I'm trying to obtain the handle of the input box in the chat box of Windows Live Messenger 8.1 and came across Active Accessibility.
After referring to a few threads:
http://forums.fanatic.net.nz/index.php?showtopic=12039
http://shoutbox.menthix.net/showthread.php?tid=51617
http://shoutbox.menthix.net/showthread.php?tid=44...d=460252#pid460252
got the code for VB6 from here:
http://forums.fanatic.net.nz/index.php?showtopic=...hreaded&pid=104508
code:
Private Sub cmdTest_Click()
If lstContacts.SelCount = 0 Then Exit Sub
If lstContacts.Text = "<All>" Then
Else
Dim hwnd As Long
Dim hwnd2 As Long
hwnd = Val(Left(lstContacts.Text, InStr(lstContacts.Text, " - ") - 1))
hwnd2 = FindWindowEx(hwnd, 0, "DirectUIHWND", vbNullString)
Dim lngTMP As IAccessible
Call AccessibleObjectFromWindow(hwnd2, OBJID_CLIENT, IID_IAccessible, lngTMP)
If lngTMP Is Nothing Then
Else
Dim iTMP As IAccessible
Dim lngTMP2 As Long
Set iTMP = lngTMP.accParent
Dim lngCount As Long
lngCount = iTMP.accChildCount
Dim accChildren() As Variant
ReDim accChildren(lngCount - 1)
Call AccessibleChildren(iTMP, 0, lngCount - 1, accChildren(0), lngTMP2)
Dim lngCount2 As Long
For lngCount2 = 0 To lngCount - 1
lstIObjects.AddItem accChildren(lngCount2).accName(CHILDID_SELF) & ":" & accChildren(lngCount2).accValue(CHILDID_SELF)
If accChildren(lngCount2).accName(CHILDID_SELF) = "Input" Then
accChildren(lngCount2).accValue(CHILDID_SELF) = "You see this so you know it's working!"
End If
Next
End If
End If
End Sub
But somehow this code doesn't work with WLM 8.1 so I digged around using the Inspect32 and Accexplorer32 tools from Microsoft Active Accessibility 2.0 SDK, I'm able to make it work by adding the line
code:
On Error Resume Next
at the start of the sub and changing the line
code:
Set iTMP = lngTMP.accParent
to
code:
Set iTMP = lngTMP
However, when I try to translate the code to VB 2005 by using:
code:
Private Declare Function AccessibleObjectFromWindow Lib "oleacc" (ByVal Hwnd As Int32, _
ByVal dwId As Int32, _
ByRef riid As Guid, _
<MarshalAs(UnmanagedType.IUnknown)> ByRef ppvObject As Object) As Int32
Private Declare Function AccessibleChildren Lib "oleacc" (ByVal paccContainer As IAccessible, _
ByVal iChildStart As Integer, _
ByVal cChildren As Integer, _
ByVal rgvarChildren() As Object, _
ByVal pcObtained As Integer) As UInteger
Private Const CHILDID_SELF As Long = 0
Private Const CHILDID_1 As Long = 1
Private Const OBJID_CLIENT As Long = &HFFFFFFFC
code:
Dim hwnd2, hwnd As Integer
Dim windowText As New StringBuilder(255)
hwnd = FindWindowEx(0, 0, "IMWindowClass", vbNullString)
hwnd2 = FindWindowEx(hwnd, 0, "DirectUIHWND", vbNullString)
MsgBox(hwnd2)
Dim lngTMP As Accessibility.IAccessible
Dim ID As Int32 = 0
Dim IID_IAcce As New Guid("618736E0-3C3D-11CF-810C-00AA00389B71")
Call AccessibleObjectFromWindow(hwnd2, OBJID_CLIENT, IID_IAcce, lngTMP)
If lngTMP Is Nothing Then
Else
Dim iTMP As Accessibility.IAccessible
Dim lngTMP2 As Integer
iTMP = lngTMP
Dim lngCount As Integer
lngCount = iTMP.accChildCount
'it's okay up to here
Dim Children(lngCount - 1) As Object
Call AccessibleChildren(iTMP, 0, (lngCount - 1), Children(0), lngTMP2)
MsgBox(lngTMP2.ToString)
Dim lngCount2 As Integer
For lngCount2 = 0 To lngCount - 1
If Children(lngCount2).accName(CHILDID_SELF) = "Input" Then
Children(lngCount2).accValue(CHILDID_SELF) = "You see this so you know it's working!"
End If
Next
End If
I get the error of "System.NullReferenceException" when trying to call "Children(lngCount2)". Upon further checking, I found that the AccessibleChildren function is not returning any value to the variable 'Children' and lngTMP2=0 (it's supposed to be 37). Does that mean the function is not working properly?
Can anybody please point out what's wrong with my code?
Thanks in advance.
