programm crashes wenn retrieving a CString - C / C++ / MFC Discussion Boards

George213-Apr-03 22:10

13-Apr-03 22:10

Hi, everyone!

I want to implement a mini-TCP protocol that can simulate
TCP's three-time shake hands method and simulate simple
"send" and "recv" method in socket programming. I want to
use raw socket but I am not sure whether there are some
alternative methods.

I just want to get simple implementions to make a concept
proof purpose of how TCP is working. Just for learning purpose.
Smile | :)

I want to know whether there are some sample codes of this
topic that I can make a reference? Must I use RAW SOCKET?
Are there some alterative methods or alternative methods?

Thanks in advance,
George

CDialog - change title

LittleYellowBird13-Apr-03 21:55

LittleYellowBird

13-Apr-03 21:55

Hi,

I need to change the title of a dialog box, this is what I have tried:-

<code>
CDlgCal dlgCal(this);
dlgCal.SetWindowText("Step to something");
if(dlgCal.DoModal()==IDOK)
{
blah blah blah .....
}
</code>

But I get this ASSERT error when it runs ....

<b>ASSERT(::IsWindow(m_hWnd));</b>
Any ideas?

Thanks.

Ali

Re: CDialog - change title

Taka Muraoka13-Apr-03 22:09

Taka Muraoka

13-Apr-03 22:09

The window hasn't been created at this point, only the object that will be managing the window.

You need to handle the WM_INITDIALOG message and call SetWindowText() then.

Software is everything. It also sucks. Charles Fishman [^]

Awasu 1.0.2 (beta)[^]: A free RSS reader with support for Code Project.

Re: CDialog - change title

Cedric Moonen13-Apr-03 22:10

Cedric Moonen

13-Apr-03 22:10

Yes it's because your window doesn't exist when you call the SetWindowText function. It's better to change the text in the OnInitDialog() overloaded member function.

Re: CDialog - change title

peterchen13-Apr-03 22:12

peterchen

13-Apr-03 22:12

You have to do the SetWindowText inside the OnInitDialog (or later)...

The problem with Modal Windows dialogs is the Win32 Window is created & destroyed in DoModal(), i.e. it does not exist before the call.
Since MFC is supposed to be a "light wrapper", it doesn't do the same level of abstraciton as .NET or (shudder) VB.

"Der Geist des Kriegers ist erwacht / Ich hab die Macht" StS

sighist | Agile Programming | doxygen

Re: CDialog - change title

Rage13-Apr-03 22:12

Rage

13-Apr-03 22:12

The assertion comes because you try to set the text before the dialog is created with DoModal(), so the dialog has no handle, and the API function fails.

To do it properly, go in the CDlgCal::OnInitDialog() (Override the WM_INITDIALOG message if you do not have that function present in the class browser), and put your code in this function. i.e. :

... CDialog::OnInitDialog(...bla...)
{
...    
 SetWindowText("Step to something");
...
}

~RaGE();

Re: CDialog - change title

LittleYellowBird13-Apr-03 22:22

LittleYellowBird

13-Apr-03 22:22

Thanks guys - for the replies - there are some nice expainations there. I've moved my 'SetWindowText' call and its all working fine now.

Thanks again, Ali.

Ali

programm crashes wenn retrieving a CString

Willem B13-Apr-03 21:28

Willem B

13-Apr-03 21:28

hi,

i've developed a program that puts a struct into a linked list... Wenn i put the new record into my list, and i read it after that, the program crashes(wenn getting the CString)...

the problem is that my list is not updated at all... if i read a number that is inserted with the value 3, it has the value -2421523832 wenn retreiving it...

now i want to know how to update my list, not that i don't know it at all but my way is not working.

i get the pointer(Leverancier) to my struct in the function that updates the list...

<br />
NewLeverancier = new CLeverancierStruct;<br />
NewLeverancier = Leverancier;<br />
m_LeveranciersLijst.AddTail(NewLeverancier);<br />

should this work?

