Ad:

C++ Discussion Thread
Marked Solved
Views: 879

Jul 2nd, 2009

Need some help understanding MFC

Expand Post »

I'm having some of trouble understanding exactly how an MFC GUI works.

What is the resource file for and exactly how does it relate to the classes you create (e.g. the subclass of CDialog)?

Specifically, I want to add some bitmap buttons (CBitmapButton) to my dialog, so I followed the first part of this article:
http://www.functionx.com/visualc/controls/bmpbtn.htm

Everything worked fine, but then later on it says to use the resource ID of your bitmap button. How would I go about creating a resource ID and adding it to the resource script?

I added some regular buttons to my dialog using the dialog editor, and found this in the script:

C++ Syntax (Toggle Plain Text)
BEGIN
    PUSHBUTTON      "Button1",IDC_BUTTON1,57,46,50,14
    PUSHBUTTON      "Button2",IDC_BUTTON2,129,47,50,14
    PUSHBUTTON      "Button3",IDC_BUTTON3,55,18,50,14
    PUSHBUTTON      "Button4",IDC_BUTTON4,121,19,50,14
END
BEGIN
    PUSHBUTTON      "Button1",IDC_BUTTON1,57,46,50,14
    PUSHBUTTON      "Button2",IDC_BUTTON2,129,47,50,14
    PUSHBUTTON      "Button3",IDC_BUTTON3,55,18,50,14
    PUSHBUTTON      "Button4",IDC_BUTTON4,121,19,50,14
END

If I wanted to access the actual object of one of those buttons and call it's functions, how would I do that? Also, is there anything instead of "PUSHBUTTON" that I can use for CBitmapButtons?

I've taken a look at all the files VS generated but can't figure out how everything works together. None of the MFC tutorials I've looked at bother explaining the relationship with the resource script either.

Any help would be appreciated. Thank you.

Similar Threads

How do i do chat program using MFC (Microsoft Foundation Classes) and Visual Basic? in Visual Basic 4 / 5 / 6
Some help understanding #define with C in C
Quit abruptly in MFC app in C++
Need Help Understanding Subject in C++ in C++
Difficulty understanding Object Orientated File Streaming in C++

muhandis

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

8 posts
since Jun 2009

Permalink

Jul 2nd, 2009

Re: Need some help understanding MFC

what compiler and version are you using?

Microsoft has a Scribble Tutorial that's an introduction to MFC.

Last edited by Ancient Dragon; Jul 2nd, 2009 at 9:58 pm.

Ancient Dragon

Sponsor

Team Colleague

Featured Poster

Reputation Points: 5608

Solved Threads: 2282

Retired and Enjoying Life

Online

21,953 posts
since Aug 2005

Permalink

Jul 2nd, 2009

Re: Need some help understanding MFC

I'm using Visual Studio 2008.

Thank you for the link. I actually forgot the article uses provided source code, so I can look at exactly how they did it.

muhandis

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

8 posts
since Jun 2009

Permalink

Jul 3rd, 2009

Re: Need some help understanding MFC

muhandis>I'm having some of trouble understanding exactly how an MFC GUI works.

You should read MFC Fundamental - MSDN online page

adatapost

Moderator

Reputation Points: 2136

Solved Threads: 1228

Posting Genius

Offline

6,527 posts
since Oct 2008

Permalink

Jul 3rd, 2009

Re: Need some help understanding MFC

I understand a bit more after experimenting and looking at sample code. However, I'm still having a few problems and would really appreciate any help.

In this article: http://www.functionx.com/visualc/controls/bmpbtn.htm

It says to do declare the CBitmapButtons as members of the dialog in the second part, but doesn't explain how you're supposed to map the resource IDs to them. They just declare the controls and then the IDs pop out of nowhere when they have to provide them parameters.

Right now, I'm using this code (in OnInitDialog) to add a CBitmapButton to my dialog:

(Toggle Plain Text)

	CBitmapButton *btnMap = new CBitmapButton();
	btnMap->Create(NULL, WS_CHILD | WS_VISIBLE | BS_OWNERDRAW,
		CRect(0, 0, 0, 0), this, IDC_TESTBUTTON);
	btnMap->LoadBitmaps(IDB_TEST, 0, 0, 0);
	btnMap->SizeToContent();
	btnMap->SubclassDlgItem(IDC_TESTBUTTON, this);

However, I got an assertion failed error once I added that last line. I broke on the error, and got this as the cause:

(Toggle Plain Text)

BOOL CWnd::Attach(HWND hWndNew)
{
	ASSERT(m_hWnd == NULL);     // only attach once, detach on destroy
	ASSERT(FromHandlePermanent(hWndNew) == NULL);
		// must not already be in permanent map
...(Microsoft code)
}

Which is in wincore.cpp (line 329).

Also, according to the people who answered someone with a very similar problem here:
http://social.msdn.microsoft.com/For...0-0abd909d3e4e

You're supposed to just declare the buttons as members of the class (the normal way). Again, what I don't understand about that is how I am supposed to map the resource ID to the button.

Thanks

Last edited by muhandis; Jul 3rd, 2009 at 1:37 am.

muhandis

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

8 posts
since Jun 2009

Permalink

Jul 3rd, 2009

Re: Need some help understanding MFC

Click to Expand / Collapse Quote originally posted by muhandis ...

I'm using Visual Studio 2008.

Thank you for the link. I actually forgot the article uses provided source code, so I can look at exactly how they did it.

http://msdn.microsoft.com/en-us/library/f35t8fts.aspx

jencas

Reputation Points: 395

Solved Threads: 71

Posting Whiz

Offline

362 posts
since Dec 2007

Permalink

Jul 3rd, 2009

Re: Need some help understanding MFC

Thank you for the reply but someone already suggested that.

Still looking for help on my last post.

muhandis

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

8 posts
since Jun 2009

Permalink

Jul 3rd, 2009

Re: Need some help understanding MFC

I resolved my problems by getting rid of SubclassDlgItem and following this: http://msdn.microsoft.com/en-us/visualc/bb931337.aspx

Thank you all for your replies.

Last edited by muhandis; Jul 3rd, 2009 at 6:33 am.

muhandis

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

8 posts
since Jun 2009

This thread is solved

Either the thread starter or a moderator has marked this thread as solved. You can most likely trust the responses and answers given. There is most likely no reason for any further responses to be posted here. If you have a related question, please start a new thread in this forum instead.

This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

Previous Thread in C++ Forum Timeline: How to make a non-blocking socket?

Next Thread in C++ Forum Timeline: Will this code generates a segmentation fault???

DaniWeb Message

Cancel Changes

User Name
Password