C / C++ / MFC

21-Jul-07 23:11

I am trying to figure out how I can best move an existing mfc dialog app into a dll and then be able to launch it from a console based application when needed.

I understand the basics of dll importing / exporting and how to create and use a dll

I just want to know how do I get the app now insider a dll to initialize and show itself? basically the mfc is an observer type object and once created and made visible I can grab it's interface and start providing it data to output in the window.

Yours Truly, The One and Only!

#realJSOP22-Jul-07 0:16

#realJSOP

22-Jul-07 0:16

Just write a console app to launch your existing app. There's no need to put it into a DLL.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

DevMentor.org22-Jul-07 8:32

22-Jul-07 8:32

Not going to work in my case.

This is going to be a part of a 3rd party tool I am working on, I rather that other developers link to the dll and be able to use it without any gui or mfc knowledge.

Yours Truly, The One and Only!

Mark Salsbery22-Jul-07 9:15

22-Jul-07 9:15

This may help - Kinds of DLLs[^]

Particularly the sections related to regular DLLs linked with MFC.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

DevMentor.org22-Jul-07 9:35

22-Jul-07 9:35

Thanks Mark, Big Grin | :-D

I already know about DLLs... I am just trying to contain all the MFC GUI logic inside a dll and then have a simple way to evoke the MFC Dialog based app I created with the Wizard. I would also like to be able to call this GUI from a console based app provided all the relevant mfc / windows definitions are included.

I know it's possible after all you can throw up a message box from a console app Big Grin | :-D

Yours Truly, The One and Only!

Mark Salsbery22-Jul-07 9:39

22-Jul-07 9:39

Right - that's why I said look into those specific links.

MFC apps may require certain objects to exist and certain initialization to be done, depending on
how you're using it. That link is a starting point to those details.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

DevMentor.org22-Jul-07 9:55

22-Jul-07 9:55

LOL are we going to play message Tag =P

I am familiar with that section of the DLL in MSDN, which basically is talking about the types of DLL, but I will take another look at it.

FYI: I was able to convert the mfc app into a dll package and have it build cleanly and spit out the dll and lib files for linking. I have also been able to link the mfc dll from my console based app and have it load the dll into the process space.

What do I need to do to create an instance of my MFC app which is deriver from CWinApp and have it initialized to be able to show my Dialog based window? All the logic I have that I need is inside the dialog based window class..so do I even need to worry about CWinApp, is there a way just to create a modeless window that has it's own message loop?

Yours Truly, The One and Only!

Mark Salsbery22-Jul-07 10:05

22-Jul-07 10:05

I'll rip the relevent portions for you:

"A regular DLL, statically linked to MFC, has the following requirements:
This type of DLL must instantiate a class derived from CWinApp.
This type of DLL uses the DllMain provided by MFC. Place all DLL-specific initialization code in
the InitInstance member function and termination code in ExitInstance as in a normal MFC
application.
Even though the term USRDLL is obsolete, you must still define "_USRDLL" on the compiler command
line. This definition determines which declarations is pulled in from the MFC header files"

"Regular DLLs must have a CWinApp-derived class and a single object of that application class, as
does an MFC application. However, the CWinApp object of the DLL does not have a main message
pump, as does the CWinApp object of an application.

Note that the CWinApp::Run mechanism does not apply to a DLL, because the application owns the
main message pump. If the DLL opens modeless dialogs or has a main frame window of its own, the
application's main message pump must call a routine exported by the DLL that in turn calls the
CWinApp::PreTranslateMessage member function of the DLL's application object."

"A regular DLL, dynamically linked to MFC has the following requirements:
These DLLs are compiled with _AFXDLL defined, just like an executable that is dynamically linked
to the MFC DLL. But _USRDLL is also defined, just like a regular DLL that is statically linked to
MFC.

This type of DLL must instantiate a CWinApp-derived class.
This type of DLL uses the DllMain provided by MFC. Place all DLL-specific initialization code in
the InitInstance member function and termination code in ExitInstance as in a normal MFC
application.

Because this kind of DLL uses the dynamic-link library version of MFC, you must explicitly set
the current module state to the one for the DLL. To do this, use the AFX_MANAGE_STATE macro at
the beginning of every function exported from the DLL.

Regular DLLs must have a CWinApp-derived class and a single object of that application class, as
does an MFC application. However, the CWinApp object of the DLL does not have a main message
pump, as does the CWinApp object of an application.

Note that the CWinApp::Run mechanism does not apply to a DLL, because the application owns the
main message pump. If your DLL brings up modeless dialogs or has a main frame window of its own,
your application's main message pump must call a DLL-exported routine that calls
CWinApp::PreTranslateMessage.

Place all DLL-specific initialization in the CWinApp::InitInstance member function as in a normal
MFC application. The CWinApp::ExitInstance member function of your CWinApp derived class is
called from the MFC provided DllMain function before the DLL is unloaded."

Is that better? Poke tongue | ;-P

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

DevMentor.org22-Jul-07 10:17

22-Jul-07 10:17

yes that is better Poke tongue | ;-P

... LOL

Hopefully I can display the dialog window without too much work!

Yours Truly, The One and Only!

DevMentor.org23-Jul-07 10:39

Re: how to get Cwnd object

23-Jul-07 10:39

This was a lot simpler that I first thought Laugh | :laugh:

When I rediscovered AfxSetResourceHandle() everything came together!

Yours Truly, The One and Only!

how to get Cwnd object

Max++21-Jul-07 21:46

Max++

21-Jul-07 21:46

How can I get CWnd object from dialog base and SDI project;

Thanks

#realJSOP22-Jul-07 0:27

#realJSOP

22-Jul-07 0:27

Every CWnd-based object (dialogs, views, controls, etc) can be cast to a CWnd*.

Externally, you can do this:

CWnd* pWnd = (CWnd*)myDialog;

Internally you can do this:

CWnd* pWnd = this;

Re: how to get Cwnd object

ThatsAlok22-Jul-07 17:56

ThatsAlok

22-Jul-07 17:56

Max++ wrote:
How can I get CWnd object from dialog base and SDI project;

AfxGetMainWnd

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief

Re: how to get Cwnd object

Hamid_RT31-Jul-07 19:48

Hamid_RT

31-Jul-07 19:48

Sometime you can use of this.

WhiteSky

error C2061: syntax error : identifier 'search'

jt900021-Jul-07 18:31

jt9000

21-Jul-07 18:31

Hi, I have a function called "search" which is a program that searches MySQL database for a match.
I get "error C2061: syntax error : identifier 'search' " when I try to compile the whole program.

My function declaration is the following:

int search(int, char*);

I call the function by:

search(argc, *argv[]);

I do not quite understand the int argc, char* argv[] that's pass to the function, but they were from the MySQL examples my function is based on. I still get the same error message when I take them out.

THANKS IN ADVANCE for the help.

The entire funtion looks like:

int search(int argc, char* argv[])
{
;
MYSQL *hnd=NULL; // mysql connection handle
const char *sinf=NULL; // mysql server information

hnd = mysql_init(NULL);
if (NULL ==
mysql_real_connect(hnd,SERVER_NAME,DB_USER,DB_USERPASS,DB_NAME,0,NULL,0))
{
fprintf(stderr,"Problem encountered connecting to the %s database on
%s.\n",DB_NAME,SERVER_NAME);
}
else
{
fprintf(stdout,"Connected to the %s database on %s as user
'%s'.\n",DB_NAME,SERVER_NAME,DB_USER);
sinf = mysql_get_server_info(hnd);

if (sinf != NULL)
{
fprintf(stdout,"Got server information: '%s'\n",sinf);
showTables(hnd);
showContents(hnd,TABLE_OF_INTEREST);
}
else
{
fprintf(stderr,"Failed to retrieve the server information string.\n");
}

mysql_close(hnd);
}

return 0;
}

void showTables(MYSQL *handle)
{
MYSQL_RES *result=NULL; // result of asking the database for a listing
of its tables
MYSQL_ROW row; // one row from the result set

result = mysql_list_tables(handle,NULL);
row = mysql_fetch_row(result);
fprintf(stdout,"Tables found:\n\n");
while (row)
{
fprintf(stdout,"\t%s\n",row[0]);
row = mysql_fetch_row(result);
}
mysql_free_result(result);

