C / C++ / MFC Discussion Boards

Re: Membership in Thread is defined by object or by method ?

Mike Dimmick12-Sep-03 5:26

12-Sep-03 5:26

Unless you're going through COM, there is no synchronisation between threads. If going through COM (i.e. one object is created using CoCreateInstance), a proxy may be added by COM if the threading models don't match.

You should perform your own synchronisation wherever needed.

How to use the Word Object Library in VC++?

GTS202012-Sep-03 2:52

GTS2020

12-Sep-03 2:52

Hi All,

I am new to the VC++ development.
I am using the Word Object Library in Visual Basic,
Now I wanted to do the same in VC++.
I want to use it in console mode.

May you give me guidance to do the same.

Thanks.

GTS

Re: How to use the Word Object Library in VC++?

David Crow12-Sep-03 2:56

David Crow

12-Sep-03 2:56

Check out MSDN article Q178749.

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Re: How to use the Word Object Library in VC++?

GTS202012-Sep-03 3:21

GTS2020

12-Sep-03 3:21

Hi David,

You showed the perfect start place.

Thanks.

GTS

PS - 5 birds left, 3 of them only decided not fly away yet.

Chat - Program

pillepop12-Sep-03 2:37

pillepop

12-Sep-03 2:37

Hey all,

Im new to C++ and MFC and am trying to write a chat program for direct IP connections via TCP/IP.
For that I derived a class from CAsyncSocket, createt an Instance (m_ConnectSocket) and can now send CStrings via
m_ConnectSocket.Send(Data, Len) and receive them with
m_ConnectSocket.Receive(Buffer, BufferSize)

1.How can I now send and receive different variables...and distinguish them?
I just dont know how to use some kind of flag.

2.Also I would like to know how to get the Length of other objects...e.g. if i want to send a whole struct or Instance of another class.

Please help me

Re: Chat - Program

Roger Stoltz12-Sep-03 3:59

Roger Stoltz

12-Sep-03 3:59

Something tells me that this is not just a "chat" program since you want to "send and receive variables".
What kind of a problem are you trying to build a solution for?
(Looks like asking: "I've bought a boat. How can I make it fly?" instead of asking "I want to go to the moon. How can I get there?" Wink | ;)

)

pillepop wrote:
1.How can I now send and receive different variables...and distinguish them?
I just dont know how to use some kind of flag.

2.Also I would like to know how to get the Length of other objects...e.g. if i want to send a whole struct or Instance of another class.

This looks like you want to transfer binary data (all kinds of variables) over a TCP/IP connection. Take a look at MSDN samples CHATSRVR and CHATTER. The messages sent could easily be altered to send binary data instead. The CMsg object sent over the TCP/IP connection contains a few variables. If you send similar objects looking like this:

class CMsg : public CObject
{
protected:
DECLARE_DYNCREATE(CMsg)

public:
CMsg();
virtual ~CMsg();
virtual void Serialize(CArchive& ar);

DWORD m_dwCommand; //Tells the receiver how to interpret the data
DWORD m_dwLength;  //The length of the binary data section
BYTE* m_pBinaryData; //Command specific data (variable values)
BOOL m_bClose;
};

you could send just about anything across the connection, including structures as long as the receiver knows how to interpret the data by reading the m_dwCommand value.

If this is not what you are after: forget the whole thing above! Laugh | :laugh:

If this is your problem I hope this helped or maybe you should have a look at DCOM where you create a component on a different machine and communicate with it through an interface via RPC (TCP/IP).
But that's a different ball game!
If you are interested in DCOM there are very useful articles here at CodeProject.

--
Rog

Re: Chat - Program

pillepop12-Sep-03 5:39

pillepop

12-Sep-03 5:39

thanks for the answer

Hehe, good point.

Actually I started off building a chat-prog... and am now trying to enhance it a bit Wink | ;)

First thing I meant was: I have 2 edit boxes whose contents are sent 2 the receiver, who then in turn has to show them again in different edit-boxes.
... doesnt this work with the normal send() and receive() function?

Well, and furthermore i want to transmit several integer ... as struct or whatever. That a bit more specific? Smile | :)

It might be a stupid question, but do I need .net for the MSDN samples? Unfortunately I cant open the .sln (got vc++)

Re: Chat - Program

Peter Weyzen12-Sep-03 10:26

Peter Weyzen

12-Sep-03 10:26

Here's a good hint from writing software. Always do your best to seperate your UI from your back-end.

