Re: Can anybody tell me why? - C / C++ / MFC Discussion Boards

Tomasz Sowinski30-Jul-01 8:49

30-Jul-01 8:49

Maybe MFC sample DLGCBR32 will help? It demonstrates the dialog-based app with a toolbar. It uses WM_IDLEUPDATECMDUI and ON_UPDATE_COMMAND_UI handlers.

Tomasz Sowinski -- http://www.shooltz.com

help! message handling in general

27-Jul-01 10:45

Help! This is sort of related your problem of a window receiving a message but not processing it. The message maps I created for the class inherited from CView don't work.

The COpenGLView class I describe below is the toplevel window when the application is run. I know that the window receives the message I send it from another application because I monitor the messages sent to that window using Spy++. But it doesn't seem to be processing that message I send it, even though it receives the message...

help... i'm at wits' end. thanks. Confused | :confused:

<br />
/***********************<br />
OpenGLView.h<br />
*********************/<br />
#define UM_MYMESSAGE	WM_USER + 1<br />
...<br />
class COpenGLView : public CView<br />
{<br />
...	<br />
DECLARE_DYNCREATE(COpenGLView)	<br />
DECLARE_MESSAGE_MAP()<br />
...	<br />
void OnMyMessage (WPARAM wParam, LPARAM lParam );<br />
...<br />
}<br />
/***********************<br />
OpenGLView.cpp<br />
*********************/<br />
#include "OpenGLView.h"<br />
<br />
BEGIN_MESSAGE_MAP(COpenGLView, CView)	<br />
ON_MESSAGE( UM_MYMESSAGE, OnMyMessage )<br />
END_MESSAGE_MAP()<br />
<br />
...<br />
<br />
void COpenGLView::OnMyMessage (WPARAM wParam, LPARAM lParam )<br />
{   <br />
::MessageBox( NULL, _T("Hi"), _T("Hi"), MB_OK);<br />
}<br />
<br />
/***************************************<br />
In another project altogether...<br />
*************************************/<br />
#define UM_MYMESSAGE	WM_USER + 1<br />
...<br />
<br />
// Called when button "Foo" is pressed <br />
void CMyDialog::OnButtonFoo() <br />
{	<br />
HWND hwnd_lh = ::FindWindow( NULL, _T("OpenGL") ); // the CEAGameView window is labeled "OpenGL" <br />
::SendMessage( hwnd_lh, UM_MYMESSAGE, (WPARAM) NULL, (LPARAM) NULL );<br />
}<br />

Re: help! message handling in general

Neville Franks27-Jul-01 12:40

Neville Franks

27-Jul-01 12:40

I can't see how COpenGLView can be your top level window. This is a view within your MainFrame. It would seem to me that your other app is sending to the MainFrame window not the View.

Neville Franks, Author of ED for Windows
www.getsoft.com

Re: help! message handling in general

august27-Jul-01 13:04

august

27-Jul-01 13:04

ooops, you're completely right. Dead | X|

i should have my wrists slapped for not taking the time out to really understand the document/view architecture. i am now rerouting the message to COpenGLView, which is a child of the the mainframe window. thanks.

Thanks for all the help :)

Derek Lakin31-Jul-01 2:53

Derek Lakin

31-Jul-01 2:53

Thanks for everyone's help with this one. Finally it works Smile | :)

The end result was to handle WM_KICKIDLE, as my parent dialog wasn't receiving any WM_IDLEUPDATECMDUI messages. I then had to use SendMessage to pass the message on to all of the child dialogs because PostMessage didn't work.

Can anybody help me?

26-Jul-01 22:52

Hi,

I'm a begginer in C++ and I've a problem allocating memory on the heap and I'd really appreciate if somebody could help me.

Here's the code:

MyStructure *pMyStructure = new MyStructure[ELEMENTS];
// Do some code here
delete [] MyStructure

Where MyStructure is a structure I've created and I want an array of it.
The problem is when I try to delete the structure, I get some messages like that:

Expression:_BLOCK_TYPE_IS_VALID(pHead->nBlockUse)

I don't understand what is happening and what I'm doing wrong. Could anybody tell it to me?

Can anybody tell me why?

26-Jul-01 23:26

Hi again,

Since I posted the message I've found what was happening:

MyStructure *pMyStructure = new MyStructure[ELEMENTS];
// Do some code here
delete [] MyStructure;

What whas happening is that somewhere in
//Do some code here
I had a loop where I increased pMyStructure (pMyStructure++) to access the elements of the array. I've found that if before deleting the array I decrease the pointer until it's initial value, I can delete it without any error.

What I'd like to know is why it happens and if I'm doing right accessing the array that way.

Thanks in advance,

Re: Can anybody tell me why?

C^hris L^osinger27-Jul-01 1:50

C^hris L^osinger

27-Jul-01 1:50

the problem is that a pointer is just a number. there's nothing else to it. and when you change its value, it no longer points to the same thing.

but when you delete something, the pointer you're deleting must point to the start of the block of memory that was actually allocated - which it probably won't be, if you've changed the pointer's value.

so, do something like:

MyStructure *pMyStructure = new MyStructure[ELEMENTS]; 
// Do some code here 
MyStructure *pCur = pMyStructure;
pCur++;... whatever you want.

// delete the original
delete [] MyStructure;

-c

------------------------------
Smaller Animals Software, Inc.
http://www.smalleranimals.com

Re: Can anybody tell me why?

27-Jul-01 1:56

Thanks, I've understand it!

Item, GetItem...

