C / C++ / MFC

Re: Is this realy possible?

14-Jan-02 6:09

IS IT POSSIBLE

It is. The function to use is gethostbyname, which returns the IP address corresponding to a symbolic name. Of course, the success of this function depends on the resolution mechanism available (DNS most of the times).

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Rickard Andersson²⁰14-Jan-02 9:47

Rickard Andersson²⁰

14-Jan-02 9:47

But how will I do that with that function??
You said something

Joaquín M López Muñoz wrote:
Of course, the success of this function depends on the resolution mechanism available (DNS most of the times).

What do you mean... can you tell me in big steps how to go through this!?

YES YOU CAN!!

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©0d3 ©®4©k3® - That's me! Smile | :)

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Re: Is this realy possible?

Joaquín M López Muñoz14-Jan-02 11:03

14-Jan-02 11:03

OK... So if you're writting a client/server app, then you surely must be using Winsock under some form or another, aren't you? If you are not, then you have to initialize Winsock, as gethostbyname is a function within this library. See the Winsock Programmer's FAQ for details.
Now that you have WInsock properly initialized, all you have to do is call gethostbyname with the name of the server you want to resolve and extract the IP address from the return data. Something like this: (Warning: this has not even been compiled, typos expected)

CString strAddr; // where we'll store the IP
struct hostent *phe = gethostbyname(lpszServerName);
if(!phe||!phe->h_addr_list[0]){
  // gethotsbyname couldn't resolve the name
}
else{
  struct in_addr addr;
  memcpy(&addr,phe->h_addr_list[0],sizeof(addr));
  strAddr=inet_ntoa(addr);
}

Hope this helps.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

MFC hWnd pointers

Steve Severance14-Jan-02 3:37

Steve Severance

14-Jan-02 3:37

I am new to MFC and I have couple questions about how it handles its hWnds. I have a formview that is the only view in my app. A store a pointer to it in the FrameWnd class. Whenever I try to call controls on the form from other parts of the application it crashes. Why is this and what is the best way to access a form controls from other parts of the app?

Jon Hulatt14-Jan-02 5:34

Jon Hulatt

14-Jan-02 5:34

post your code! for where you store the pointer, and the bits where you try and access it and it crashes.

Its impossible for people to help you if you don't post your code. and remember to enclose it in html style <PRE> ... </PRE> tags!

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Steve Severance15-Jan-02 8:54

Steve Severance

15-Jan-02 8:54

Sorry.

I have a form that was created in the form editor. It has an edit control IDC_EDIT_LOG.

then I have

class MyClass
{
    void func();
};

func is

void MyClass::func()
{
CEdit *edit = (CEdit *)GetDlgItem(IDC_EDIT_LOG);
edit->SetWindowText(_T("Some Text"));
}

this code asserts and produces an access violation.

Any help would be much appreciated.

Steve

Jon Hulatt15-Jan-02 22:05

Jon Hulatt

15-Jan-02 22:05

If that asserts, look at the assert. If you hit "debug", then a comment in the MFC source code near the assert will normally give you more clues.

However, the most likely problem is that your CEdit *edit; is not a pointer to a created edit control. This could be for a couple of reasons....

1. is class MyClass a class representing your form (CDialog or CFormView), assigned to your dialog resource in classwizard??? If it's not, then GetDlgItem will be returned something wrong.

2. Are you sure that the edit control is created before myfunc gets called? what calls myfunc? if you're calling it in some of the form startup procedures, it would not be a good idea to use it before OnInitialUpdate().

If those pointers don't help, post your entire (proper) class definition.

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Message handling/command routing

Nish Nishant15-Jan-02 22:30

Nish Nishant

15-Jan-02 22:30

What is MyClass derived from?

Nish

Sonork ID 100.9786 voidmain
www.busterboy.org
If you don't find me on CP, I'll be at Bob's HungOut

Fredrik Skog14-Jan-02 3:08

14-Jan-02 3:08

E.g. I have a toolbar to which I can add buttons. Each button has a menu with two menu items: "Configure" and "Remove". The menu is displayed when the right mouse button is clicked on the button.
The menu is a child of the toolbar, thus having the message routing taken care of in the toolbar.

The question is, how can I tell which button the menu was invoked on, in order to know which button to remove when the user selects "Remove"? Is my design all wrong or what?
I am going (more) insane over this...

Cheers,

/Fredrik

Sonork ID: 100.11430:PhatBoy

Joaquín M López Muñoz14-Jan-02 3:18

14-Jan-02 3:18

I'm not 100% sure about this, but maybe GetFocus on the command handler will do...

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Joaquín M López Muñoz14-Jan-02 3:28

14-Jan-02 3:28

FOrget about my first reply (it won't work). Best way is to store on some well known variable a pointer to the button that last issued the popmenu.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Not Active14-Jan-02 4:15

Not Active

14-Jan-02 4:15

You can the id of the item selected by capturing the WM_MENUSELECT message.

Fredrik Skog14-Jan-02 21:17

14-Jan-02 21:17

The menu is already working fine. What I need to know is which button that invoked the menu. The button has a OnRButtonDown handler which displays the menu. When the user selects an item in the menu the command handling is taken care of in the parent toolbar. How do I make the toolbar aware of which button it was that issued the menu?

E.g.

CDynamicButton.cpp

void CDynamicButton::OnRButtonDown(UINT nFlags, CPoint point) 
{
	// Handle the menu (if any)
	if (m_hMenu)
	{
		HMENU	hSubMenu = NULL;
		CRect	rWnd;

		hSubMenu = ::GetSubMenu(m_hMenu, 0);
		GetWindowRect(rWnd);
		::TrackPopupMenuEx(hSubMenu, TPM_LEFTALIGN | TPM_LEFTBUTTON, rWnd.left, rWnd.bottom, m_hParentWndMenu, NULL);
	} // if

	CButton::OnRButtonDown(nFlags, point);
}

CMacroToolBarCtrl.cpp:

BEGIN_MESSAGE_MAP(CMacroToolBarCtrl, CDialogBar)
	ON_UPDATE_COMMAND_UI(ID_MENU_REMOVE, OnMenuRemove)
END_MESSAGE_MAP()

void CMacroToolBarCtrl::OnMenuRemove(CCmdUI* pCmdUI)
{
	// Need to remove the button here
}

Cheers,

/Fredrik

Sonork ID: 100.11430:PhatBoy

Nish Nishant14-Jan-02 21:47

Nish Nishant

14-Jan-02 21:47

(1) Use GetItemRect to get the RECTs of all the buttons in your toolbar.

(2) In your OnRButtonDown you can get the CPoint of the area where the mouse was clicked

(3) Now figure out from these two, where the mouse was clicked

Regards
Nish

Sonork ID 100.9786 voidmain
www.busterboy.org
If you don't find me on CP, I'll be at Bob's HungOut

Fredrik Skog14-Jan-02 22:42

14-Jan-02 22:42

Well, that works for a CToolBar, but I am using a CDialogBar.
I think I have seen something somewhere about replacing original bitmap buttons in a CToolBar with all kinds of controls. Could this be an option?
(I want to use my own button class with only text on)

Cheers,

/Fredrik

Sonork ID: 100.11430:PhatBoy

Fredrik Skog15-Jan-02 1:37