WM_COPYDATA return

[MrCreatoR]

I am trying to return from WM_COPYDATA call.

If i use it for my own process, sometimes i get correct results, strange but it's randomly returns the correct result.

If i send from external process, my script crashes, what i am doing wrong? 

 

#include <WindowsConstants.au3>

$hGUI = GUICreate('')
GUIRegisterMsg($WM_COPYDATA, '_WM_COPYDATA')

Do
    $sRet = _Send($hGUI)
Until $sRet

MsgBox(64, @ScriptName, $sRet)

Func _Send($hWnd)
    $aRet = DllCall('user32.dll', 'ptr', 'SendMessage', 'hwnd', $hWnd, 'uint', $WM_COPYDATA, 'ptr', 0, 'ptr', 0)
    
    $stData = DllStructCreate('dword iLen;ptr pStr', Ptr($aRet[0]))
    $iLen = DllStructGetData($stData, 'iLen')
    $pStr = DllStructGetData($stData, 'pStr')
    $stStr = DllStructCreate('wchar sStr[' & $iLen & ']', Ptr($pStr))
    
    Return DllStructGetData($stStr, 'sStr')
EndFunc

Func _WM_COPYDATA($hWnd, $iMsg, $wParam, $lParam)
    $vRet = 'Test'
    
    $iLen = (StringLen($vRet) * 2) + 3
    $stData = DllStructCreate('dword iLen;ptr pStr')
    $stStr = DllStructCreate('wchar sStr[' & $iLen & ']')
    
    DllStructSetData($stStr, 'sStr', $vRet)
    DllStructSetData($stData, 'iLen', $iLen)
    DllStructSetData($stData, 'pStr', DllStructGetPtr($stStr))
    
    Return DllStructGetPtr($stData)
EndFunc

 

[Iczer]

To receive wm_copydata message i'm use something like this:

Func __WM_COPYDATA($hWnd, $MsgID, $wParam, $lParam)
    
    Local $tCOPYDATA = DllStructCreate("ulong_ptr;dword;ptr", $lParam), $tData, $iID

    ;ConsoleWrite("__WM_COPYDATA :: "&$MsgID & " --> " & DllStructGetData($tCOPYDATA, 1) & "/" & DllStructGetData($tCOPYDATA, 2) & "/" & DllStructGetData($tCOPYDATA, 3) & @CRLF)

    Switch DllStructGetData($tCOPYDATA, 1)

        Case $IPCMessage_Num1
            ;----------------------------------------------------------------------------------
            $tData = DllStructCreate($tagData, DllStructGetData($tCOPYDATA, 3))
            $iID = DllStructGetData($tData, 2)
            $iSizeOfTVStateStructure= DllStructGetData($tData, 1)
            ;----------------------------------------------------------------------------------
            ;ConsoleWrite("$IPCMessage_Num1 :: "&$iID & " --> " & DllStructGetData($tData, 2) & "/" & DllStructGetData($tData, 3) & "/" & DllStructGetData($tData, 4) & @CRLF)

            $aGlobal[$iID][4]  = DllStructGetData($tData, 3)
            $aGlobal[$iID][5]  = DllStructGetData($tData, 4)
            $aGlobal[$iID][15] = DllStructGetData($tData, 6)
            $aGlobal[$iID][23] = DllStructGetData($tData, 5)
            $aGlobal[$iID][25] = DllStructGetData($tData, 6)
            $aGlobal[$iID][26] = DllStructGetData($tData, 7)
            $aGlobal[$iID][27] = DllStructGetData($tData, 8)
            $aGlobal[$iID][31] = DllStructGetData($tData, 9)
            ;----------------------------------------------------------------------------------
            ;
            ;----------------------------------------------------------------------------------
        Case $IPCMessage_Num2
            ...
            
            
    EndSwitch
    ; -------------------------------------------------------------------------------------
    Return 0
EndFunc   ;==>WM_COPYDATA

its working without crashes...

[Nine]

That works fine for me :

expandcollapse popup

#include <GUIConstants.au3>
#include <SendMessage.au3>

$hGUI1 = GUICreate('Test1')
$hGUI2 = GUICreate("Test2")

ConsoleWrite ($hGUI1 & "/" & $hGUI2 & @CRLF)

GUIRegisterMsg($WM_COPYDATA, _WM_COPYDATA)

Sleep (500)

$sRet = _Send($hGUI1, $hGUI2, "Test")
ConsoleWrite ($sRet & @CRLF)

Sleep (500)

$sRet = _Send($hGUI2, $hGUI1, "OK")
ConsoleWrite ($sRet & @CRLF)

Sleep (1000)

Func _Send($hWndFrom, $hWndTo, $sString)
  Local $stData = DllStructCreate('ULONG_PTR data;dword iLen;ptr')
  $stData.iLen = 20
  Local $stStr = DllStructCreate('char sStr[' & $stData.iLen & ']')
  $stStr.sStr = $sString
  $stData.data = DllStructGetPtr($stStr)
  Return _SendMessage ($hWndTo, $WM_COPYDATA, $hWndFrom, DllStructGetPtr($stData))
EndFunc

Func _WM_COPYDATA($hWnd, $iMsg, $wParam, $lParam)
  Local $stData = DllStructCreate('ULONG_PTR data;dword iLen;ptr', $lParam)
  Local $iLen = $stData.iLen
  Local $stStr = DllStructCreate('char sStr[' & $iLen & ']',$stData.data)
  ConsoleWrite ("Received = " & $iLen & "/" & $hWnd & "/" & $wParam & "/" & $stStr.sStr & @CRLF)
  Return 1
EndFunc

Func _Exit ()
  Exit
EndFunc

I have put the 2 windows into the same script for simplicity.

