C / C++ / MFC

Re: Using CoCreateInstance from C to use class in VB DLL

26-Jun-09 10:17

Actually this picture shows that there is consistency.
Can you get an instance of the object via, for instance, OleView tool?

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BeerFizz26-Jun-09 10:41

BeerFizz

26-Jun-09 10:41

This is from oleview. Not sure exactly how to use it, but this is an image from it. If you give me further instructions as to what you need to see I am sure I can provide the details, thanks for your continued help.

http://farm4.static.flickr.com/3615/3663707060_eb3f657c11_o.png[^]

Re: Using CoCreateInstance from C to use class in VB DLL

CPallini26-Jun-09 11:00

Re: Using CoCreateInstance from C to use class in VB DLL

26-Jun-09 11:00

Hey, wait a moment. The code snippet of tlh file you provided in your OP is relative to the old DLL. I hope you aren't using it.
Smile | :)

BeerFizz26-Jun-09 11:11

BeerFizz

26-Jun-09 11:11

C.Palinni, you are a genius!!! That was the issue!

D'Oh! | :doh:

You know, at some point I had thought of that but obviously screwed it up. You would think that after the multitude of compiles I've done, registers and unregisters that at some point I would have lucked on the right combination.

Thank you so much for your help, it is very much appreaciated,

Best Regards
Phil

Re: Using CoCreateInstance from C to use class in VB DLL

CPallini26-Jun-09 11:21

Refresh a form in C++ Builder

26-Jun-09 11:21

You're welcome.
Smile | :)

David21u226-Jun-09 6:12

26-Jun-09 6:12

I can not refresh the forms of my application when I execute the .exe file. Whether I click over my application then the screen seens to be frozen...same result if I do soemthing with another application like web browser...I've tried with refresh() and bringtofront() methods but it doesn't work.

I would really apreciate if someone could tell me how to keep the forms updated when it is running...

c u soon...

David

David Crow26-Jun-09 7:29

26-Jun-09 7:29

David21u2 wrote:
I would really apreciate if someone could tell me how to keep the forms updated when it is running...

How did you initially populate them?

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David21u226-Jun-09 7:42

26-Jun-09 7:42

Hi,

Thanks a lot for your help...

My issue is the following...when I'm running the .exe file... any further action I do with the mouse, lets say open another application or even click over my application cause that the screen gets frozen...i've added refresh() and Bringtofront() methods but they only work whether I run the application from the Builder IDE...

tks in advance for your help...

dg

David Crow26-Jun-09 7:47

26-Jun-09 7:47

David21u2 wrote:
...cause that the screen gets frozen...

Instead of what? Is your application doing something at that point?

David21u226-Jun-09 7:55

26-Jun-09 7:55

Yeah,

The application is a cellular networks simulator; some simulations are really heavy computationally speaking that the system I think is unable to refresh the graphical interface...but the curious thing is that only the app's screen gets frozen because the simulation itself keeps working properly; I've verified it because once the overall simulation process finishes then the application screen returns.

I've viewed some articles refering to threads but I have no idea how to use them...maybe there is another way !!

c u,
dg

David Crow26-Jun-09 7:57

26-Jun-09 7:57

David21u2 wrote:
...some simulations are really heavy computationally speaking that the system I think is unable to refresh the graphical interface...I've verified it because once the overall simulation process finishes then the application screen returns.

Put these computations into a worker thread.

David21u226-Jun-09 8:01

26-Jun-09 8:01

well,

could you give me please additional insight how to do that...i've never use such threads so a tutorial or maybe a sample file could be useful...

: )

tks
dg

David Crow26-Jun-09 8:12

26-Jun-09 8:12

See here.

David González G26-Jun-09 9:05

David González G

26-Jun-09 9:05

tks a lot for your help...I'm gonna go over that inmediately...

c u around..
dg

favorxx26-Jun-09 21:15

26-Jun-09 21:15

maybe your frequent refresh leads to the frosen, try to create a thread to refresh Smile | :)

David González G26-Jun-09 22:46

David González G

26-Jun-09 22:46

hi,

do ou have a sample code showing how to do that...
I've never used threads and I found it a bit complicated...

well, tks a lot for your help...

c u around,
dg

favorxx27-Jun-09 2:23

27-Jun-09 2:23

Multithreading Tutorial[^]

you can download the code here，although it isn't in c++ builder. It is written by api, hope it helpful.
anyway, i think the code in msdn is also valuable.

favorxx27-Jun-09 6:40

27-Jun-09 6:40

another good article for you
Threads with MFC[^]

David González G27-Jun-09 11:35

David González G

27-Jun-09 11:35

Hi,

I dont know whether there are some issues implementing threads by means of MFC in Borland C++ Builder.
I have found some problems with CWinThread class in Builder... have you some additional comments regarding it ?

tks a lot for your help...

favorxx27-Jun-09 16:59

image processing toolkits | batch image processing

27-Jun-09 16:59

MFC is a part of Visual C++, not for C++ builder, maybe the idea is useful.

If you do not want to use api or read codes in visual c++, please use TThread in c++ builder. there is an example contained in c++ builder

D:\Program Files\Borland\CBuilder6\Examples\Apps\Threads

you can file->new->others->thread object to create a new thread, See more in help file of TThread

the use of 'new'

thelonesquirrely26-Jun-09 5:40

thelonesquirrely

26-Jun-09 5:40

Hello,

I am no stranger to the idea that when you call 'new obj' it allocates dynamic memory of the heap, yada yada yada. Mainly call the corresponding 'delete obj' as is dictated by the language.

my question is with the practice of using it as you call a function:

...foo (new bar ())...

I've seen this done a lot, i was wondering why. it is a nice syntax, looks good, but seems dangerous. no handle to the obj to delete it, relying on the underlying func to take responsibility, dangerous most def. i feel like i am missing something about it. Ideas?

Re: the use of 'new'

Rajesh R Subramanian26-Jun-09 5:58

Rajesh R Subramanian

26-Jun-09 5:58

I personally have never written this kind of code, but have worked with such code. For example, such a function expects a pointer to some class object (to be on the heap). You can call the function from within a thread, and forget it. The function then guarantees clean up of the passed object.

The function code looks typically like this:

void foo(CBar *bar)
{
  if(bar == NULL)
  {
    //error handling
    return;
  }
  //use bar
  ///...
  delete bar;
}

So, you can call the function safely like: foo(new bar());

It is a crappy thing, but it's life -^ Carlo Pallini

Re: the use of 'new'

C^hris L^osinger26-Jun-09 7:51

C^hris L^osinger

26-Jun-09 7:51

i'd be very nervous if i ran across that in anything i was working on. unless the function is called DoSomethingThenDeleteTheInputObject, yes, dangerous indeed.

Re: the use of 'new'

CPallini26-Jun-09 8:54