C / C++ / MFC

9-Aug-02 9:52

Hm...

- Did you placed a breakpoint on the very first statement of your listCallback?

- The cast to ACMDRIVERENUMCB for the first parameter to acmDriverEnum() should not be necessary. If the compiler complains about it, there is something wrong.

--

Daniel Lohmann

http://www.losoft.de
(Hey, this page is worth looking! You can find some free and handy NT tools there Big Grin | :-D

)

Embed a DLL. Possible?

clintsinger9-Aug-02 7:04

9-Aug-02 7:04

I have a dll that I would like to embed in an exe so I only have to distribute one file with out extracting. Is there a way to put the dll in the exe and still be able to access its functions?

Thanks,
Clint

C^hris L^osinger9-Aug-02 7:09

9-Aug-02 7:09

you could attach it to the end of the EXE and extract it at runtime, then use LoadLibrary/GetProcAddress to access the functions.

-c

Conservative:
One who admires radicals centuries after they're dead.
-- Leo C. Rosten

clintsinger9-Aug-02 7:10

9-Aug-02 7:10

I was hoping to avoid making a temp file. Are there any other ways or is this pretty much the only way?

If this is the only way how does one extract a dll? I am still learning how resources work, over and above icons. Smile | :)

C^hris L^osinger9-Aug-02 7:19

9-Aug-02 7:19

i don't think it's the only way, but it might be the only way without getting into some serious low level stuff.

you could put it in a resource, sure. that would be the most VisualStudio-friendly way. it would take about ten lines of C (plus error checking) to get the DLL out of memory and into a file - no big deal.

or, you could concatenate the DLL onto the end of the EXE, using an external app, with a length DWORD at the very end, so you know how many bytes to extract from the EXE. this method is trickier and might not be worth the effort. the resource method is probably safer.

	// find it
   HRSRC hRsrc = FindResource(hInstance, pName, "DLL");
	if (hRsrc)
	{
		// load it
		HGLOBAL hGlobal = LoadResource(hInstance, hRsrc);

		if (hGlobal)
		{
			// lock it
			BYTE *pDLL = (BYTE *)LockResource(hGlobal);
        
			DWORD dwSize = SizeofResource(hInstance, hRsrc);

... now open a file, and write the dwSize BYTEs starting at pDLL to a file.
			// clean up
			UnlockResource(hGlobal);
			FreeResource(hGlobal);
...

-c

Conservative:
One who admires radicals centuries after they're dead.
-- Leo C. Rosten

clintsinger9-Aug-02 7:26

9-Aug-02 7:26

Thanks, it doesn't look too hard.

Cheers,
Clint

Daniel Lohmann9-Aug-02 7:24

9-Aug-02 7:24

One more tip:

If you link to your dll with delay loading, you do not have to trickle with GetProcAddress() and can also easily export/import classes.

--

Daniel Lohmann

http://www.losoft.de
(Hey, this page is worth looking! You can find some free and handy NT tools there Big Grin | :-D

)

clintsinger9-Aug-02 7:25

9-Aug-02 7:25

What do mean about delay loading? Did you mean runtime linking? Any examples?

C^hris L^osinger9-Aug-02 9:03

9-Aug-02 9:03

when you build the DLL, it will build a .LIB file that contains stub function calls. if you link to this .LIB, it will handle the LoadLibrary/GetProcAddress stuff for you - you just call the DLL functions as if they were from a static library.

there may be some compiler switch necessary to enable the creation of this .LIB, but it's an easy one to find, IIRC.

-c

Conservative:
One who admires radicals centuries after they're dead.
-- Leo C. Rosten

Daniel Lohmann9-Aug-02 9:42

9-Aug-02 9:42

Link to the DLL (means link to the .lib file of the DLL) as if you want to load it implicitly. Pass a /DELAYLOAD:MyDLL.dll command line switch to the linker.

In this case the linker does not really link the dll as implicit loaded, but provides stubs for all DLL functions. Loading of the dll is delayed until the first call to the dll.

This gives you the possibility to unpack your DLL from the resource to disk before you call it first time. Otherwise (if linked implicitly) the loader will complain about "MyDLL.dll could not be found".

Delay loading is explained in detail in the VC docs and in tons of MSDN articles.

--

Daniel Lohmann

http://www.losoft.de
(Hey, this page is worth looking! You can find some free and handy NT tools there Big Grin | :-D

)

Gerald Schwab9-Aug-02 9:53

Gerald Schwab

9-Aug-02 9:53

Place your dll in with the resource data of your application. Inclusion is straightforward: place your dll in the source directory of your application, and add the following line to your .RC file:

<br />
 DATNT    BINRES  MOVEABLE PURE   "NAMEOFYOURDLL.DLL" <br />

Now, within the initialization of your application, load the resource and write it out to a temporary file.

