Re: API Class Question

Thank you very much for your reply. I think I understand where you're
going with this, but I can't seem to get it working. When I add in
the FARPROC function and use it per your example, I'm still getting
the same error that I originally described:

Call EnumWindows(FARPROC(AddressOf GetOpenWindows), VarPtr(tParms))




On Oct 30, 9:45 am, "RB Smissaert" <bartsmissa...@xxxxxxxxxxxxxxxx>
wrote:
I forgot to give an example:

With CC
'base flag
.flags = CC_ANYCOLOR
.flags = .flags Or CC_FULLOPEN
.flags = .flags Or CC_RGBINIT
.rgbResult = lStartColour
.flags = .flags Or CC_ENABLEHOOK
.lpfnHook = FARPROC(AddressOf ChooseColorProc)
'size of structure
.lStructSize = Len(CC)
'assign the custom colour selections
.lpCustColors = VarPtr(dwCustClrs(0))
End With

RBS

"RB Smissaert" <bartsmissa...@xxxxxxxxxxxxxxxx> wrote in message

news:%23vsAMKwGIHA.5544@xxxxxxxxxxxxxxxxxxxxxxx



Try this:

Instead of calling AddressOf directly call it via a function like this:

Function FARPROC(ByVal pfn As Long) As Long

FARPROC = pfn

End Function

RBS

<crfergu...@xxxxxxxxx> wrote in message
news:1193753665.771584.224290@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
OK, so I'm pretty new to API's so forgive me if this is an idiot
question :-)

I'm putting together a class that uses API calls to user32 to
enumerate and list all running applications by their Title text. One
of the functions uses "AddressOf AnotherFunctionName" to accomplish
this. The code works fantastic in a module. However, when trying to
migrate this to a reusable class, the code crashes on that line with
an error of:

"Invalid use of AddressOf operator"

Looking in Help it says:
"You tried to use AddressOf with the name of a class method.
Only the names of Visual Basic procedures in a .bas module can be
modified with AddressOf. You can't specify a class method."

Well, shucks, that just popped my bubble of wanting to make this code
really efficient by keeping it in a class amongst some other utility
functions I've written. Seems I can only use it in a module instead.

My question is this: Is there a way to work around this in a class?
Here's my working module code that simply returns a Long greater than
zero if an app with all or part of the passed title is found to be
running:

==================================
Option Explicit

Private Declare Function EnumWindows Lib "user32" (ByVal lEnumFunc As
Long, ByVal wParam 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 Type AppWindow
sTitle As String
lHandle As Long
End Type

Public Function FindWindowByTitle(ByVal TheWindowTitle As String) As
Long
'We'll pass a custom structure in as the parameter to store our
result...
Dim tParms As AppWindow
tParms.sTitle = TheWindowTitle

Call EnumWindows(AddressOf GetWindowTitles, VarPtr(tParms))

FindWindowByTitle = tParms.lHandle
End Function

Private Function GetWindowTitles(ByVal TheHandle As Long, TheParms As
AppWindow) As Long
Dim sTitleText As String

'set a generic 260 length empty string to catch the window text
sTitleText = Space(260)
'get the text
Call GetWindowText(TheHandle, sTitleText, 260)
'remove nulls from the text
sTitleText = TrimNull(sTitleText)

'check to see if all or part of the search string is found
'in the window text
If sTitleText Like TheParms.sTitle Then
'if a match is found, then set the handle number
TheParms.lHandle = TheHandle
'and then exit the function
GetWindowTitles = 0
End If

'reset to 1 to keep the recursive loop going if not match found
GetWindowTitles = 1
End Function

Private Function TrimNull(ByVal TheText As String)
'check to see if string has null characters on the end
If Not InStr(TheText, Chr$(0)) = 0 Then
'if so, then remove the null characters from the end
TheText = Left$(TheText, InStr(TheText, Chr$(0)) - 1)
End If
TrimNull = TheText
End Function
=======================================

Of course the usage of this would be to pass a string to the only
public function FindWindowByTitle.

Thanks for any light that can be shed on this.

Cory- Hide quoted text -

- Show quoted text -


.

Relevant Pages

  • Re: API Class Question
    ... .flags = .flags Or CC_FULLOPEN ... >> (ByVal hWnd As Long, ByVal lpString As String, ByVal cch As Long) As ... >> Call EnumWindows(AddressOf GetWindowTitles, VarPtr(tParms)) ... >> Dim sTitleText As String ...
    (microsoft.public.excel.programming)
  • Re: API Class Question
    ... .flags = .flags Or CC_FULLOPEN ... Private Declare Function EnumWindows Lib "user32" (ByVal lEnumFunc As ... (ByVal hWnd As Long, ByVal lpString As String, ByVal cch As Long) ... Dim sTitleText As String ...
    (microsoft.public.excel.programming)
  • Re: API Class Question
    ... .flags = .flags Or CC_FULLOPEN ... "You tried to use AddressOf with the name of a class method. ... (ByVal hWnd As Long, ByVal lpString As String, ByVal cch As Long) ... Dim sTitleText As String ...
    (microsoft.public.excel.programming)
  • Re: API Class Question
    ... .flags = .flags Or CC_FULLOPEN ... "You tried to use AddressOf with the name of a class method. ... (ByVal hWnd As Long, ByVal lpString As String, ByVal cch As Long) ... Dim sTitleText As String ...
    (microsoft.public.excel.programming)
  • Re: API Class Question
    ... procedure in a class module with AddressOf. ... Private Declare Function EnumWindows Lib "user32" (ByVal lEnumFunc As ... (ByVal hWnd As Long, ByVal lpString As String, ByVal cch As Long) ... Dim sTitleText As String ...
    (microsoft.public.excel.programming)