Gérald Mercet26-Jul-01 22:39

Gérald Mercet

26-Jul-01 22:39

I would like to know how i could use in ADO, the method Item or GetItem, when i don't want to specify the name of the field i need but its index
How could i do that?

thanks in advance

gerald

Confused | :confused:

Saving for the future

Joe Moldovan26-Jul-01 22:36

Joe Moldovan

26-Jul-01 22:36

Because of the pace of work I get very little chance to look at this discussion group but it's one of the single most useful resorces on the Net and has never let me down.

Does anyone know if there is any CD archive of the past threads or are there any plans to capture one. I would be willing to pay for such a service and I'm sure many others would be as well. I don't mean any fancy searchable database or anything like that - just a copy of the whole discussion group. It would be one of the most valuable resources for me.

Have Fun!

Re: Saving for the future

Paolo Messina27-Jul-01 10:33

Paolo Messina

27-Jul-01 10:33

It'd be better to post this message in th Suggestions Forum, so Chris can see it Wink | ;)

need an advice...

26-Jul-01 22:05

i am making an app using the CFtpConnection and CInternetSession classes.
when i try to connect (or any ther action to the server), my program freezes, the window is not refreshed, how can i solve this? by creating a new thread? if yes than who do i do that?

and another quastion: on my dialog i have a TListCtrl wich shows the files on the server, how can i extract their icons fot the display?

thanks

TrichEdit

26-Jul-01 22:01

Hello

How can i inseret different font color lines to a TRichEdit?
some code will be great!

thanks

Re: TrichEdit

Paolo Messina27-Jul-01 10:27

Paolo Messina

27-Jul-01 10:27

I think that people here are using VC++, not C++ Builder.
Or did you mean CRichEdit ?

Anyway, I can't help, sorry! Smile | :)

Paolo

Problem around usage of RUNTIME_CLASS

EiSl26-Jul-01 21:42

EiSl

26-Jul-01 21:42

Hello all...

I'm lost... maybe because I'm searching to deep, but anyway. My collega came to me for help, but unfortunately.. Confused | :confused:

Let's take a look to this sample:

class CMySystems{
  // Anything
};

class CMyDetails{
  // Anything
};

void xxx::SomeMethod( void )
{
  ...
  // Sets up the (docking) TabControlBar
  m_wndMyCtrlBar.AddView("Systems", RUNTIME_CLASS(CMySystems));
  m_wndMyCtrlBar.AddView("Details", RUNTIME_CLASS(CMyDetails));  
  ...
}

Now the problem:
In the class CMySystems I want to be able to use methods from the class CMyDetails.

How can I at runtime pass the 'this' pointer of the CMyDetails class to the CMySystems?

Thanks in advance,

EiSl

Re: Problem around usage of RUNTIME_CLASS

Tomasz Sowinski27-Jul-01 4:43

Tomasz Sowinski

27-Jul-01 4:43

It seems that TabControlBar creates CMySystems and CMyDetails objects for you - one of the CRuntimeClass responsibilities is creating CObject-derived objects. If your question is how to get actual object after it is created by CRuntimeClass, the answer is: you depend on TabControlBar. This class should give you access to its views; I'd expect something like TabControlBar::GetFirstView/GetNextView. Since it's 3rd party class, I can't help you futher.

Tomasz Sowinski -- http://www.shooltz.com

NT management

Serge A. Zhirko26-Jul-01 21:27

Serge A. Zhirko

26-Jul-01 21:27

Hi!

Does anyone know, how can I create new NT user?

Thanks a lot.

Re: NT management

Jon Sagara26-Jul-01 22:07

Jon Sagara

26-Jul-01 22:07

Look up the NetUserAdd() function in MSDN.

Jon Sagara

"Left-handed nunchakus!"

How declare a Function with 8 Inputs and 4 Outputs ??

youssef26-Jul-01 20:59

youssef

26-Jul-01 20:59

Hi,

I would like to create a function with 8 Inputs and the result is in 4 Ouputs.

How can I declare it?

Best Regards

youssef

Re: How declare a Function with 8 Inputs and 4 Outputs ??

26-Jul-01 21:50

Hi Are you really shure that you want to have that many in and outputs in one function? Maybe the function is doing too much and you should consider splitting it up in several functions.
Else, while a function only can return one value you have to get the result through the parameters in the function using pointers or references. Something like: myFunction(in1,in2,in3,in4,in5,in6,in7,in8,*out1,*out2,*out3,*out4).

/Per

Re: How declare a Function with 8 Inputs and 4 Outputs ??

fantastic_mr_fox26-Jul-01 23:21

fantastic_mr_fox

26-Jul-01 23:21

the other asy is to group your values into structures or clases (input and output)

then it's easy...

COutputInfo DoSomeCalcs( CInputInfo in )
{
:
} Smile | :)

Preprocessor defines and MFC

Serge A. Zhirko26-Jul-01 19:42

Serge A. Zhirko

26-Jul-01 19:42

Hi!
Does anyone know, how to determine (until preprocessor defines) the app use MFC or not, if included support MFC in static library ?

Re: Preprocessor defines and MFC

Michael Dunn26-Jul-01 20:26

Michael Dunn

26-Jul-01 20:26

When using the DLL version of MFC, the symbol _AFXDLL is defined. When using the statically-linked version, it's not defined.
As for whether MFC is being used or not... it looks like you can check for __AFX_H__, which is defined when afx.h is #include'd.

--Mike--
http://home.inreach.com/mdunn/
"Make sure that if you are using a blow torch that you don't set anything on fire."
-- Chris Maunder

How to Inport A Resource and its Class

nulldreamer26-Jul-01 16:46

nulldreamer

26-Jul-01 16:46

Hi,
I know how to import say a dialog box from another project,
project->add to project->files->the_resource_file.rc
But don't know how to import that dialog's class from the other project.
I want to be able to import a dialog box and it's class, so I wont have to recreate member variables and all the rest of them things. How can I go about that?
Thanks

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