Hi Peter,
Sorry, but I don't understand this bit at all:
'recursive
nTmp = FindWindowHwndLike(hwnd, ClassName, WindowTitle, level)
If nTmp Then nResult = nTmp
'then finally -
FindWindowHwndLike = nResult
Exit function
How and where are nTmp and nResult declared?
Why would it make a difference?
I tried something like you suggested, but still get zero.
What I don't understand is this: It finds the right window, with the right
hwnd, but it returns zero.
Where does the variable hwnd change from the right value to zero?
I put messageboxes in the recursive function that could show after the right
window was found, but nil of these show, so no code runs after the window
was found:
Function FindWindowHwndLike(ByVal hWndStart As Long, _
ByVal ClassName As String, _
ByVal WindowTitle As String, _
ByVal level As Long) As Long
'finds the first window where the class name start with ClassName
'and where the Window title starts with WindowTitle, returns Hwnd
'-----------------------------------------------------------------
Dim hwnd As Long
Dim sWindowTitle As String
Dim sClassName As String
Dim r As Long
Dim bFound As Boolean
If bFound Then
MsgBox "test1"
End If
'Initialize if necessary. This is only executed
'when level = 0 and hWndStart = 0, normally
'only on the first call to the routine.
If level = 0 Then
If hWndStart = 0 Then
hWndStart = GetDesktopWindow()
End If
End If
'Increase recursion counter
level = level + 1
'Get first child window
hwnd = GetWindow(hWndStart, GW_CHILD)
If bFound Then
MsgBox "test2"
End If
Do Until hwnd = 0
If bFound Then
MsgBox "test3"
End If
'Search children by recursion
FindWindowHwndLike hwnd, ClassName, WindowTitle, level
'Get the window text
sWindowTitle = Space$(255)
r = GetWindowText(hwnd, sWindowTitle, 255)
sWindowTitle = Left$(sWindowTitle, r)
'get the class name
sClassName = Space$(255)
r = GetClassName(hwnd, sClassName, 255)
sClassName = Left$(sClassName, r)
'Check if the window matches the search parameters
If (sWindowTitle Like "*" & WindowTitle & "*") And _
(sClassName Like ClassName & "*") Then
If bFound Then
MsgBox "test4"
End If
bFound = True
MsgBox hwnd
FindWindowHwndLike = hwnd
Exit Function
If bFound Then
MsgBox "test5"
End If
End If
If bFound Then
MsgBox "test6"
End If
'Get next child window
hwnd = GetWindow(hwnd, GW_HWNDNEXT)
If bFound Then
MsgBox "test7"
End If
Loop
If bFound Then
MsgBox "test8"
End If
End Function
The trouble probably is that recursive function are bit mind-boggling in any
case and I might be overlooking something simple here.
I just know that in my particular situation I don't have to worry about more
than one qualifying windows.
Thanks in any case for your suggestions.
RBS
"Peter T" <peter_t@discussions wrote in message
...
Hi Bart,
My take is the function return value persists only in the calling stack.
So two solutions, the first as you've described and include an additional
ByRef arg to return the value all the way back to the original calling
routine. Or something like this:
'recursive
nTmp = FindWindowHwndLike(hwnd, ClassName, WindowTitle, level)
If nTmp Then nResult = nTmp
'then finally -
FindWindowHwndLike = nResult
Exit function
I think passing the additional ByRef arg would be faster.
Just a thought, maybe build an array of all the "like" window captions,
just
in case more than one.
Regards,
Peter T
"RB Smissaert" wrote in message
...
Have a recursive function that returns the window handle of a particular
window, based on the window type and text.
It works fine and it finds the right window, but it just doesn't return
the
right value. It returns zero.
When I do a msgbox before the Exit function it shows fine, or when I
retrieve the value with a private variable I get the right value as well.
It
is not a problem, but just wondering why this happens.
Option Explicit
Private Declare Function GetDesktopWindow Lib "user32" () As Long
Private Declare Function GetWindow Lib "user32" _
(ByVal hwnd As Long, _
ByVal wCmd As Long) As Long
Private Declare Function GetWindowText Lib "user32" _
Alias "GetWindowTextA" _
(ByVal hwnd As Long, _
ByVal lpString As String, _
ByVal cch As Long) As Long
Private Declare Function GetClassName Lib "user32" _
Alias "GetClassNameA" _
(ByVal hwnd As Long, _
ByVal lpClassName As String, _
ByVal nMaxCount As Long) As Long
Private Const GW_HWNDFIRST = 0
Private Const GW_HWNDLAST = 1
Private Const GW_HWNDNEXT = 2
Private Const GW_HWNDPREV = 3
Private Const GW_OWNER = 4
Private Const GW_CHILD = 5
Sub tester()
MsgBox FindWindowHwndLike(0, "Static", "DOB", 0)
End Sub
Function FindWindowHwndLike(ByVal hWndStart As Long, _
ByVal ClassName As String, _
ByVal WindowTitle As String, _
ByVal level As Long) As Long
'finds the first window where the class name start with ClassName
'and where the Window title starts with WindowTitle, returns Hwnd
'-----------------------------------------------------------------
Dim hwnd As Long
Dim sWindowTitle As String
Dim sClassName As String
Dim r As Long
'Initialize if necessary. This is only executed
'when level = 0 and hWndStart = 0, normally
'only on the first call to the routine.
If level = 0 Then
If hWndStart = 0 Then
hWndStart = GetDesktopWindow()
End If
End If
'Increase recursion counter
level = level + 1
'Get first child window
hwnd = GetWindow(hWndStart, GW_CHILD)
Do Until hwnd = 0
'Search children by recursion
Call FindWindowHwndLike(hwnd, ClassName, WindowTitle, level)
'Get the window text
sWindowTitle = Space$(255)
r = GetWindowText(hwnd, sWindowTitle, 255)
sWindowTitle = Left$(sWindowTitle, r)
'get the class name
sClassName = Space$(255)
r = GetClassName(hwnd, sClassName, 255)
sClassName = Left$(sClassName, r)
'Check if the window matches the search parameters
If (sWindowTitle Like "*" & WindowTitle & "*") And _
(sClassName Like ClassName & "*") Then
FindWindowHwndLike = hwnd
Exit Function
End If
'Get next child window
hwnd = GetWindow(hwnd, GW_HWNDNEXT)
Loop
End Function
Thanks for any advice.
RBS