C / C++ / MFC

Manny thanks ! it is works !!! extra last question

21-Oct-01 10:51

My fault too. I only gave you half a story. ATL doesn't support CEdit natively. There are two ways you can get a CEdit control in an ATL dialog. The easiest way is to use the WTL headers that come with the platform sdk or secondly you can read the following knowledge base item http://support.microsoft.com/support/kb/articles/Q223/4/39.ASP

Michael Smile | :)

Re: Try CWindow!

Masaaki Onishi21-Oct-01 13:36

Masaaki Onishi

21-Oct-01 13:36

Hello, the codegurus around the world.

Try CWindow to deal with Edit box! Cool | :cool:

USER_CONVERSION;
CWindow wnd;
CComBSTR bstr;

   wnd = GetDlgItem (IDC_EDIT1);
   wnd.GetWindowText (&bstr);
   wnd.SetWindowText (_T("I like ATL!"));

Have a nice day!

-Masaaki Onishi-

mimi21-Oct-01 23:22

mimi

21-Oct-01 23:22

The guide of you (mainly of christian and Masaaki ) was excellent,

Now I have the last question for this project (so I hope):

Which files of the ATL DLL project I need to provide for Delphi except MyAtl.DLL ???

Because in client program in VC++ I need also :MyATL.h and MyATL_i.c.

Smile | :)

Daed21-Oct-01 1:08

Daed

21-Oct-01 1:08

I am trying to register my ActiveX control, but it gives me an error of failing under WinNT because i am using an API that needs a special DLL to exist under windows directory and it works only in Win2000 and Win98 platforms. How can I make my control register under WinNT without the need of having this DLL under the system directory? Confused | :confused:

Daed

Michael P Butler21-Oct-01 3:05

21-Oct-01 3:05

What is the name of the special DLL? If you want the code to work on WintNT you will have to avoid calling the unsupported functions. I usually do this by have a pre-processor define for NT and compiling a special version of my application for NT.

Michael Smile | :)

Daed21-Oct-01 3:51

Daed

21-Oct-01 3:51

The DLL is Msimg32.dll, i need it because i am using AlphaBlend function in one of my control's property. Is there anything i can do at registry time to solve this problem?

Daed

Michael Dunn21-Oct-01 8:17

Michael Dunn

21-Oct-01 8:17

You need to link dynamically to the DLL import. Load the DLL with LoadLibrary() and try to get the function's address with GetProcAddress(). If that succeeds, then use the pointer GetProcAddress() returns to call the API. If that returns NULL, then the API is not available.

--Mike--
http://home.inreach.com/mdunn/
"....." -- Silent Bob
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Re: About DLL initialization

Daed22-Oct-01 6:28

Daed

22-Oct-01 6:28

Can you give me an example of how i can do this? or may be a link where i can find more explanation about the subject? Thank you Smile | :)

Daed

About DLL initialization

Maer72721-Oct-01 1:05

Maer727

21-Oct-01 1:05

- What means the initialization of a DLL? The function DllMain, or the function LoadLibrary?

- My problem arises from the following taken from MSDN (Ti: DllMain)

You must not call LoadLibrary in the entry-point function, because you may create dependency loops in the DLL load order. This can result in a DLL being used before the system has executed its initialization code.

- After reading the codes, I think LoadLibrary is not the initialization of a Dll.

- But what means the initialization of a DLL?

- Can you help?

Thanks,
Maer

Steen Krogsgaard21-Oct-01 23:23

Steen Krogsgaard

21-Oct-01 23:23

Hi Maer,

When you wan't to use a DLL in your app you have to load it into your process address space first. This is done by the function LoadLibrary. When LoadLibrary executes it first maps the DLL into the process' address space (this means that if the DLL is already used by another app it is not re-loaded from disk, but setup so the your process can see it in it's own address space). Then it's initialization time! LoadLibrary calls the DllMain function located in the DLL with the dwReason parameter set to DLL_PROCESS_ATTACH. After the DllMain function returns LoadLibrary calls it once again, this time with dwReason set to DLL_THREAD_ATTACH. If both these calls to DllMain succeeds then LoadLibrary returns to your app, giving you the handle to the newly loaded - and initialized - DLL.

The problem you're referring to is if you put another LoadLibrary call in your DllMain function. Say your DLL (DllA) is dependent on a second DLL, DllB, which in turn is dependent on DllA again. In DllA's DllMain function a call to LoadLibrary(DllB) is issued. In DllB's DllMain function a function in DllA is executed. Since DllA is loaded there's no problem in calling the function, but since the DllA is not yet initialized there may be some data that the called function uses that is not set up properly (e.g. MFC state data Wink | ;-)

.

To summarize: LoadLibray performs two tasks: One is to do the physical loading of the DLL (loading from disk, linking all the exported functions), the other is to initialize the DLL. Initialization consists of calling DllMain twice, once with DLL_PROCESS_ATTACH and once with DLL_THREAD_ATTACH.

Cheers
Steen.

"To claim that computer games influence children is rediculous. If Pacman had influenced children born in the 80'ies we would see a lot of youngsters running around in dark rooms eating pills while listening to monotonous music"

a very very simple question about DllMain

Maer72721-Oct-01 0:47

Maer727

21-Oct-01 0:47

- The following sentence if taken from MSDN (ti: DllMain)
Access to the entry point is serialized by the system on a process-wide basis.

- I do not know what means "serialized" and "process-wide basis" here.

- Can you show me an example?

Thanks,
Maer

Re: a very very simple question about DllMain

Steen Krogsgaard21-Oct-01 23:33

Steen Krogsgaard

21-Oct-01 23:33

This means that any call to DllMain is completed before a new call can be processed.

Imagine you have two threads in your app. Both threads call LoadLibray(YourDLL). If these calls occur concurrently then you could imagine the following scenario: Thread A calls LoadLibrary which calls DllMain with a DLL_PROCESS_ATTACH. During the execution of DllMain the thread is preemted by Thread B, that also calls LoadLibrary which also calls DllMain with a DLL_PROCESS_ATTACH. Now you have two threads that are executing the same piece of code in DllMain concurrently, and this means you'd have to be careful when writing the code to avoid any concurrency issues. What MDSN tells you is that Windows will halt the call from Thread B until the call from Thread A has finalized.

Cheers
Steen.

P.S. Your mail adress still bounces. I get a "Domain not found" error ?!?

"To claim that computer games influence children is rediculous. If Pacman had influenced children born in the 80'ies we would see a lot of youngsters running around in dark rooms eating pills while listening to monotonous music"

Distributing a DLL

Peter Liddle21-Oct-01 0:34

Peter Liddle

21-Oct-01 0:34

Hey Guys

I am looking for a quick and easy way to distribute a windows explorer extension DLL. All that really needs to happen is that it is copied to a specified folder then registered.

Has anyone got any ideas
Cheers
Peter

Michael P Butler21-Oct-01 3:11

21-Oct-01 3:11

Well a good old fashioned batch file might work.

echo off
copy mydll.dll c:\windows\system /y
regsvr32 mydll.dll

I do this a lot when I'm distributing applications that are used in house. Just run the batch file and the dll is installed.

Michael Smile | :)

Michael Dunn21-Oct-01 8:21

Michael Dunn

21-Oct-01 8:21

ewww, never copy anything into \windows\system. Take an extra 10 seconds of typing and make a directory under \Program Files (that's what Program Files is there for).

--Mike--
http://home.inreach.com/mdunn/
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Michael P Butler21-Oct-01 8:22

21-Oct-01 8:22

sorry, I was just using it as an example copy command. It was the first directory that popped into my head.

Michael Smile | :)