C / C++ / MFC

Re: Adding a int array inside CStringArray

19-Dec-11 2:12

You need to rethink your design; don't mix different types in this way, it will likely lead to problems in the future.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Albert Holguin19-Dec-11 3:12

Albert Holguin

19-Dec-11 3:12

+5, don't store an int array in a CStringArray

Re: Adding a int array inside CStringArray

Richard MacCutchan19-Dec-11 6:00

Adapter Classes for using C++ library through JNI

19-Dec-11 6:00

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

pandit8419-Dec-11 0:26

pandit84

19-Dec-11 0:26

Hi ,
I have created C++ library(3 dlls) and I am using these library in my Java UI through JNI. In my JNI I am modifiying jobjectArray i.e. adding data inside my jobjectArray and returning it from JNI. Now my problem is if in future my C++ library changes I will have to change my JNI code. What should I do to 'tune' my JNI so that it will change with minimum impact. Does it require Adapter classes or wrapper clases. Any information on this will help me. Thanks

Re: Adapter Classes for using C++ library through JNI

CPallini19-Dec-11 3:12

19-Dec-11 3:12

[Byrne voice]
Well we can't predict the future
But we're trying to do the best that we can
[/Byrne voice]

I suppose 'the best you can' here is: "follow the KISS principle, keep it simple".

Since you cannot predict the future changes, make your overall design simple and well documented.

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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

CWinThread

columbos1492718-Dec-11 22:45

columbos14927

18-Dec-11 22:45

In the main thread of my app i do some work and once in a while i create another helper thread to do some job using: AfxBeginThread function which returns me a CWinThread object reference.

But before i will create once again the helper thread i have to be sure that the previous is done.

Now im using the CEvent object to signal from the helper thread that he is done but my app crashes sometimes.

Can i use the CWinThread object to find out whether the previous thread is done?

Thanks.

Re: CWinThread

CPallini18-Dec-11 23:12

18-Dec-11 23:12

Have a look at MSDN documentation: "Multithreading: Terminating Threads"[^].
The "Retrieving the Exit Code of a Thread" section gives all info you need (read carefully the steps needed in order to retrieve the exit status of a CWinThread).

Re: CWinThread

Albert Holguin19-Dec-11 3:15

Albert Holguin

19-Dec-11 3:15

Think you probably need to figure out the cause of the crash (that's your main issue), but you can also use the main thread handle in the CWinThread to "wait on" (WaitForSingleObject).

Save As Image

john563218-Dec-11 22:08

john5632

18-Dec-11 22:08

Can I save drawn rectangle into an bmp image?

CPallini18-Dec-11 22:18

18-Dec-11 22:18

Yes, you may do, see here for a recipe[^], also have a look at this useful sample code[^].

john563218-Dec-11 23:44

john5632

18-Dec-11 23:44

But how to save drawn rectagle into an image?

CPallini18-Dec-11 23:51

18-Dec-11 23:51

Drawn rectangle (drawn everything) is in 'the content' of current paint HDC (or CDC if you are using MFC), hence, for instance, inside the WM_PAINT message handler you may copy current paint HDC content into image HDC, using BitBlt function).

john563219-Dec-11 0:24

john5632

19-Dec-11 0:24

Thanks for reply, but the link you suggested doing the same thing, I am confused to save image on specific path?????

CPallini19-Dec-11 0:33

copying from large buffer to smaller

19-Dec-11 0:33

Well, once you have the bits copied to the bitmap then you may save the bitmap itself. You may use, for instance CImage class (see, for instance "Save CBitmap to File"[^] or, if you want to go to the metal, see "Storing an Image"[^]

VCProgrammer18-Dec-11 21:21

VCProgrammer

18-Dec-11 21:21

Hi all,

i have two char buffers char a[1000],char a1[100].

i want to copy 100 value from a to a1, but everytime the index where we should start copying is different i.e. sometime it should start copying from a[100], other time from a[268].

For Copying from one buffer to another we can use function memcpy_s but it starts copying from zero.

Is there any alternate for this.

Thanks in advance

Re: copying from large buffer to smaller

CPallini18-Dec-11 21:52

Re: copying from large buffer to smaller

18-Dec-11 21:52

Just continue using memcpy_s starting from the right address, e.g.:

C++

errno_t result;
result = memcpy_s(a1, sizeof(a1), &a[268], sizeof(a1));

VCProgrammer19-Dec-11 1:04

VCProgrammer

19-Dec-11 1:04

thanks its done

Re: copying from large buffer to smaller

CPallini19-Dec-11 1:24

image processing toolkits | batch image processing

19-Dec-11 1:24

You are welcome.

Thread sync

columbos1492718-Dec-11 3:28

columbos14927

18-Dec-11 3:28

Im using CCriticalSection object as a parameter to CSingleLock.

When i try to create the lock object i get the:"Access violation reading location".

Why could it be?

Thnks

Re: Thread sync

C^hris L^osinger18-Dec-11 4:24

C^hris L^osinger

18-Dec-11 4:24

can you show us your code?

Re: Thread sync

columbos1492718-Dec-11 4:35

columbos14927

18-Dec-11 4:35

Hello,
I think i know what my mistake was.

I used the same CCriticalSection as a parameter to different CSingleLock objects to synchronize different resources.
I have four threads two of them use one mutual queue and the other two use other queue so i used the same CCriticalSection object as a parameter to two CSingleLocks.
Now i defined seperate lock for each queue and it works fine.

Thanks any way

clipboard and file

Member 820281618-Dec-11 0:37

Member 8202816

18-Dec-11 0:37

Hi! I would like to put a file in the clipboard like when you click on a file and you copy, how can I do that?
I tried in c++ with setclipboarddata() with filename (49158) and filenameW (49159) format but doesn't work, inside the clipboard there are some other formats that I don't know. The complete list of the format is:
49161, 49268, 15, 49349, 49340, 49158, 49159, 49171.

Re: clipboard and file

Richard MacCutchan18-Dec-11 1:19

18-Dec-11 1:19

I've no idea what all these numbers are supposed to mean, but I would suggest you copy the path of the file into the clipboard rather than its content. Perhaps if you show the actual code you are trying to use, someone can help you.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Re: clipboard and file

Member 820281618-Dec-11 1:54

Member 8202816

18-Dec-11 1:54

Ok, thank you, actually to put in the clipboard the path is what I want to do, not the content of the file, in other word I want to do the same thing that you do on windows when you select a file and click on copy.

The code:
(filename format 49158)

char path[]="C:\\file.txt";
int size=strlen(path)+1;
hglbDato = GlobalAlloc(GMEM_MOVEABLE,size);
PVOID pv = (PVOID) GlobalLock(hglbDato);
memcpy(pv,path,size);
GlobalUnlock(hglbDato);
SetClipboardData(49158,hglbDato);

and I do the same for format filenameW (49159) but instead to use a char array I use a wchar array and wcslen() instead of strlen(). Obviously the file.txt exists.

Re: clipboard and file

Richard MacCutchan18-Dec-11 4:28