#End Region
#Region "ReadProcessMemory Overloads"
<DllImport("kernel32.dll", SetLastError:=True)>
Public Shared Function ReadProcessMemory(
ByVal hProcess As IntPtr,
ByVal lpBaseAddress As IntPtr,
ByVal lpBuffer As IntPtr,
<MarshalAs(UnmanagedType.SysInt)> ByVal iSize As IntPtr,
<MarshalAs(UnmanagedType.SysInt)> ByRef lpNumberOfBytesRead As IntPtr) As Boolean
End Function
<DllImport("kernel32.dll", SetLastError:=True, EntryPoint:="ReadProcessMemory")>
Public Shared Function ReadProcessMemory(
ByVal hProcess As IntPtr,
ByVal lpBaseAddress As IntPtr,
ByRef lpBuffer As Int32,
<MarshalAs(UnmanagedType.SysInt)> ByVal iSize As IntPtr,
<MarshalAs(UnmanagedType.SysInt)> ByRef lpNumberOfBytesRead As IntPtr) As Boolean
End Function
<DllImport("kernel32.dll", SetLastError:=True, EntryPoint:="ReadProcessMemory")>
Public Shared Function ReadProcessMemory(
ByVal hProcess As IntPtr,
ByVal lpBaseAddress As IntPtr,
ByRef lpBuffer As Int64,
<MarshalAs(UnmanagedType.SysInt)> ByVal iSize As IntPtr,
<MarshalAs(UnmanagedType.SysInt)> ByRef lpNumberOfBytesRead As IntPtr) As Boolean
End Function
<DllImport("kernel32.dll", SetLastError:=True, EntryPoint:="ReadProcessMemory")>
Public Shared Function ReadProcessMemory(
ByVal hProcess As IntPtr,
ByVal lpBaseAddress As IntPtr,
ByVal lpBuffer As TBBUTTON,
<MarshalAs(UnmanagedType.SysInt)> ByVal iSize As IntPtr,
<MarshalAs(UnmanagedType.SysInt)> ByRef lpNumberOfBytesRead As IntPtr) As Boolean
End Function
<DllImport("kernel32.dll", SetLastError:=True, EntryPoint:="ReadProcessMemory")>
Public Shared Function ReadProcessMemory(
ByVal hProcess As IntPtr,
ByVal lpBaseAddress As IntPtr,
ByVal lpBuffer As TrayData,
<MarshalAs(UnmanagedType.SysInt)> ByVal iSize As IntPtr,
<MarshalAs(UnmanagedType.SysInt)> ByRef lpNumberOfBytesRead As IntPtr) As Boolean
End Function
#End Region
#Region "VirtualAllocEx"
<DllImport("kernel32.dll", SetLastError:=True, ExactSpelling:=True)>
Shared Function VirtualAllocEx(ByVal hProcess As IntPtr,
ByVal lpAddress As IntPtr,
<MarshalAs(UnmanagedType.SysInt)> ByVal dwSize As IntPtr,
<MarshalAs(UnmanagedType.U4)> ByVal flAllocationType As AllocationType,
ByVal flProtect As MemoryProtection) As IntPtr
End Function
<Flags>
Public Enum AllocationType As UInt32
Commit = &H1000
Reserve = &H2000
Decommit = &H4000
Release = &H8000
Reset = &H80000
Physical = &H400000
TopDown = &H100000
WriteWatch = &H200000
LargePages = &H20000000
End Enum
<Flags>
Public Enum MemoryProtection As UInt32
Execute = &H10
ExecuteRead = &H20
ExecuteReadWrite = &H40
ExecuteWriteCopy = &H80
NoAccess = &H1
[ReadOnly] = &H2
ReadWrite = &H4
WriteCopy = &H8
GuardModifierflag = &H100
NoCacheModifierflag = &H200
WriteCombineModifierflag = &H400
End Enum
#End Region
#Region "VirtualFreeEx"
<DllImport("kernel32.dll")>
Public Shared Function VirtualFreeEx(ByVal hProcess As IntPtr,
ByVal lpAddress As IntPtr,
<MarshalAs(UnmanagedType.SysInt)> ByVal dwSize As IntPtr,
ByVal dwFreeType As FreeType) As Boolean
End Function
''' <summary>helper method to release memory allocated with VirtualAllocEx</summary>
''' <param name="lpAddress">ptr received from VirtualAllocEx</param>
''' <param name="hProcess">ptr to process received from OpenProcess</param>
Public Shared Sub ReleaseVirtualAlloc(ByRef lpAddress As IntPtr, hProcess As IntPtr)
If lpAddress <> IntPtr.Zero Then
VirtualFreeEx(hProcess, lpAddress, Nothing, FreeType.RELEASE)
lpAddress = IntPtr.Zero
End If
End Sub
<Flags()>
Public Enum FreeType As UInt32
DECOMMIT = &H4000
RELEASE = &H8000
End Enum
#End Region
End Class
End Class
There are two additional support classes defined below.
Friend Class TrayButtonInfo
Public Property Icon As Icon
Public Property Index As Int32
Public Property CommandID As Int32
Public Property DisplayText As String = String.Empty
Public Property ProcessFound As Boolean = False
Public Property ProcessName As String = String.Empty
Public Property ProcessID As Int32
Public Property State As NativeMethods.ToolBars.TBSTATE
End Class
...
Imports System.Runtime.InteropServices
<StructLayout(LayoutKind.Sequential)>
Friend Class TrayData
Public hWnd As IntPtr
Public uID As Int32
Public uCallbackMessage As UInt32
Public Reservered0 As UInt32
Public Reservered1 As UInt32
Public hIcon As IntPtr
Public ReadOnly Property OwningProcess As Process
Get
Dim ret As Process = Nothing
If hWnd <> IntPtr.Zero Then
Dim processIDOfButton As Int32
Dim threadId As Int32 = NativeMethods.User32.GetWindowThreadProcessId(hWnd, processIDOfButton)
Try ' Process.GetProcessById can throw an exception if the id is not found
ret = Process.GetProcessById(processIDOfButton)
Catch ex As Exception
' eat it
End Try
End If
Return ret
End Get
End Property
End Class
Now for the actual example code. This code prepare a list of TrayButtonInfo instances that can be searched to find a matching button. It also shows an example of this search and how to delete the button. I tried to explain the code in the comments, but feel free to ask about anything that is not clear.
Imports System.Runtime.InteropServices
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim retrievedNotificationButtons As List(Of TrayButtonInfo) = PrepareButtonInfoList()
' Now we have filled retrievedNotificationButtons with the information for all the buttons
' "Realtek HD Audio Manager" is just for testing on my machine.
' apply criteria for finding the button you want to delete
' note that the button can be restored by restarting Explorer
Dim targetBtn As TrayButtonInfo = retrievedNotificationButtons.FirstOrDefault(Function(info) info.DisplayText.StartsWith("Realtek HD Audio Manager"))
If targetBtn IsNot Nothing Then ' delete the button
' the following statement will delete the button if uncommented
'Dim toolBarHwnd As IntPtr = NativeMethods.User32.GetNotificationAreaToolBarHandle()
'NativeMethods.User32.SendMessage(toolBarHwnd, NativeMethods.ToolBars.TB_DELETEBUTTON, targetBtn.Index, 0)
End If
DataGridView1.DataSource = retrievedNotificationButtons
End Sub
Private Function PrepareButtonInfoList() As List(Of TrayButtonInfo)
Dim ret As List(Of TrayButtonInfo)
' create a TBButon structure appropriate for the OS bitness
Dim btn As TBBUTTON = TBBUTTON.CreateForOS
Dim toolBarProcessHandle As IntPtr
Dim toolBarButtonProcessMemoryPtr As IntPtr
' obtain window handle of the notification area toolbar
Dim toolBarHwnd As IntPtr = NativeMethods.User32.GetNotificationAreaToolBarHandle()
' obtain id of process that owns the notification area toolbar, threadId is of no consequence
Dim proccessIDOwningToolBar As Int32
Dim threadId As Int32 = NativeMethods.User32.GetWindowThreadProcessId(toolBarHwnd, proccessIDOwningToolBar)
Try
' obtain handle to the toolbar process that will allow allocating,reading and writing
toolBarProcessHandle = NativeMethods.Kernel32.OpenProcess(NativeMethods.Kernel32.ProcessAccessFlags.VirtualMemoryOperation Or
NativeMethods.Kernel32.ProcessAccessFlags.VirtualMemoryRead Or
NativeMethods.Kernel32.ProcessAccessFlags.VirtualMemoryWrite,
False, proccessIDOwningToolBar)
' allocate memory in the toolbar process to hold the TBButton
' need ReadWrite access due to TB_GETBUTTON writing to the allocated memory
toolBarButtonProcessMemoryPtr = NativeMethods.Kernel32.VirtualAllocEx(toolBarProcessHandle,
Nothing,
btn.MarshalSize,
NativeMethods.Kernel32.AllocationType.Commit,
NativeMethods.Kernel32.MemoryProtection.ReadWrite)
' now we can request the toolbar to fill the allocated memory with a TBButton structure
' for each button in the notifiaction area.
' determine how many toolbar buttons are visible notification area contains
Dim buttonCount As Int32 = NativeMethods.User32.SendMessage(toolBarHwnd, NativeMethods.ToolBars.TB_BUTTONCOUNT, 0, 0)
ret = New List(Of TrayButtonInfo)(buttonCount)
For btnIndex As Int32 = 0 To buttonCount - 1
Dim btnInfo As New TrayButtonInfo With {.Index = btnIndex}
ret.Add(btnInfo)
If NativeMethods.User32.SendMessage(toolBarHwnd, NativeMethods.ToolBars.TB_GETBUTTON, btnIndex, toolBarButtonProcessMemoryPtr) Then
' the toolbar owning process has successfully filled toolBarButtonProcessMemoryPtr
' use a customize ReadProcessMemory that takes a TBButtonBase instance as the destination buffer
If NativeMethods.Kernel32.ReadProcessMemory(toolBarProcessHandle, toolBarButtonProcessMemoryPtr, btn, btn.MarshalSize, Nothing) Then
' btn has been loaded, get the data
btnInfo.CommandID = btn.idCommand
btnInfo.State = btn.fsState
' Note that per the documentation, TBBUTTON.iString can contain a pointer the Tooltip Text
' In testing it does, but I have not found out how to determine the length of the string
' without the length, a guess on the size of process memory to read must be made and that
' seems unwise when accessing memory.
