C / C++ / MFC

24-Sep-09 5:49

Hi a quick question
if I allocate a cdialog derived object via
the new operator
just so I can save data in the object
that won't associate with windows resource
until I do the create specfing the dialog item
from the resource file
after the create. The framework should call
my ::initdialog overideable

sounds right ??

Btw in the create is where I would specify
the dialog item resource

David Crow24-Sep-09 7:09

24-Sep-09 7:09

ForNow wrote:
if I allocate a cdialog derived object via
the new operator
just so I can save data in the object

Just for the sake of saving data, why would you want to do this?

ForNow wrote:
that won't associate with windows resource
until I do the create specfing the dialog item
from the resource file
after the create. The framework should call
my ::initdialog overideable

Wouldn't it be easier to just code it up and see (when OnInitDialog() is called)?

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ForNow24-Sep-09 7:29

24-Sep-09 7:29

I have two threads providing information
for the dialog
which ever finishes first I'll save that info
in a Cstring member of the CDialog derived
object
When the second thread finishes and I'am
ready to display the Cdialog I'll do the
Create to get things going

Thank

David Crow24-Sep-09 8:01

24-Sep-09 8:01

Ok, but why use a heap-based CDialog object?

ForNow24-Sep-09 8:08

24-Sep-09 8:08

Since I need this storage while the Cdialog
exists it seems like a good place to save the
Data

David Crow24-Sep-09 8:10

24-Sep-09 8:10

Saving the data in the dialog object is fine. I'm just curious why you think it needs to be heap-based. Are you creating it in one place and then doing the thread-related code elsewhere?

ForNow24-Sep-09 8:24

24-Sep-09 8:24

I just if I Created it on the I guess stack
e.g. Cdialog mydialog then
1) I would have to pass the Cdialog constructed
paramters such as the dialog resource item
to initialize the windows object
2) the CDialog objects would be lost between
the windows/framwork messages

waiting for the second thread to complete
with the rest of the data

thankx

David Crow24-Sep-09 8:32

24-Sep-09 8:32

ForNow wrote:
1) I would have to pass the Cdialog constructed
paramters such as the dialog resource item
to initialize the windows object
2) the CDialog objects would be lost between
the windows/framwork messages

What does this mean?

Consider these two statements:

CMyDialog dlg;
dlg.DoModal();

The dialog window itself and any controls on it do not exist until DoModal() is called, so you can access non-UI member variables of the dialog object until the object goes out of scope.

I'm not saying you have to do it this way, I was just questioning why you thought you had to do it the other way. Either way works, one just unnecessarily involves the memory manager.

ForNow24-Sep-09 8:50

24-Sep-09 8:50

I am using a modeless dialog box
so Create I guess attaches the MFC
object to to the Windows Dialog

I also need the storage of the CDialog
saved between Windows messages

If I save the address of dlg in a CDialog *
would be around (the storage area of dlg)
between Windows messages????

Thankx again

DWORD Time Puzzle

phil241524-Sep-09 5:36

24-Sep-09 5:36

I know this isn't strictly a C++ problem but the application in question is written in C++ and this seems to be as good a place as any for some genius to come across this and answer it!

OK, I have this puzzle that's been driving me crazy for over a week. Perhaps if I explain it to you someone can help me to crack it!

I'm trying to replicated the behaviour of some software. It's a digital signage system and consists of a server application running, at the moment, on my PC, and a client which is a giant LCD screen with a built-in PC running Windows XP Embedded. In case anyone's familiar with it the sofware is MagicInfo by Samsung.

The server application has the option to create an alert ticker message. It can be formatted, colours selected, etc. And when it's ready you hit the 'Send' button in the server console and instantly the message appears on the remote client screen. It'll keep running for the length of time I specified in the message setup or I can stop it by pressing the 'Stop' button in the server console.

I've determined that the message itself and its formatting is contained in a simple XML file, which I'll paste below. Every time I update the message in the server the XML file on the client is updated. So, it's simple for me to come up with my own way to change the message.

The hard part is how to trigger the display of the message. Remember, it can't be scheduled, it only appears when that 'Send' button is pressed. I have searched high and low on the client for SOMEWHERE that might store the on/off flag, or SOME indication of what changes when the message is activated.

Getting in a bit over my head I've used network sniffer programs to examine the data packets sent between the server and the client when the message is activated and, sure enough, I can see the text of the updated message being sent. The client is permanently running a little application called XL_TICKER which seems to just sit there and wait for these packets from the server. However, attempting to replicate the packets manually with my limited knowledge has thus far failed to trigger the message on the client.

So here's the puzzle. The ONLY thing that appears to change on the client each time I trigger the message (other than the XML file itself) is an entry in the Windows Registry, in a node containing various details about MagicInfo. There are two keys, called TickerStartTimeHigh and TickerStartTimeLow. These are DWORD values. The latter, TickerStartTimeLow, changes every time I trigger the ticker message. The other one only changes sometimes. I'm desperately hoping that somehow the client checks these values continually and, depending on what the values are, displays the message. I know it's a long shot but since I can find nothing else on the client that changes with the triggering of the ticker message I've got nothing else to go on.

The problem is that the values in these keys make no sense at all. I don't even know why there would be a HIGH and a LOW start time. Here are some examples of the values in the keys. If anybody can work out how these relate to time or, indeed, what they mean, I'd be eternally grateful!

