Unmanaged pointer in a managed class? (C3160) - C / C++ / MFC Discussion Boards

nlecren13-Apr-04 9:58

13-Apr-04 9:58

i have the following problem, if i declare a variable in a local function and then assign a value in a try block under release min dependency the value is corrupt or the same as it was before the try block upon entering the catch. Please what am i doing wrong?? The code is below:

STDMETHODIMP CCMI_BioWrapper::QueryTemplate(BSTR Badge,BSTR *Response)
{
AFX_MANAGE_STATE(AfxGetStaticModuleState())

int nRetCode;
CString strVal;

nRetCode = 0;

try
{
nRetCode = 99;
return S_OK;
}
catch(...)
{
// I would expect nRetCode to be 99 here
// however it is always 0, unless i do a debug build
// then it always works

strVal.Format("Q0 %d",nRetCode);
*Response = strVal.AllocSysString();

return S_OK;
}
}

Check the Status of a URL

Renjith Ramachandran13-Apr-04 8:20

Renjith Ramachandran

13-Apr-04 8:20

how can i check the status of a URL, like http://www.codeproject.com
is active / down , Winsock or any other ..????

I want to change Myself..Can u help me? Smile | :)

Re: Check the Status of a URL

David Crow13-Apr-04 8:31

David Crow

13-Apr-04 8:31

How about InternetCheckConnection()?

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Check the Status of a URL

Renjith Ramachandran13-Apr-04 8:43

Renjith Ramachandran

13-Apr-04 8:43

Great..Thankyou

I want to change Myself..Can u help me? Smile | :)

Re: Check the Status of a URL

basementman13-Apr-04 9:50

basementman

13-Apr-04 9:50

You can look at this example prog: [^]

onwards and upwards...

Re: Check the Status of a URL

Renjith Ramachandran13-Apr-04 21:01

Renjith Ramachandran

13-Apr-04 21:01

I need the API, not the exes..
D'Oh! | :doh:

I want to change Myself..Can u help me? Smile | :)

Re: Check the Status of a URL

basementman14-Apr-04 3:56

basementman

14-Apr-04 3:56

Here is the source for the app (bear in mind that this is just a quicky example app and not necessarily coded well Unsure | :~

) [^]

onwards and upwards...

Unmanaged pointer in a managed class? (C3160)

mccoyn13-Apr-04 8:19

mccoyn

13-Apr-04 8:19

I am porting an old project to be able to use .Net. There is a struct type that needs to be used by an old library written in C and a new class library written with .Net. When I try to have a pointer to this struct as a member of a managed class I get the following error:

error C3160: 'piData' : cannot declare interior __gc pointer or reference as a member of 'PatInfo'

Here is the struct definition in a header file used in both projects:

typedef struct _reportFull{
ReportHeader * header;
ReportStruct * st;
ReportAngio * angio;
ReportNonSaved * ns;
} ReportFull;

Here is part of the PatInfo class definition from another header file:

__gc class PatInfo {
public:
PatInfo();
~PatInfo();

ReportFull __nogc *piData;
ReportFull __nogc *temp_data;
ReportFull __nogc *defaults_reference;

UserControl* dlg;
};

The error occurs when I try to make a derived class from PatInfo. I suspect that it would occur any time I use PatInfo.

Anyone know of a way to use pointers to unmanaged types within a managed class?

Stack overflow problem

Anonymous13-Apr-04 8:16

Anonymous

13-Apr-04 8:16

I keep getting a stack overflow error when running a multiple threaded app. I thought the OS allocated 1 meg and grew the stack when one uses createthread with zero for the stack size param. How do you use the param? I set the param to a more than sufficient value, but it changed nothing. Do I need set anything else? I noticed setting the stack commit/reserve in the proj setting fixed the issue. Why did this work. Any suggestions.

Re: Stack overflow problem

Blake Miller14-Apr-04 5:53

Blake Miller

14-Apr-04 5:53

If you are writing a Win32 application and you use Viusual C++ and you make calls to some standard C library functions, then you should start your thread with beginthreadex instead of CreateThread. It initializes thread local storage for certain standard library functions. If you called one of these from your thread, you might have blown the stack. Otherwise, check for excessive recursion in your code. Maybe you just luckily made the stack large enough not to blow in this particular instance. I have used file and directory search code from threads, as a recursivee example, and I have yet to ever have to adjust any stack size thread related parameters away from their defaults.

Tree Control Questions.

Maximilien13-Apr-04 7:47

Maximilien

13-Apr-04 7:47

I have a tree control in which I have a couple of top level items ( hParent == TVI_ROOT ).

I need to be able to select items from the different subtrees, so I'm using CMultiTree ( from codeguru ).

The question is :

Is there a way to search/select/manipulate all subtrees at the same time, with a single "root" item ?