[]D [] []D []

Re: programm crashes wenn retrieving a CString

Joaquín M López Muñoz13-Apr-03 23:03

Joaquín M López Muñoz

13-Apr-03 23:03

Hi Willen,

I asked this very question a couple of days ago. Didn't you undesrstand my reply? If so, I'll gladly try to make myself clearer, if you're so kind as to tell me what you didn't get.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: programm crashes wenn retrieving a CString

Willem B13-Apr-03 23:13

Willem B

13-Apr-03 23:13

well it didn't work...

i made the the struct then i send the pointer to that struct towards the function to safe it in the list... than after that i just want to put it into the linked list...

so: you say i have to do this:

<br />
<small>NewLeverancier /* witch is the new pointer */ = new CLeverancierStruct(*Leverancier /* witch is the pointer to the struct */);<br />
m_LeveranciersLijst/* witch is the list */.AddTail(NewLeverancier);</small>

[]D [] []D []

Re: programm crashes wenn retrieving a CString

Willem B13-Apr-03 23:16

Willem B

13-Apr-03 23:16

okey, i tried it one more time, and it does copy the values of the struct but the problem with the CString still remains....

[]D [] []D []

Re: programm crashes wenn retrieving a CString

Willem B13-Apr-03 23:19

Willem B

13-Apr-03 23:19

oke...

I'm getting pretty crazy here... it was all a compiler fault... i rebuilt my hole project and guess what: problem solved.... damn those debug files....

thanx for helping me out...

[]D [] []D []

Re: programm crashes wenn retrieving a CString

Iain Clarke, Warrior Programmer13-Apr-03 23:07

Iain Clarke, Warrior Programmer

13-Apr-03 23:07

You need to give us some more information. From the code above it looks like you
have a pointer which you set to a new struct instance. You then point it to
a previous instance which you add to the list...? It may already be in!
You mention strings and numbers without giving us actual facts / definitions.

Try something like the following (if you like MFC):

struct Foo
{
    int nBar;
};

CTypedPtrList<CPtrList, Foo *> FooList;

Foo *f1 = new Foo;
Foo *f2 = new Foo;

f1->nBar = 3;
f1->nBar = 17;

FooList.AddTail (f1);
FooList.AddTail (f2);

Foo *f = FooList.GetHead ();
TRACE1("nBar=%i\n", f->nBar);
f = FooList.GetHead ();
TRACE1("nBar=%i\n", f->nBar);

...

There are STL equivalents to the above code, but I'm not so confident with STL to rattle
out a chunk of code off the top of my head.

Iain.

My app. under Win98? Problem with DLL's

whofmans13-Apr-03 20:40

whofmans

13-Apr-03 20:40

Hi,

I have programmed a MFC application under Win XP, and now i try to run my app on Win98.
I have copied the following files to the win98 system dir:
MFC42.dll, msvcp60.dll, msvcrt.dll

I get the following error:
The MSVCRT.DLL file is linked to missing export NTDLL.DLL RtlGetNtVersionNumbers

With Dependency Walker i see that the version of ntdll.dll not correct is for my app. When i copy a newer version of ntdll.dll to the system dir, windows doesnt start correctly.

Have i copied the wrong MSVCRT.DLL? Which DLL's do you normally use?

Thanks for helping me!

Willem

Re: My app. under Win98? Problem with DLL's

Tal Rasha's Guardianship13-Apr-03 20:46

Tal Rasha's Guardianship

13-Apr-03 20:46

you can link your program statically with MFC

Re: My app. under Win98? Problem with DLL's

whofmans13-Apr-03 21:13

whofmans

13-Apr-03 21:13

giant_hao wrote:
you can link your program statically with MFC

I have tried it, but then i get the error "Failed to create empty document", I get this error on the XP machine where i compiled the application. If i link the app normally, then the app runs fine!(under XP)

How can I modify the menus in a multi-doc application

Tal Rasha's Guardianship13-Apr-03 20:35

Tal Rasha's Guardianship

13-Apr-03 20:35

I can only get the menu of main frame by the operation of "AfxGetMainWnd()->GetMenu()",if I want to get the menu which is owned by specific document template,how can I do?

