C / C++ / MFC

Re: How to remove help file from make ? ( MFC VC6.0)

19-Apr-07 6:12

Select Dependencies from the Project menu.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Vaclav_19-Apr-07 7:09

Vaclav_

19-Apr-07 7:09

Found it!
I had a wrong include path for afxhelp.hm and my ;Phack in renaming the directory acually masked the real error Roll eyes | :rolleyes:

message.

Avoid multiple applications calling the same DLL [modified]

Samaya K.B.19-Apr-07 4:38

Re: Avoid multiple applications calling the same DLL

19-Apr-07 4:38

Hi!
I have developed a VC++ Dll. This Dll resides in a common location accessible to 2-3 applications (VC++ applications). Can anyone please tell me how can i limit only one application to call the DLL at a time.
My requirement is only one VC++ application should load the DLL at the same time. No two applications should load the DLL at same time.
This is very urgent. Any help is greatly appreciated.

-- modified at 10:52 Thursday 19th April, 2007

Rajesh R Subramanian19-Apr-07 5:07

Rajesh R Subramanian

19-Apr-07 5:07

That sounds odd. One of the primary advantages of using DLLs is that more than one application can use it at a time. Why do you want to do that?

Re: Avoid multiple applications calling the same DLL

Samaya K.B.19-Apr-07 18:22

Re: Avoid multiple applications calling the same DLL

19-Apr-07 18:22

My Dll communicates with external customised hardware and gets the data and the processed result is sent back to the client application.In the mean time if another application calls the same exported function of the dll, i will not be able send the accurate results(the hardware will not respond untill prevoius commands are serviced) to any of the client application.

CPallini19-Apr-07 5:13

CPallini

19-Apr-07 5:13

You can use some info shared among DLL instances to prevent multiple processes to access the DLL functions at the same time. A quite similar problem was neatly addressed in this article [^] (see Code Details section).

Hope that helps.

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: Avoid multiple applications calling the same DLL

cmk19-Apr-07 14:21

cmk

19-Apr-07 14:21

If it's an explicit load then wrap LoadLibrary with a named mutex.
If it's an implicit load then wrap all access points with one or more named muticies.

...cmk

Save the whales - collect the whole set

Re: Avoid multiple applications calling the same DLL

Samaya K.B.19-Apr-07 18:48

Re: Avoid multiple applications calling the same DLL

19-Apr-07 18:48

i understand the logic.
Can you please send me some sample snippets if you have any? I have not worked on mutex yet and feeling difficult to understand from articles and MSDN.
My applications will be explicitly loading the Dll's.
So i understand i need to wrap the LoadLibraray() fnction in my Client application by mutex. But how will the other application know about this?
Mutex should be defined where?

cmk19-Apr-07 20:08

cmk

19-Apr-07 20:08

Read: http://msdn2.microsoft.com/en-us/library/ms682411.aspx[^]

In your other reply you say it is one function you need to protect.
Something like this should work (you should add appropriate error checking):

void  YOUR_EXPORT_API  YourFunc ( void ) 
{
    HANDLE  mtx = CreateMutex(NULL, FALSE, "YourUniqueMutexName");
    WaitForSingleObject(mtx, INFINITE);
 
    // do your normal function stuff
 
    ReleaseMutex(mtx);
    CloseHandle(mtx);
}

If you can you may want to move the CreateMutex/CloseHandle code to the app init/term functions.

What happens in the above code is that the first app to call YourFunc creates a new mutex. Any other apps (or threads in the creating app) that call YourFunc will get a handle to the existing mutex when they call CreateMutex. After that the Wait function allows only one thread (across all apps) to execute the protected code at a time.

...cmk

Save the whales - collect the whole set

Re: Avoid multiple applications calling the same DLL

Samaya K.B.19-Apr-07 21:06

Get information about free disk space?

19-Apr-07 21:06

Thanks much for your help and Code!! Smile | :)

My problem is solved.
I read MSDN and learnt a new concept of using Mutex!!

Thanks again!!

bosfan19-Apr-07 4:00

bosfan

19-Apr-07 4:00

Hello,
how to to get information about how many disk is available,
and about all partitions if there more then one!?
What functions to use for that?

regards
termal

David Crow19-Apr-07 4:20

19-Apr-07 4:20

termal wrote:
What functions to use for that?

How about GetDiskFreeSpace()?

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

bosfan19-Apr-07 4:52

bosfan

19-Apr-07 4:52

Hello,
thank you for your info, that is what i mean!

regards
termal

ThatsAlok2-May-07 23:40

ThatsAlok

2-May-07 23:40

termal wrote:
GetDiskFreeSpace

better use GetDiskFreeSpaceEx

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

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bosfan3-May-07 0:24

bosfan

3-May-07 0:24

Hi,
thanks for info!

termal

About tab control.

iayd19-Apr-07 3:43

iayd

19-Apr-07 3:43

Hi I am using a Tab control in my project but when I change the color of dialog box a gray tab control seemed vary bad.How can I change the color of tab control?I couldn't find this subject in my book and also my knowledge is not enough to understand the articles about owner-drawn tab controls in this site.I do not want any gray area in my dialog box.How can I do that?And if you know where can I find a source about that subject in internet,please tell it to me.
Thanks

Re: About tab control.

Alexandre GRANVAUD20-Apr-07 2:03

Alexandre GRANVAUD

20-Apr-07 2:03

try to create your own class derived from CTabCtrl
then overload WM_ERASEBACKGROUND message
and in this message you can set the default background color of your control

How to fill a ellipse

jerome_data19-Apr-07 3:23

jerome_data

19-Apr-07 3:23

How do you fill a ellipse on a CDC without Floodfill?

thanks

David Crow19-Apr-07 3:32

19-Apr-07 3:32

Select a different-colored brush into the DC before drawing. There's also FillRect().

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

bob1697219-Apr-07 3:38

bob16972

19-Apr-07 3:38

Can you use FillRect() for an Ellipse or was that a morning glitch? I'm having those myself this morning. Smile | :)

David Crow19-Apr-07 3:49

19-Apr-07 3:49

bob16972 wrote:
Can you use FillRect() for an Ellipse...

I guess not. I was just assuming you'd give it a starting point somewhere within the shape and it would fill until it reached the edges. I guess that's what FloodFill() is for! Blush | :O

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: How to fill a ellipse [modified]

jerome_data19-Apr-07 3:57

jerome_data

19-Apr-07 3:57

thanks

yes it's very easy to fill a ellipse with current selected brush.
in fact my problem it's to do a pie chart. I draw a pie chart with 3 parts. How i can fill with colore each parts??

David Crow19-Apr-07 4:18

19-Apr-07 4:18

jerome_data wrote:
I draw a pie chart with 3 parts. How i can fill with colore each parts??

Can you call Pie() three times, using a different brush each time?

[edit]
I just tried this and it worked fine.
[/edit]

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne