Re: how to set radio button to be checked? - C / C++ / MFC Discussion Boards

Jason Henderson13-May-02 17:18

13-May-02 17:18

Check if RegCreateKeyEx returns ERROR_SUCCESS and close the key only if it is successful.

if (RegCreateKeyEx(...) == ERROR_SUCCESS)
{
// your code here
RegCloseKey(...);
}

Like it or not, I'm right.

simple MFC Q- about inheritance

spoongirl13-May-02 8:26

spoongirl

13-May-02 8:26

is there some mysterious unwritten law against inheriting INDIRECTLY from MFC classes?

i'm having all sorts of trouble trying to do something very simple. here is an example of my woe:

I'd like to create my own Wizard property sheet class, derived from CPropertySheet. ok, well- that's all fine and good, as long as I use the class that inherits directly from CPropertySheet. but try to add another layer, and forget it. will NOT compile.

same thing now happening with CPropertyPage. I'm trying to make a bunch of pages for my wizard, and they share common characteristics. seems like the textbook case of where to use a base class. I'd like to make my base class, WizardPage (or whatever) inherit from CPropertyPage. then all of my actual pages inherit from WizardPage.

no matter what i try, this will not compile. if i try to use one of the child classes, it says "base class undefined" or something. trust me, i included the right headers. Wink | ;)

i would be forever grateful to anyone who can explain why this is happening.

~L

Re: simple MFC Q- about inheritance

Bill Wilson13-May-02 10:01

Bill Wilson

13-May-02 10:01

There is nothing wrong with what you are trying to do. There is no limitation of inheritance from MFC classes or CPropertySheet.

Sorry, but the problem is in your code.

here is a sample:

[ccode]
// Derived.cpp: implementation of the CDerived class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "RegHelper.h"
#include "Derived.h"
#include "MyPropSheet.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CDerived::~CDerived()
{

}
CDerived::CDerived(UINT nIDCaption, CWnd* pParentWnd, UINT iSelectPage)
:CMyPropSheet(nIDCaption, pParentWnd, iSelectPage)
{
}

/////////////////////////////////////////////////////////////////////////////
// CMyPropSheet

class CMyPropSheet : public CPropertySheet
{
DECLARE_DYNAMIC(CMyPropSheet)

// Construction
public:
CMyPropSheet(UINT nIDCaption, CWnd* pParentWnd = NULL, UINT iSelectPage = 0);
CMyPropSheet(LPCTSTR pszCaption, CWnd* pParentWnd = NULL, UINT iSelectPage = 0);

// Attributes
public:

// Operations
public:

// Overrides
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CMyPropSheet)
//}}AFX_VIRTUAL

// Implementation
public:
virtual ~CMyPropSheet();

// Generated message map functions
protected:
//{{AFX_MSG(CMyPropSheet)
// NOTE - the ClassWizard will add and remove member functions here.
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};

[/ccode]

Hope this helps,
Bill

Re: simple MFC Q- about inheritance

spoongirl14-May-02 5:38

spoongirl

14-May-02 5:38

thanx for the response. i did in fact find the problem not too long after i posted the question.

the main thing i've found is that you have to be really careful about the Class Wizard. it's helpful, but only up to a point. (like, up to the point where you add another level of inheritance to your class heirarchy- eg, if i were to make a class inherit from your CMyPropSheet)

anywyas, thanx again for taking hte time to help out.
Smile | :)

~L (spoongirl)

how to set radio button to be checked?

pnpfriend13-May-02 8:14

pnpfriend

13-May-02 8:14

how to set radio button to be checked?

i want to checked radio button when user go to a menu bar, action menu, and choose menu item named check.

Re: how to set radio button to be checked?

Wes Jones13-May-02 8:25

Wes Jones

13-May-02 8:25

Check out:

BOOL CheckDlgButton(
HWND hDlg, // handle to dialog box
int nIDButton, // button identifier
UINT uCheck // check state
);

or

void CWnd::CheckDlgButton( int nIDButton, UINT nCheck );

--------
CheckDlgButton(IDC_MY_RADIO_BTN, BST_CHECKED);

HTH,
-Wes

Sonork ID 100.14017 wtheronjones

Re: how to set radio button to be checked?

