Ask for Help (v2) • Re: Get the return value from TC by SendMessage

CODE:

AcSide:=TC_GetActiveSide()
MsgBox AcSide

TC_GetActiveSide()
{
    ;https://wincmd.ru/forum/viewtopic.php?p=110848&sid=0dfde01723b39e508e96d62c00a7a9b5
    If WinExist("ahk_class TTOTAL_CMD") ;&& WinActive("ahk_class TTOTAL_CMD")
    {
        OnMessage(0x4a, TC_Receive_WM_COPYDATA)  ; 0x4a is WM_COPYDATA
        TC_Send_WM_COPYDATA(cmd:="A")
        return retVal
    }
    else
        return "TC does NOT exist"
}

TC_Send_WM_COPYDATA(cmd){
    
    Critical
    if(!RegExMatch(cmd, "^(A|[LRST][PCIN]?)$"))
        return
    static dwData:=Ord("G") + 256 * Ord("W")
    static WM_COPYDATA := 0x4A
    cbData := Buffer(StrPut(cmd, 'CP0'))
    StrPut(cmd, cbData, 'CP0')
    CopyDataStruct:=Buffer(A_PtrSize * 3)
    NumPut('Ptr', dwData, 'Ptr', cbData.size, 'Ptr', cbData.ptr, COPYDATASTRUCT)
    MsgResult:=SendMessage(WM_COPYDATA, A_ScriptHwnd, CopyDataStruct, , "ahk_class TTOTAL_CMD")
    return MsgResult
}

TC_Receive_WM_COPYDATA(wParam, lParam, msg, hwnd)
{
  global retVal
  PtrPos:=NumGet(lParam + A_PtrSize * 2,0,"Ptr")
  retVal:=StrGet(PtrPos)
  return 1
}