' GetButtonText use the TB_GETBUTTONTEXT message. This message's documentation indicates
' that the retrieved text may differ from the Tooltip text. As Tooltip text can be provided
' via several mechanisms, this makes sense.
btnInfo.DisplayText = GetButtonText(btnInfo.CommandID, toolBarHwnd, toolBarProcessHandle)
' get the process pointed to by dwData
' according to: Code Project article: A tool to order the window buttons in your taskbar
' https://www.codeproject.com/Articles/10497/A-tool-to-order-the-window-buttons-in-your-taskbar
' this is a pointer to the window handle of the process that owns the button
' while I can find no documentation that this is true, it appears to work
GetButtonData(btn, toolBarProcessHandle, btnInfo)
End If ' ReadProcessMemoryToTBButton
End If
Next
Finally ' cleanup handles
If toolBarProcessHandle <> IntPtr.Zero Then
NativeMethods.Kernel32.ReleaseVirtualAlloc(toolBarButtonProcessMemoryPtr, toolBarProcessHandle)
End If
If toolBarProcessHandle <> IntPtr.Zero Then
NativeMethods.Kernel32.CloseHandle(toolBarProcessHandle)
toolBarProcessHandle = IntPtr.Zero
End If
End Try
Return ret
End Function
Private Function GetButtonText(CommandID As Int32, toolBarWindowHandle As IntPtr, toolBarProcessHandle As IntPtr) As String
Dim ret As String = String.Empty
'1st determine the number of characters to retrieve
Dim lenText As Int32 = NativeMethods.User32.SendMessage(toolBarWindowHandle, NativeMethods.ToolBars.TB_GETBUTTONTEXT, New IntPtr(CommandID), IntPtr.Zero).ToInt32
If lenText > 0 Then
Dim ptrToText As IntPtr
Dim localBuffer As IntPtr
Try
Dim numBytes As New IntPtr((lenText * 2) + 1) ' Unicode 2 bytes per character + 1 for null terminator
'need to allocate the string in the process space
ptrToText = NativeMethods.Kernel32.VirtualAllocEx(toolBarProcessHandle,
Nothing,
numBytes,
NativeMethods.Kernel32.AllocationType.Commit,
NativeMethods.Kernel32.MemoryProtection.ReadWrite)
Dim receivedLen As Int32 = NativeMethods.User32.SendMessage(toolBarWindowHandle, NativeMethods.ToolBars.TB_GETBUTTONTEXT, New IntPtr(CommandID), ptrToText).ToInt32
localBuffer = Marshal.AllocHGlobal(numBytes) ' allocate local buffer to receive bytes from process space
If NativeMethods.Kernel32.ReadProcessMemory(toolBarProcessHandle, ptrToText, localBuffer, numBytes, Nothing) Then
ret = Marshal.PtrToStringUni(localBuffer)
End If
Finally ' release handles to unmanaged memory
NativeMethods.Kernel32.ReleaseVirtualAlloc(ptrToText, toolBarProcessHandle)
NativeMethods.FreeHGlobal(localBuffer)
End Try
End If
Return ret
End Function
Private Sub GetButtonData(btn As TBBUTTON, toolBarProcessHandle As IntPtr, btnInfo As TrayButtonInfo)
Dim data As TrayData
Try
data = New TrayData()
Dim dataMarshalSize As New IntPtr(Marshal.SizeOf(data))
If NativeMethods.Kernel32.ReadProcessMemory(toolBarProcessHandle, btn.DwData, data, dataMarshalSize, Nothing) Then
' use GetIconInfo to validate icon handle
Dim iconInfo As New NativeMethods.User32.ICONINFO
If NativeMethods.User32.GetIconInfo(data.hIcon, iconInfo) Then
btnInfo.Icon = Icon.FromHandle(data.hIcon)
End If
Using p As Process = data.OwningProcess
If p IsNot Nothing Then
btnInfo.ProcessFound = True
btnInfo.ProcessID = p.Id
btnInfo.ProcessName = p.ProcessName
End If
End Using
End If
Catch ex As Exception
Debug.Print(ex.Message)
End Try
End Sub
End Class
One thing that I observed in limited testing is that intermitantly, addition characters are post-pended onto the retrieved button text. I tried zeroing the memory but that did not help. Hence the use of the StartsWith when searching for a target button to delete.