Your issues of how to display stuff is one thing, but what you actually intend to do here is: post a interpretable message from one client to another. Most chat programs do this by either using a specific packet/message format -- or use some "RPC".

Ignore the RPC for now.

What I think you need to do, is define a message format. This message format is something used by one client to convey one of many possible messages to another client.

The message that you want to send needs to be able to contain:
* identification of what type of message you are sending
* its good to include the size of the whole message
* and the "message" itself.

I should say, that my use of the word "message" should not be confused with a "chat message". This is a broader term for any bit of communication from one client to another.

In instant messaging, these messages are commonly:
* "instant message"
* "i want to log in and here's my password"
* "i am logging off"
* "here's a file"
* "i am away"

stuff like that.

You might consider XML as a nice and easily interpretable way to send messages.

But more often than not, the "message" is sent a data block.

Here's a possible message format -- this is a "message header";
[Message-Type: stored as a DWORD]
[Message-Length: stored as a DWORD]

With this information, you can now interpret the packet/message to determine what the caller wants to tell you. Message-Type of (3) might mean that you are "away". and a (6) might mean "i want to transfer a file".

Depending on the message ID, the data that follows will be in the format appropriate to that message type....

I'll leave you with this -- but I hope these clues help.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br />
Peter Weyzen<br />
Staff Engineer<br />
<A HREF="http://www.santacruznetworks.com">Santa Cruz Networks</A>

Menu in MFC

cberam12-Sep-03 1:53

cberam

12-Sep-03 1:53

Hi,

can anyone help how to create a Menu dynamically in a MFC application ?
Thanks in advance

ram

Re: Menu in MFC

vcplusplus12-Sep-03 2:42

vcplusplus

12-Sep-03 2:42

http://www.codeproject.com/menu/dynitems.asp

Re: Menu in MFC

Mike O'Neill12-Sep-03 15:59

Mike O'Neill

12-Sep-03 15:59

The AppWizard-generated class for your main window is named CMainFrame and it's derived from CFrameWnd. CFrameWnd, in turn, is derived from CWnd, and CWnd has a bunch of easy-to-use member functions like SetMenu(). Play around with those.

Check if file is executable

peterchen12-Sep-03 1:43

peterchen

12-Sep-03 1:43

Hi,
is there a Win32 API to check if a file is an executable (that can be passed to CreateProcess)?

IIRC there was one, but I can't remember....

"Dor säggsische Dialeggt eechnet sich wie keeen onderor für den Ausdrugg zäärdlischor Gefiehle."

sighist | Agile Programming | doxygen

Re: Check if file is executable

geo_m12-Sep-03 2:38

geo_m

12-Sep-03 2:38

I don't know any direct API that can be just called with filename returning true/false if it's a EXE.

This one can be a good starter - doing something different, but in fact very similar Wink | ;-)

Q90493 - HOWTO: How To Determine Whether an Application is Console or GUI

Or I would look to Image Help Library (obsolete - better use DbgHelp) might be there will be some handy functions.

hope this helps

Re: Check if file is executable

vcplusplus12-Sep-03 2:48

vcplusplus

12-Sep-03 2:48

Try using SHGetFileInfo(,SHGFI_EXETYPE,,,);

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/shell/reference/functions/shgetfileinfo.asp

Re: Check if file is executable

David Crow12-Sep-03 7:31

David Crow

12-Sep-03 7:31

Which would not work on files such as screen savers.

SHGetFileInfo(_T("C:\\WINNT\\system32\\ssbezier.scr"), 0, &fi, sizeof(fi), SHGFI_EXETYPE);

Would return a value of 0, indicating it is not an executable, when in fact it is.

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Re: Check if file is executable

David Crow12-Sep-03 7:33

David Crow

12-Sep-03 7:33

Try this code snippet:

HANDLE              hFile;
IMAGE_DOS_HEADER    DosHeader;
DWORD               dwBytes,
                    dwBytesRead;
IMAGE_NT_HEADERS    NTHeader;
 
hFile = CreateFile(szFilename, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
if (INVALID_HANDLE_VALUE  != hFile)
{
    dwBytes = sizeof(IMAGE_DOS_HEADER);
    if (ReadFile(hFile, &DosHeader, dwBytes, &dwBytesRead, NULL) != FALSE)
    {
        SetFilePointer(hFile, DosHeader.e_lfanew, NULL, FILE_BEGIN);
 
        dwBytes = sizeof(IMAGE_NT_HEADERS);
        ReadFile(hFile, &NTHeader, dwBytes, &dwBytesRead, NULL);
 
        if ((NTHeader.FileHeader.Characteristics & IMAGE_FILE_EXECUTABLE_IMAGE) == IMAGE_FILE_EXECUTABLE_IMAGE)
            MessageBox(_T("File is executable"), _T(""), MB_OK);
    }
 