Jason Henderson13-May-02 8:44

Jason Henderson

13-May-02 8:44

If you are using a CButton, use SetCheck(1) to check or SetCheck(0) to uncheck.

Like it or not, I'm right.

Re: how to set radio button to be checked?

redeemer13-May-02 9:17

redeemer

13-May-02 9:17

You can use the BM_SETCHECK message:

SendMessage( 
  (HWND) hWnd,              // handle to destination window 
  BM_SETCHECK,              // message to send
  (WPARAM) wParam;          // check state
  (LPARAM) lParam;          // not used; must be zero
);

Re: how to set radio button to be checked?

Michael Dunn13-May-02 10:26

Michael Dunn

13-May-02 10:26

CheckRadioButton() is the best way - it checks one button and unchecks all others in the group.

--Mike--
Buy me stuff!
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My really out-of-date homepage
Big fan of Alyson Hannigan and Jamie Salé.
Sonork - 100.10414 AcidHelm

class fstream and dll

Dan Verret13-May-02 8:05

Dan Verret

13-May-02 8:05

I have created a dll in which I use the following linkage interface:

#ifdef CONSOLEDLL_EXPORTS
#define CONSOLEDLL_API __declspec(dllexport)
#else
#define CONSOLEDLL_API __declspec(dllimport)
#endif

every classes have been declared like this:

class CONSOLEDLL_API CCenteredStepEdger : public CStepObject{
friend CONSOLEDLL_API ostream& operator <<( ... );
friend CONSOLEDLL_API istream& operator >>( ... );
...

and some of the classes use fstream type variables:

fstream m_File;

when I compile the project, I have the following warning:

class 'fstream' needs to have dll-interface to be used by clients of class 'CCenteredStepEdger '

How should I specify the dll-interface for the fstream variables???

Thanks

Daniel Verret

Detecting multiple partitions on the same hard drive

Wes Jones13-May-02 7:19

Wes Jones

13-May-02 7:19

I'd like to know how I can find out if two drive letters refer to partitions on the same hard drive.

I'm working on a database backup utility, & I want to discourage users from selecting the same physical hard drive for their backups as the hard drive where their 'live database' is running.

ie: If "C:\LiveDatabases" and "D:\My Backups" are actually located on the same physical harddrive(on different partitions), I'd like to know how to determine this info.

Thanks!

Wes

Sonork ID 100.14017 wtheronjones

Re: Detecting multiple partitions on the same hard drive

redeemer13-May-02 9:43

redeemer

13-May-02 9:43

Try checking out this site: http://www.users.intercom.com/~ranish/part/primer.htm

Re: Detecting multiple partitions on the same hard drive

Wes Jones13-May-02 13:16

Wes Jones

13-May-02 13:16

Thanks for the informative link, but I'm looking for API's that I'd be able to use to figure this out.

Thanks!
-Wes

Sonork ID 100.14017 wtheronjones

Re: Detecting multiple partitions on the same hard drive

Jason Henderson13-May-02 17:21

Jason Henderson

13-May-02 17:21

Not sure if this will give you the right info, but check out the GetVolumeInformation function on MSDN and the lpVolumeSerialNumber parameter.

Like it or not, I'm right.

Re: Detecting multiple partitions on the same hard drive

Wes Jones13-May-02 18:03

Wes Jones

13-May-02 18:03

I thought might be it, but I hadn't tested it yet...
thanks!
Wes

Sonork ID 100.14017 wtheronjones

ISAPI Filter and FTP

Ed K13-May-02 6:45

Ed K

13-May-02 6:45

Can an ISAPI Filter be used to catch content being sent to an FTP site?

Thanks,

ed

'Love is an obsessive delusion that is cured by marriage.' Dr. Karl Bowman

Re: ISAPI Filter and FTP

Bill Wilson13-May-02 10:03

Bill Wilson

13-May-02 10:03

No. I believe ISAPI only filters HTTP requests.