<br />
 HRSRC   hRsrc;<br />
 HGLOBAL hResource;<br />
 DWORD   dwSize;    <br />
 LPVOID  lpvDll;<br />
 HFILE   hfTempFile;<br />
 •<br />
 •<br />
 •<br />
<br />
 hRsrc = FindResource(hInst,MAKEINTRESOURCE(DATNT),"BINRES");<br />
 <br />
 hResource = LoadResource(hInst, hRsrc);<br />
 dwSize = SizeofResource(hInst, hRsrc);<br />
 lpvDll = LockResource(hResource);<br />
     <br />
 hfTempFile = _lcreat("tempname.tmp",0);<br />
 _hwrite(hfTempFile, lpvDll, dwSize); <br />
 _lclose(hfTempFile);<br />

At this point, you'd dynamically load your dll. Once it is loaded, you can safely delete the temporary file.

Re: Embed a DLL. Possible? - And a free one

Joel Lucsy9-Aug-02 10:21

Joel Lucsy

9-Aug-02 10:21

A couple of commercial options:
Dll to Lib http://www.binary-soft.com
Fusion http://www.bit-arts.com (although I'm having problems with their site)

Joel Lucsy (jjlucsy@ameritech.net)

Neville Franks9-Aug-02 21:54

Neville Franks

9-Aug-02 21:54

Have a look at:
Packing DLLs in your EXE
http://www.windevnet.com/documents/s=7339/wdj0206c/0206c.htm

Should do precisly what you want.

Neville Franks, Author of ED for Windows. www.getsoft.com

I would like to know the instruction....

Ta_Tee4739-Aug-02 6:19

Ta_Tee473

9-Aug-02 6:19

FILE *fp;
fp = fopen(filename, mode);
fclose(fp);

There are open file but
I would like to know the instruction showing directory list.
somebody help me... thank a lots

Re: I would like to know the instruction....

C^hris L^osinger9-Aug-02 6:20

9-Aug-02 6:20

see FindFirstFile and FindNextFile

also, there are a number of classes on this site that encapsulate this operation

-c

Conservative:
One who admires radicals centuries after they're dead.
-- Leo C. Rosten

Re: I would like to know the instruction....

Ta_Tee4739-Aug-02 17:20

Ta_Tee473

9-Aug-02 17:20

I can't find FindFirstFile() and FindNextFile. Please tell me URL that is the example for FindFirstFile() and FindNextFile,.... Thank

Re: I would like to know the instruction....

C^hris L^osinger9-Aug-02 18:11

9-Aug-02 18:11

here is a C++ wrapper for FindFirstFile/FindNextFile :

http://www.codeproject.com/file/sadirread.asp

but, you can find information about these functions in the MSDN

Conservative:
One who admires radicals centuries after they're dead.
-- Leo C. Rosten

Can't figure out these compile errors.

redeemer9-Aug-02 5:58

redeemer

9-Aug-02 5:58

I'm making a list of all the available audio decoders in the system by calling acmDriverEnum, but i get some compile errors that i can't figure out how to get rid of, here's the callback prototype:

BOOL ACMDRIVERENUMCB listCallback(HACMDRIVERID hadid, DWORD dwInstance, DWORD fdwSupport);

and here's the callback function (not finished yet, i just want it to compile):

BOOL ACMDRIVERENUMCB listCallback(HACMDRIVERID hadid, DWORD dwInstance, DWORD fdwSupport)
{
	if (fwdSupport == ACMDRIVERDETAILS_SUPPORTF_CODEC)
	{
		ACMDRIVERDETAILS details;

		acmDriverDetails(hadid, &details, 0);
	}

}

these are the compile errors i get:

<br />
e:\mp3organizer\convertaudio\main.h(5) : error C2146: syntax error : missing ';' before identifier 'listCallback'<br />
e:\mp3organizer\convertaudio\main.h(5) : error C2377: 'ACMDRIVERENUMCB' : redefinition; typedef cannot be overloaded with any other symbol<br />
        e:\program files\microsoft visual studio\vc98\include\msacm.h(250) : see declaration of 'ACMDRIVERENUMCB'<br />
e:\mp3organizer\convertaudio\main.h(5) : fatal error C1004: unexpected end of file found<br />

All help appreciated, thankyou.

Re: Can't figure out these compile errors.

Daniel Lohmann9-Aug-02 6:07