fprintf(stdout,"\nEnd of tables\n");

return;
}

void showContents
(
MYSQL *handle,
const char *tbl
)
{
MYSQL_RES *res=NULL; // result of querying for all rows in table
MYSQL_ROW row; // one row returned
char sql[1024], // sql statement used to get all rows
commastr[2]; // to put commas in the output
int i,numf=0; // number of fields returned from the query

sprintf(sql,"select * from %s",tbl);
fprintf(stdout,"Using sql statement: '%s' to extract all rows from the
specified table.\n",sql);

if (!mysql_query(handle,sql))
{
res = mysql_use_result(handle);
if (res)
{
numf = mysql_num_fields(res);
row = mysql_fetch_row(res);
fprintf(stdout,"Rows returned:\n\n");
while (row)
{
commastr[0]=commastr[1]=(char)NULL;
for (i=0;i

Re: error C2061: syntax error : identifier 'search'

Abhijeet Pathak22-Jul-07 4:41

Abhijeet Pathak

22-Jul-07 4:41

int search(int, char*); states that it will take an integer argument and a single string.
where as char *argv[] is a collection of strings (rather an array of strings).
You are getting error because you are passing array of strings to a function which expects a single string.

You can instead try the following:

<br />
int iCnt;<br />
for (iCnt=0; iCnt<argc; iCnt++)<br />
{<br />
    search(iCnt, argv[iCnt]);<br />
}<br />

How to get all the export functions of a dll

kcynic21-Jul-07 17:37

kcynic

21-Jul-07 17:37

A dll file ,i only could see four export functions,these are DllCanUnloadNow,DllGetClassObject,DllRegisterServer and DllUnregisterServer using Dependency Walker. I think it is a COM component.
How could I find the other content so that I can use the dll(or COM component)?

Thanks

Michael Dunn21-Jul-07 18:00

Michael Dunn

21-Jul-07 18:00

Those are the four exports you usually see on DLLs that are only used as COM servers. You can try #importing the DLL, if it has a type library, the compiler can generate wrapper classes for you that may give a hint as to what's in the DLL.

--Mike--
Visual C++ MVP Cool | :cool:

LINKS~! Ericahist | PimpFish | CP SearchBar v3.0 | C++ Forum FAQ

Dunder-Mifflin, this is Pam.

kcynic21-Jul-07 18:53

kcynic

21-Jul-07 18:53

In fact,there are somethings good,so i want to reuse it.
Of course,i should know what the content it export.
If I only use #import import the dll library,I remain don't know how to use the library,is it right?

DevMentor.org21-Jul-07 23:48

21-Jul-07 23:48

you will need to register the DLL using regsvr32, use oleview to get an idea about what interfaces are available, this tool come with visual studio

you should know how to create and use a com object Laugh | :laugh:

Yours Truly, The One and Only!

ThatsAlok22-Jul-07 17:56

ThatsAlok

22-Jul-07 17:56

kcynic wrote:
How could I find the other content so that I can use the dll(or COM component)?

OleView Application will Help

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief

Don't understand what's required in order to use unmgd c++ class in c# app - help?

kcynic22-Jul-07 18:23

kcynic

22-Jul-07 18:23

Thank you every one.
I will have a try,but if there is some other problems I hope I can gain some help here agin.
Thanks again

sherifffruitfly21-Jul-07 10:32

sherifffruitfly

21-Jul-07 10:32

Hi all,

I've got the source code and compiled binary for a c++ class library, and I'd like to be able to instantiate & use the class in a c# application. What's the simplest way to do this? I've looked up resources, but they all appear to me more complicated than my basic level of understanding of MS C++ will allow to be helpful to me.

Can someone point me to a very simple recipe (and hopefully simple explanation too) on how to turn this unmanaged class into one which c# can use?

Also, will there be issues about "return data type matching" between c++ and c#?

Thanks,

cdj

Re: Don't understand what's required in order to use unmgd c++ class in c# app - help?

Mark Salsbery21-Jul-07 10:51