Hope this helps,
Bill

Re: ISAPI Filter and FTP

Ed K13-May-02 10:14

Ed K

13-May-02 10:14

Thanks...that is what I thought.

ed

'Love is an obsessive delusion that is cured by marriage.' Dr. Karl Bowman

Get IP address programatically ?

dlhson13-May-02 6:24

dlhson

13-May-02 6:24

How can I get IP address of any computers that connect to my computer through a CSocket variable ?

Ex: My computer run a program as a server, using a CSocket variable, listen to connection.
Client run a program connect to server at port 0 by a CSocket variable.
I want to get IP address of the client !
How to ?

Hung Son
A Vietnamese student
i-g.hypermart.net
dlhson2001@yahoo.com

Re: Get IP address programatically ?

Joaquín M López Muñoz13-May-02 7:38

Joaquín M López Muñoz

13-May-02 7:38

Use <a href="http://msdn.microsoft.com/library/en-us/winsock/wsapiref_8woi.asp">getpeername</a>.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

CAsyncSocket / CSocket In a Different Thread

alpha+13-May-02 5:56

alpha+

13-May-02 5:56

I want my app to open a TCP communication thread to work with a certain device, which is not "dumb" in a way it can receive commands and even transmit some data back to my app in its own time. So I created a static thread function inside my control class for this reason only.

But, when I was trying to work with CSocket/CAsyncSocket *inside* the thread's context - MFC started to throw unhandeled execptions at me. so just to check things up - I moved the socket handling code into the main thread/process, and it worked fine there.

again - ALL the socket handling (including object declaration, creation, connect, ect) was done within the thread.

so what's the problem? anyone?

thanks for your help.

Re: CAsyncSocket / CSocket In a Different Thread

Joaquín M López Muñoz13-May-02 7:42

Joaquín M López Muñoz

13-May-02 7:42

Are you using a worker thread created with AfxBeginThread and a AFX_THREADPROC? If so, I think you got to use your CSockets inside a CWinThread-derived object --use the second form of AfxBeginThread.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: CAsyncSocket / CSocket In a Different Thread

Jon Hulatt13-May-02 22:48

Jon Hulatt

13-May-02 22:48

I suffered this problem a lot, and managed to sort it out.

My app has CSmtpListener in the main thread.

I created:- class CSmtpThread : public CWinThread
and gave it a member var of class CSmtpSocket : public CAsyncSocket

Then in CSmtpListener::OnAccept :-

void CSmtpListener::OnAccept(int nErrorCode) 
{
	// wait for the semaphore & decrement it
	WaitForSingleObject(m_hConnCountSemaphore, INFINITE);

	// accept the socket connection
	CAsyncSocket s;
	Accept(s);
		
	// create a new UI Thread, suspended
	CSmtpThread *p_SmtpThread = (CSmtpThread *)	
				AfxBeginThread(RUNTIME_CLASS(CSmtpThread),
				THREAD_PRIORITY_NORMAL,
				0,
				CREATE_SUSPENDED,
				NULL);

	// setup the new thread
	p_SmtpThread->Setup( s.Detach(), m_hConnCountSemaphore);

	// resume the thread's execution
	p_SmtpThread->ResumeThread();
}

The CSmtpThread::Setup function stores my semaphore handle and socket handle. Then, The CSmtpThread::InitInstance() attaches the handle to the member socket.

I used semaphores to control the number of child threads: it works quite nicely becuase the listener will sit and wait until the number of children drops before accepting the connection.

Jon

Signature space for rent. Apply Within.

Proerty page / wizard

13-May-02 4:55

Hello,
I have a "Wizard / Property page" type dialog app.. I am having problems pulling information from an edit box on page 1 from page 3.. Anyone have any ideas? It's probably something dumb..

Thanks,
Rob

Rob

Re: Proerty page / wizard

dlhson13-May-02 6:53

dlhson

13-May-02 6:53

See some code in this page (section Dialog&Windows)
http://www.codeproject.com/dialog/wizard2000.asp

Hung Son
A Vietnamese student
i-g.hypermart.net
dlhson2001@yahoo.com

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.