I can search each subtree with a simple recursive method, but I need to search each sub tree individually; not a big deal, but if I need to add a new subtree, I will need to add it to each operation that will scan the different trees ( add, remove, select, modify ... )

I wanted to put each sub-trees under a single "root" item to do this, but the boss doesn't like it. Frown | :(

Maybe I got things wrong ... any suggestions ?

Thanks.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: Tree Control Questions.

Iain Clarke, Warrior Programmer13-Apr-04 23:23

Iain Clarke, Warrior Programmer

13-Apr-04 23:23

It may be my imagination, but you've answered your own question. Each top level item is a child of
the TVI_ROOT "item".

So if you have a HTREEITEM SearchChildren (HTREEITEM hSearchRoot) funtion, just feed it TVI_ROOT
as the search root.

Iain.

ps. SearchChildren was an example name...

2 ListBoxes 1 scrollbar

doctorpi13-Apr-04 7:35

doctorpi

13-Apr-04 7:35

Hi guys
There is an easy way to manage the following?.
I have 2 list controls one above the other and what I want is that when I move the horizontal scrollbar of the above listcontrol the down scrollbar move like it was linked. Is this possible easily?
Best Regards
Doc

Re: 2 ListBoxes 1 scrollbar

basementman13-Apr-04 10:04

basementman

13-Apr-04 10:04

Yes, but you'll have to write all of the scroll sync code.

onwards and upwards...

Re: 2 ListBoxes 1 scrollbar

doctorpi14-Apr-04 3:26

doctorpi

14-Apr-04 3:26

Where can I start to take a look about scroll sync?
Thanks
Doc

Re: 2 ListBoxes 1 scrollbar

basementman14-Apr-04 4:07

basementman

14-Apr-04 4:07

For starters, you can look at the MFC file ViewScrl.cpp to see how to handle scroll messages. Then, you would need to scroll the second control (via ScrollWindow or equivalent) when the first is scrolled.

onwards and upwards...

Re: 2 ListBoxes 1 scrollbar

doctorpi14-Apr-04 6:38

doctorpi

14-Apr-04 6:38

Incredible but true!!!!
http://www.codeproject.com/listctrl/synchscroll.asp#xx128601xx
Nice job.
Thanks anyway.
Doc

RegEnumValue problems.

HAHAHA_NEXT13-Apr-04 7:29

HAHAHA_NEXT

13-Apr-04 7:29

I wrote my code in VB(It is hell but i had not choice), but it does not work.
I keeps returning error 234 (ERROR_MORE_DATA). But i have a 12 Kb buffer, which means the problems is something else.

Please Help.
I am already 3 hours in this &^&%&%. Mad | :mad:

Re: RegEnumValue problems.

David Crow13-Apr-04 8:34

David Crow

13-Apr-04 8:34

HAHAHA_NEXT wrote:
I keeps returning error 234 (ERROR_MORE_DATA). But i have a 12 Kb buffer, which means the problems is something else.

You failed to indicate what API you are using that is producing this "error." In any case, it's obvious that a 12KB buffer is insufficient. Try a larger number.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: RegEnumValue problems.

Navin13-Apr-04 10:09

Navin

13-Apr-04 10:09

ERROR_MORE_DATA is not really an error. It simply means that there are more values to enumerate. RegEnumValue does not enumerate *all* values, you give it a counter, and it enumerates one at a time. For instance (yes, this is C++ code, but you can figure out the algorithm):

DWORD error;
DWORD index = 0;
TCHAR nameBuff[1024];
TCHAR valueBuff[1024];
DWORD nameBuffSize, valueBuffSize;
DWORD type;
do
{
  nameBuffSize = valueBuffSize = 1024;
  error = ::RegEnumValue(hSectionKey, index, nameBuff, nameBuffSize,
    0, &type,(BYTE *)valueBuff, &valueBuffSize);

  if(error == ERROR_SUCCESS || error == ERROR_MORE_DATA)
  {
    // do something with the enumerated value
  }
  index++;
} while(error == ERROR_SUCCESS || ERROR == ERROR_MORE_DATA);

Sometimes I feel like I'm a USB printer in a parallel universe.

Re: RegEnumValue problems.

HAHAHA_NEXT13-Apr-04 10:10

HAHAHA_NEXT

13-Apr-04 10:10

I think i found it. Stupid vb does not understand NULLS.

Re: RegEnumValue problems.

HAHAHA_NEXT13-Apr-04 10:12

HAHAHA_NEXT

13-Apr-04 10:12

I think i found it. Stupid vb does not understand NULLS.

error = ::RegEnumValue(hSectionKey, index, nameBuff, nameBuffSize, 0, NULL,NULL,NULL);

Does not work with VB (&^%$^^&^%&) Mad | :mad:

.
Thank you all. I changed my code and it works now.

HELP Please!!!

sekeya13-Apr-04 7:03

sekeya

13-Apr-04 7:03

Is there a way to conver a C++ program into MFC? IF so how do I go about doing it!!

Re: HELP Please!!!

David Crow13-Apr-04 8:34

David Crow

13-Apr-04 8:34

Not automatically.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)