Re: MFC question - C / C++ / MFC Discussion Boards

MemLeak12-Aug-03 6:25

12-Aug-03 6:25

Hi,

I would like to make a client/server App using C++ and visual studio.net that run on winXP.

I know that I can use CAsyncSocket and CSocket to create such an App. But I would like to know if it's the best way to do it? Is there other utilities that I can use?

Thanks for helping

Myke Big Grin | :-D

Everything's beautiful if you look at it long enough...

Re: CSocket

valikac12-Aug-03 6:51

valikac

12-Aug-03 6:51

I highly recommend raw winsock.

Kuphryn

Inserting metafiles in RichEdit

Trapper12-Aug-03 6:08

Trapper

12-Aug-03 6:08

Good day.
I've got little problem - I need to insert metafile with picture in it in to rich edit. I must do it without COM. MFC/Win API only. Does anyone knows, how to do that? Advice or piece of program would be a great help.

Trapper

program access to locked directory

IdUnknown12-Aug-03 5:31

IdUnknown

12-Aug-03 5:31

Hi Everyone,

First time poster on this site, I hope someone can help me with this problem.

Let say my program is install in C:\myprog and everytime before it exits, it writes a string to a file. It works ok because I logged in as an Admin. But, if a user logs in and doesn't have write permission, then the program cannot save data to the file in that directory when it exits. Is it possible for my program to write to the directory, even though, the user does not have the access rights? If so, how can I programmatically do it using Win32 API? Any helpful suggestions or hints would be appreciated.

It runs on WinNT with NTFS.

Thanks,

ing

Re: program access to locked directory

Steve S12-Aug-03 5:43

Steve S

12-Aug-03 5:43

There are two approaches; one, give users TCB privilege (ugh!!) so they can run the app and it can impersonate a user who has access, Not a good idea, or second, have a service running with no GUI which runs as a user who has access, and have your app talk the the service. It has permission, so it can write, user doesn't need permission.

You'd need to use something like TCP/IP or Named Pipe for communication, I guess.

Steve S

Using old Visual Studio 6 Lib/dlls

Dirk Vandenheuvel12-Aug-03 4:44

Dirk Vandenheuvel

12-Aug-03 4:44

Any problems with that in VS 2003? Some of my colleages have hinted I might have to recompile the dlls to get VS2003 compatible libs? Sounds odd to me. If so.. what has changed and why?

MFC question

Beer2612-Aug-03 4:28

Beer26

12-Aug-03 4:28

how do you get the 3d inner border style of of the CMainFrame window to disappear?

I don't want my child view to look sunken into the frame. I tried &= ~WS_ with several styles on OnCreate, but nothing has worked so far.

tried all the
lpCreateStruct->dwExStyle &= ~WS_
plus I tried the
lpCreateStruct->style &= ~WS_

Re: MFC question

Nish Nishant12-Aug-03 4:39

Nish Nishant

12-Aug-03 4:39

It is the not the CMainFrame window that is responsible for the 3D border. It is the inner CView derived window that is responsible. In the CView derived class's OnInitialUpdate() remove the WS_EX_CLIENTEDGE style using ModifyStyleEx

Nish

Extending MFC Applications with the .NET Framework [NW] (My book with Tom)
Summer Love and Some more Cricket [NW] (My first novel)
Shog's review of SLASMC [NW]
Come with me if you want to live

Re: MFC question

Beer2612-Aug-03 5:52

Beer26

12-Aug-03 5:52

aha! thank you

ODBC

Ortie12-Aug-03 4:16

Ortie

12-Aug-03 4:16

Hi, I need to get list of databases on server thru ODBC.
I can do it by native query for specific database server,
but I need to do that by ODBC function, to work on any server.
I can get list of tables thru SQLTables function, but how can
I get a list of databases?

Is there a way to do that?

Re: ODBC

basementman12-Aug-03 4:24

basementman

12-Aug-03 4:24

Below is a code snippet that will help demonstrate how to get the list of catalogs for a given DSN and load them into a combo box:

CComboBox *pCB = (CComboBox *)GetDlgItem(IDC_CODEGENTBL_DB);
pCB->ResetContent();

DBConnection *pDBConn = &(((CodeGenOpts *)GetParent())->m_oDBConn);
DBStatement oStmt(pDBConn);
oStmt.AllocStatement();

int iDBCount = 0;
CString cDBName;
SQLRETURN iResult = SQLTables(oStmt.GetStmtHdl(),
                               (unsigned char *)"%", 1,
                               (unsigned char *)"",0,
                               (unsigned char *)"",0,
                               (unsigned char *)"",0);
if (iResult == SQL_SUCCESS || iResult == SQL_SUCCESS_WITH_INFO)
  {
    while (oStmt.FetchNext())
      {
        cDBName = oStmt.GetString(1);
        if (!cDBName.IsEmpty())
          {
            pCB->AddString(cDBName);
            iDBCount++;
          }
      }

    oStmt.EndSQL();
  }

onwards and upwards...

Help on DLLs

Radha Nair12-Aug-03 4:03

Radha Nair

12-Aug-03 4:03

Hi,

I have a class that is exported by using dllexport. Now, I wish to use the methods of the class. If I use dllimport, I have to include the .h files and add all the .lib files to start using the methods of the exported class. Now, can I achieve the same using Loadlibrary()? If yes, how can I do it and is it a better option to use Loadlibrary()? Any problems that you foresee with this? Please suggest.

thanks.

Re: Help on DLLs

Chris Meech12-Aug-03 5:01

Chris Meech

12-Aug-03 5:01

Radha Nair wrote:
If yes, how can I do it and is it a better option to use Loadlibrary()?

I have not seen any examples of doing this with C++ classes. So I'm thinking that no you can't do it. I'm sure someone will try to proove me wrong, though Smile | :)

In the case of the first method of including the .h and .lib files, the compiler and linker will be doing 'things' that won't get done when you use the second method. You can probably get the second method to work, if you know all the 'things' the compiler and linker do for you and then emulate that some how in code that you incorporate with your LoadLibrary calls. Can it be done, maybe, but I haven't seen an example so I don't think it can.
One option is to write some plain 'C' functions that provide an interface to the C++ class, and use these instead of the C++ methods.

Chris Meech

"what makes CP different is the people and sense of community, things people will only discover if they join up and join in." Christian Graus Nov 14, 2002.

Oh and for those that ask programming questions in the lounge. Seek the truth here[^].

Re: Help on DLLs

Nish Nishant12-Aug-03 5:53

Nish Nishant

12-Aug-03 5:53

Chris Meech wrote:
I'm sure someone will try to proove me wrong, though

Not trying to prove anything. But maybe something like this can be done?

//header file
class ExportedClass
{
public:
    ExportedClass();
    ~ExportedClass
    void Abc();
};

ExportedClass* GetExportedClass()
{
    return new ExportedClass();
}

Now in the main exe, do something like :-

GETEXPORTEDCLASS func = GetProcAddress(...,"GetExportedClass");
ExportedClass* pec = (func)();
pec->Abc();

This is untested code and it might not work for various reasons (member name mangling for one) but it's worth a try. If this is a stupid idea, please forgive my relative ignorance in such matters Smile | :)

Nish

Extending MFC Applications with the .NET Framework [NW] (My book with Tom)
Summer Love and Some more Cricket [NW] (My first novel)
Shog's review of SLASMC [NW]
Come with me if you want to live

Re: Help on DLLs

Chris Meech12-Aug-03 6:11

Chris Meech

12-Aug-03 6:11

Thanks, Nish. That's what I was sugggesting as an alternative. Except that I think you also have to have an exported function to access the Abc() function. In your example the Abc method wont be exported. And not to mention that there are a whole lot of issues with new/delete, memory leaks, name mangling and such. It can get quite ugly, to say the least.

Another option to consider as well, is to use COM to 'export' the class. But that's for another day. Big Grin | :-D

Chris Meech

"what makes CP different is the people and sense of community, things people will only discover if they join up and join in." Christian Graus Nov 14, 2002.

Oh and for those that ask programming questions in the lounge. Seek the truth here[^].

Re: Help on DLLs

Radha Nair12-Aug-03 6:22

Radha Nair

12-Aug-03 6:22

Really appreciate all the help. thanks both you guys.

Nishant, I understood your method. It's real clean. But the problem is that Iam not developing the exported class. It has already been developed and closed. They have just used dllexport to export it. So, considering the situation, do I have any choice other than going for implicit linking?

Any other method of explicit linking without touching the header/cpp file of the class that is being exported?

Sorry if Iam asking for too much! Smile | :)

Re: Help on DLLs

igor196012-Aug-03 10:51

igor1960

12-Aug-03 10:51

DelayLoad...

"...Ability to type is not enough to become a Programmer. Unless you type in VB. But then again you have to type really fast..."
Me

Re: Help on DLLs

Rick York12-Aug-03 12:55

Rick York

12-Aug-03 12:55

The trouble with using LoadLibrary with classes is the name mangling done by the compiler/linker make it very difficult to access members of the class. I believe that it is generally easier to use the implicit linking method for classes.

An alternative (and one I have used) is to make a layer of C functions to access the class. You can write an initialize function to construct, a terminate function to destroy, and then pass in a pointer to the object to functions that access the methods of the object. This takes a little work but is easy to implement.

The Ten Commandments For C Programmers

Re: Help on DLLs

Radha Nair13-Aug-03 3:13

Radha Nair

13-Aug-03 3:13

Thanks all you guys. Every line was highly informative and helped me a lot.

Thanks again,
Radha Nair

Context menu on ActiveX control

Ed K12-Aug-03 3:40

Ed K

12-Aug-03 3:40

I've build a small MFC ActiveX control that needs a context menu. The context menu appears on the however none of the menu items are active. How do I get the activeX control to manage them?

ed

I need help in timers or conversions

S^nyp12-Aug-03 3:37

S^nyp

12-Aug-03 3:37

I want to make the user of the program be able to type in a number and let the timer count to the number but I keep on getting the wrong output. I put a int and string variable.
if(m_iCount == m_sCountTo) Help Confused | :confused:

[It is possible to represent everything in this universe by using 0 and 1]
I'm going to live forever or die trying.

Re: I need help in timers or conversions

David Crow12-Aug-03 3:48

David Crow

12-Aug-03 3:48

You can't compare an int to a string (unless the appropriate overloaded operators have been implemented).

Re: I need help in timers or conversions

Anonymous12-Aug-03 4:24

Anonymous

12-Aug-03 4:24

if(m_iCount == atoi(m_sCountTo)) ...

Re: I need help in timers or conversions

S^nyp12-Aug-03 6:28

S^nyp

12-Aug-03 6:28

THANK YOU!!!! IT WORKS!!!!
Laugh | :laugh:

[It is possible to represent everything in this universe by using 0 and 1]
I'm going to live forever or die trying.

Re: I need help in timers or conversions

PremL12-Aug-03 5:26

PremL

12-Aug-03 5:26

I suggest you keep the counter and the target value in integer format. This way you can compare them easily and perform a lot of other operations like increment easily.

You’ll need to convert from string to int, when the user enters the value. For display purposes you can either format the integer into a nice looking string, or display it directly.

Lorenz Prem
Microsoft Corporation

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