[MrCreatoR]

Yes but where is the return?

I know how to get the data sent to WM_COPYDATA, but i need to pass back some data to the process that has sent the data.

Not just number (btw we can send as binary only 4 chars), but text, arrays...

Edited April 28, 2020 by MrCreatoR

[Nine]

just put the string in a global variables, and make the a boolean to indicate reception in the winproc function

[Iczer]

you can send pointer to any data:

Function IPCMessageSend_ToMainGUI(ByRef IPCMessage As IPCMessageConst, ByRef iID As ULong = 0, ByRef AnyData As Any Ptr = 0) As Long
    
    Dim As tagCOPYDATASTRUCT Ptr ptDataToSend = New COPYDATASTRUCT
    
    Select Case As Const IPCMessage
        ' ...........................................................
        Case IPCMessage_DataSingle
        ' ...........................................................
            Dim As tagData Ptr ptData = New tagData[1]
            
            ptData[0]   = iID
            
            ptDataToSend->dwData = IPCMessage
            ptDataToSend->cbData = SizeOf(*ptData)
            ptDataToSend->lpData = ptData
            
            SendMessage(hWndMainGUI, WM_COPYDATA, 0, Cast(lparam, ptDataToSend))
            
            Delete[] ptData
            
            
    End Select
    ' ..............................................................
    Delete ptDataToSend
    ' ..............................................................
    Return 1
End Function

 

[MrCreatoR]

24 minutes ago, Iczer said:

you can send pointer to any data:

Can you show it please on AutoIt script example?

[MrCreatoR]

I thought that i can do it using ReadProcessMemory, but i don't have a clue how to do this. I can pass the PID in the return, but not together with memory address.

[Iczer]

Function IPCMessageSend_ToMainGUI(ByRef $IPCMessage, ByRef $stringData) As Long
    
    Local $tDataToSend = DllStructCreate("ulong_ptr dwData;dword cbData;ptr lpData", $lParam)
    
    Switch $IPCMessage
        ' ...........................................................
        Case IPCMessage_DataSingle
        ' ...........................................................
            Local $tData = DllStructCreate('char sStr[' & StringLen($stringData)+1 & ']')
            
            $tData.sStr = $stringData
            
            tDataToSend.dwData = $IPCMessage
            tDataToSend.cbData = StringLen($stringData)+1
            tDataToSend.lpData = DllStructGetPtr($tData)
            
            _SendMessage ($hWndMainGUI, $WM_COPYDATA, 0, DllStructGetPtr($tDataToSend))
    End Switch
    ' ..............................................................
    Return 1
End Function

 

[MrCreatoR]

Thanks, but...

It's sending the data to WM_COPYDATA, i need to get the return from it (by _SendMessage).

[Nine]

1 hour ago, MrCreatoR said:

It's sending the data to WM_COPYDATA, i need to get the return from it (by _SendMessage).

But Why ?  What do you expect/want to receive from the SendMessage function?  You already know all informations that is sent to the other window.

[MrCreatoR]

Just now, Nine said:

But Why ?

To send back some data.

1 minute ago, Nine said:

What do you expect/want to receive from the SendMessage function?

I want to receive any kind of data, first post shows what i am trying to do.

[Nine]

My post shows you how to exchange data between 2 windows (and it is working perfectly fine as you can test it yourself).  I think you do not understand how it is working...because your code in OP doesn't make much sense, imho.

[MrCreatoR]

7 minutes ago, Nine said:

My post shows you how to exchange data between 2 windows

Exchange one way, i need two ways.

Your script will return only 1 (int), i need strings, arrays.

 

7 minutes ago, Nine said:

your code in OP doesn't make much sense, imho

It's simple, when we send data to WM_COPYDATA, it receives it, but not returning anything back.

Maybe this example will show better what i need:

#include <WindowsConstants.au3>
#include <WinAPIMem.au3>

$hGUI = GUICreate('')
GUIRegisterMsg($WM_COPYDATA, '_WM_COPYDATA')

$sRet = _Send($hGUI)
MsgBox(64, @ScriptName, $sRet)

Func _Send($hWnd)
    $aRet = DllCall('user32.dll', 'ptr', 'SendMessage', 'hwnd', $hWnd, 'uint', $WM_COPYDATA, 'ptr', 0, 'ptr', 0)
    Return _WinAPI_GetString($aRet[0])
EndFunc

Func _WM_COPYDATA($hWnd, $iMsg, $wParam, $lParam)
    Return _WinAPI_CreateString('Test')
EndFunc

It works for the same process, but if i send from other script, it wont work.

Edited April 28, 2020 by MrCreatoR

[Nine]

My code shows both ways first it is from 1 to 2 (test) and then 2 to 1 (ok).

[MrCreatoR]

9 minutes ago, Nine said:

I think you do not understand how it is working

I do.

[MrCreatoR]

1 minute ago, Nine said:

My code shows both ways first it is from 1 to 2 (test) and then 2 to 1 (ok).

But the return from SenMessage is only '1' (int), not string (for example).

[Nine]

Who cares what it returns, you know what you have sent to the other windows.  What do you want more ?

[MrCreatoR]

I want to return pointer instead of just '1' and pull out the data from it using structures, but thats not working from external process, probably i need to use ReadProcessMemory somehow...

[Nine]

A pointer to what structure ?  But whatever, have fun with your readprocessMemory.  I am out.