Link to table of DWORD values at various times

I know it looks as if the TickerStartTimeHigh might simply be an incremental value, going up one each time, but sometimes it doesn't change from one triggering of the message to the next. It does, however, seem to go up by very small amounts over time, whereas TickerStartTimeLow leaps up by thousands, then all of a sudden drops by thousands, as if it's reaches a maximum and started again (although only rises are seen in the data above). I can only assume that the actual time or significant value is a derivation of the two numbers, but again - why store it in this way?

FWIW, here's the text of the XML file for the ticker:

<?xml version="1.0" encoding="utf-8"?>
<root>
<Ticker>
<Text>The text of the message goes here</Text>

</Ticker>
<Time>00:02:00</Time>
<BottomPosition>True</BottomPosition>
<Direction>Right To Left</Direction>
<Speed>95</Speed>
<Step>1</Step>
<Font>Arial</Font>
<Size>70</Size>
<Italic>False</Italic>
<Bold>True</Bold>
<UnderLine>False</UnderLine>
<Strikeout>False</Strikeout>
<HLocation>Center</HLocation>
<TextColor>16777215</TextColor>
<BackgroundColor>255</BackgroundColor>
<Transparency>100</Transparency>
</root>

Stuart Dootson24-Sep-09 6:13

Stuart Dootson

24-Sep-09 6:13

The time is a FILETIME[^]. In fact, here's a little program that confirms that by using one of the times you give in your link, assigning it to a FILETIME and converting that to a SYSTEMTIME and writing out the time parts.

#include <Windows.h>
#include <iostream>

int main()
{
  SYSTEMTIME st;
  FILETIME ft;
  ft.dwLowDateTime = 2960830672;
  ft.dwHighDateTime = 30031143;
  FileTimeToSystemTime(&ft, &st);
  
  std::cout << st.wYear << std::endl;
  std::cout << st.wMonth << std::endl;
  std::cout << st.wDay << std::endl;
  std::cout << st.wHour << std::endl;
  std::cout << st.wMinute << std::endl;
  std::cout << st.wSecond << std::endl;
}

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

phil241525-Sep-09 3:46

25-Sep-09 3:46

Thanks Stuart, I'm so grateful that you were able to crack that one! Your code looks tantalisingly simple, but unfortunately I don't know C(++) at all and don't have anything to compile it with. I know VB.NET, though, and in fact that's what I'm using to write the program I'm hoping to incorporate this into. I've spent most of today Googling FileTime and SystemTime, creating my own structures in VB.NET and trying to achieve the feat of extracting the parts of the date as you have, but so far without success. At the moment it's returning a year of "67137" and a month of "65537", which seem completely meaningless to me and suggest that I've totally misunderstood what I'm doing and have just got lucky and managed to compile some code which will actually run, however pointless!

I don't suppose you know how to achieve what your code does in VB.NET, do you?

Stuart Dootson25-Sep-09 4:12

Stuart Dootson

25-Sep-09 4:12

I'd start with Pinvoke.net[^], as that contains code snippets for declaring the necessary structures and function declarations.

Once you've got those definitions in your code, the VB.NET code should follow logically form the C++ code - all I do is set the FILETIME structure to your time parts, call FileTimeToSystemTime and extract the date/time parts.

This page[^] might also help.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

phil241525-Sep-09 5:03

25-Sep-09 5:03

I've already been on Pinvoke.net and it seems that I have my structures and functions declared correctly. At the moment, using the same figures you plugged into your C code, I'm getting a year of "67137", a month of "65537" and a day of "5439544", without going into the hours, etc. Am I completely on the wrong track or are these numbers correct and just in need of some kind of further conversion to a date I an actually understand?

Stuart Dootson25-Sep-09 10:48

Stuart Dootson

25-Sep-09 10:48

Imports System
Imports System.Runtime.InteropServices

Module Module1

    <StructLayout(LayoutKind.Sequential)> _
    Public Structure FILETIME
        Public dwLowDateTime As UInteger
        Public dwHighDateTime As UInteger

        Public ReadOnly Property Value() As ULong
            Get
                Return CType(dwHighDateTime << 32, ULong) + dwLowDateTime
            End Get
        End Property
    End Structure

    <StructLayout(LayoutKind.Sequential)> _
    Public Structure SYSTEMTIME
        <MarshalAs(UnmanagedType.U2)> Public Year As Short
        <MarshalAs(UnmanagedType.U2)> Public Month As Short
        <MarshalAs(UnmanagedType.U2)> Public DayOfWeek As Short
        <MarshalAs(UnmanagedType.U2)> Public Day As Short
        <MarshalAs(UnmanagedType.U2)> Public Hour As Short
        <MarshalAs(UnmanagedType.U2)> Public Minute As Short
        <MarshalAs(UnmanagedType.U2)> Public Second As Short
        <MarshalAs(UnmanagedType.U2)> Public Milliseconds As Short
    End Structure

    <DllImport( _
               "kernel32.dll", _
               CharSet:=CharSet.Auto, _
               SetLastError:=True)> _
           Public Function FileTimeToSystemTime( _
                                <[In]()> ByRef lpFileTime As FILETIME, _
                                <Out()> ByRef lpSystemTime As SYSTEMTIME) _
                       As Boolean
    End Function

    Sub Main()
        Dim st As SYSTEMTIME
        Dim ft As FILETIME

        ft.dwLowDateTime = 2960830672
        ft.dwHighDateTime = 30031143
        FileTimeToSystemTime(ft, st)

        System.Console.WriteLine(st.Year)
        System.Console.WriteLine(st.Month)
        System.Console.WriteLine(st.Day)
        System.Console.WriteLine(st.Hour)
        System.Console.WriteLine(st.Minute)
        System.Console.WriteLine(st.Second)
    End Sub

End Module

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

phil241527-Sep-09 23:05