Re: How can I modify the menus in a multi-doc application

Roger Allen14-Apr-03 1:46

Roger Allen

14-Apr-03 1:46

If you have access to the CDocTemplate objects that were registered in InitInstance you can get it like this:

pTemplate->m_hMenuShared

You can get a specific doc template by iterating the CDocManager object:

CDocManger = *pDocMan = AfxGetApp()->m_pDocManager;
POSITION pos = pDocMan->GetFirstDocTemplatePosition();
while (pos)
{
CDocTemplate *pTemplate = pDocMan->GetNextDocTemplate(pos);
// make use of the pTemplate here.
}

Roger Allen
Sonork 100.10016

Were you different as a kid? Did you ever say "Ooohhh, shiny red" even once? - Paul Watson 11-February-2003

Can I design a webserivce with c#,now I want use it with c++ and webservice have session state

wxdwxd13-Apr-03 19:15

wxdwxd

13-Apr-03 19:15

I design a webservice with c#,
this webservice have some [WebMethod(EnableSession=true)]'s method
but when I use it with c++,Session lose
why?

thanks, codeproject

Updating CListCtrl using Modal CDialog

Bonnie213-Apr-03 18:06

Bonnie2

13-Apr-03 18:06

How can I pass arguments to CDialog allowing me to update a CListCtrl?

ie OnDblClick/etc, I call a modal CDialog for editing purposes, however I cannot pass arguments (ie ListItem contents to change).

Basic question - guess I am basically lost

Re: Updating CListCtrl using Modal CDialog

Ravi Bhavnani13-Apr-03 18:25

Ravi Bhavnani

13-Apr-03 18:25

You could pass the address of the list control to the dialog just before you call the dialog's DoModal(). For example:

void OnDblClick()
{
  CMyDialog dlg (this);
  dlg.m_pListCtrl = &listCtrl;
  dlg.DoModal();
}

/ravi

Let's put "civil" back in "civilization"
http://www.ravib.com
ravib@ravib.com

Convert a char* to a variant_t

Paul Farry13-Apr-03 17:10

Paul Farry

13-Apr-03 17:10

How do I convert this type.

I'm importing the CDOSYS lib, and I need to call the

pFld->put_Value(_variant_t(myconvertedtype));

the Microsoft examples use static "myaddress@something.com" , and I've not done stuff with this before.

Thanks for your help.

Re: Convert a char* to a variant_t

Brian Shifrin13-Apr-03 17:46

Brian Shifrin

13-Apr-03 17:46

CComVariant varMe("this is long ascii"String");
pFld->put_Value(varMe);

Re: Convert a char* to a variant_t

Paul Farry13-Apr-03 19:25

Paul Farry

13-Apr-03 19:25

Sorry the proper answer is:

_variant_t vtTemp;
char* szTemp;

...
...

szTemp= (char*)malloc(100);
strcpy(szTemp,"hello there");
vtTemp.SetString(szTemp);
pFld->put_Value(vtTemp);
free(szTemp);

template (ANSI compliance) question

Anonymous13-Apr-03 15:18

Anonymous

13-Apr-03 15:18

Hi,
The following compiles fine under gcc, but generates a compile error on line 2 in VC 7.0.9466 (error C2988: unrecognizable template declaration/definition)

template<class t,class="" alloc="">
template<class t1=""> // <------ error
CDSVectorBase<t,alloc>&
CDSVectorBase<t,alloc>::operator*=(const T1 &x)
{
...

Is this a problem with the C++ compiler, or is the code not ANSI compliant?

Thanks.

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