    CloseHandle(hFile);
}

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Threads and object

El'Cachubrey12-Sep-03 1:07

El'Cachubrey

12-Sep-03 1:07

Hi all

My application used 2 threads ,2 apartments more exactly. First one is main STA and second is MTA. Into main STA I create COM object , approximately this way:

Void main(){
CoInitializeEx(NULL,COINIT_MULTITHREADED);
CmyObjPtr pObj(CLSID_ CmyObjPtr);
pObj->DoSomethere();
…
}

Sometime arise distinguished trouble my object invoke itself method (ie pObj->DoSomethere();) haven’t time to be created because of it accomplished into other thread.

How I can avoid this??? I try to use a great deal of synchronized methods, for this purpose such as creating critical section in DllGetClassObject function and this code

While(pObj == NULL){
Sleep(10);
}

But program not exit from this loop if pObj don’t be created from enter into loop.

Thanks.

Re: Threads and object

Dangleberry12-Sep-03 1:36

Dangleberry

12-Sep-03 1:36

You need to use a CRITICAL_SECTION or MUTEX to force the thread not to continue until the other thread holding the MUTEX returns it. Basically wrap the initialisation up in the mutex so you know it will complete it before the component is used. MSDN will be able to help you on this, its a bit too involved to explain on the forum.

Alan.

Where can I find a table of all functions inside in kernel32.dll?

Tommy Svensson12-Sep-03 0:34

Tommy Svensson

12-Sep-03 0:34

Hi all,

I'm trying to add a splash screen to a dll inside DllMain (process_attach) and the docs says there are lots to think about. E.g I can not call functions outside kernel32.dll, etc...

Now I need to know where I can find a table of all functions listed in kernel32.dll? Anyone?

The docs also says I can not call any registry functions... by if I want to do this, how can I go on?!

/Tommy

Re: Where can I find a table of all functions inside in kernel32.dll?

El'Cachubrey12-Sep-03 0:53

El'Cachubrey

12-Sep-03 0:53

if you mean name of this function then you can use Depends application from VC tools.

Re: Where can I find a table of all functions inside in kernel32.dll?

Mike Dimmick12-Sep-03 2:15

Mike Dimmick

12-Sep-03 2:15

The reason for the restriction is that you don't know what order the loader will decide to initialise DLLs in, and you shouldn't use any DLL that hasn't been initialised.

The only DLL it's always safe to use at this point is kernel32.dll, because that's where the Win32 bit of process setup lives - it's guaranteed to be initialised first.

A large amount of the GUI code lives in User32.dll and Gdi32.dll, so you shouldn't do what you're proposing to do. If you must do it, delay it until some other function in your DLL is called. Personally I would advise not doing it at all.

For information on how the .NET Framework breaks these rules, and the impact that has, read Chris Brumme's blog entry[^] on the subject.

Re: Where can I find a table of all functions inside in kernel32.dll?

David Crow12-Sep-03 2:52

David Crow

12-Sep-03 2:52

Tommy Svensson wrote:
Now I need to know where I can find a table of all functions listed in kernel32.dll? Anyone?

Depends.exe
dumpbin /exports

are two that I know of.

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

help - mfc, and entering text

lxxrya00112-Sep-03 0:14

lxxrya001

12-Sep-03 0:14

im writing a drawing app in mfc, i just want to know how to let the user add text, ..im using the the tutorial off msdn called drawcli. if anyone knows alot about this tutorial, all the help is needed, but this is more important right now
thanks Ryan

smile...its your destiny

Re: help - mfc, and entering text

valikac12-Sep-03 6:04

valikac

12-Sep-03 6:04

One solution is an edit control.

Kuphryn

Re: help - mfc, and entering text like on paint

lxxrya00112-Sep-03 11:13

lxxrya001

12-Sep-03 11:13

im looking for more like the text button on paint...ie the user clicks on the button, then clicks on a place on the drawing area and is able to write text there...then should beable to drag and drop the text if neccesary

smile...its your destiny

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