C / C++ / MFC

Re: How do I create a CDialog object without showing it?

22-Nov-07 0:26

I have a MFC dll in which the main code resides in a class that inherits a CDialog. In order to start the main code, I do the following:

BOOL CdllEntryApp::InitInstance()
{
AfxEnableControlContainer();
m_pMainWnd = &theApp.myInstance;
theApp.myInstance.Create(IDD_MYDIALOG);
theApp.myInstance.ShowWindow(SW_HIDE);
return TRUE;
}

When I call the dll I can see the CDialog showing up and then very quickly disappear. This works, but it's not very pretty. What is the correct way to instantiate an object based on a CDialog without showing it?

CPallini22-Nov-07 0:42

Re: How do I create a CDialog object without showing it?

22-Nov-07 0:42

I think you should override PreCreateWindow method, removing WS_VISIBLE flag (e.g. cs.style &= ~WS_VISIBLE); however I didn't make a test.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

arnold_w22-Nov-07 1:37

Re: How do I create a CDialog object without showing it?

22-Nov-07 1:37

Thanks for your response. I added the following:

BOOL CdllMainCodeDlg::PreCreateWindow(CREATESTRUCT& cs)
{
cs.style &= ~WS_VISIBLE;
return CDialog::PreCreateWindow(cs);
}

and I added the following to the h-file:

protected:
virtual BOOL PreCreateWindow(CREATESTRUCT& cs);

However, the CdllMainCodeDlg::PreCreateWindow is never executed, why is that? Do I need to add something to BEGIN_MESSAGE_MAP(CdllMainCodeDlg, CDialog) also?

CPallini22-Nov-07 2:00

Re: How do I create a CDialog object without showing it?

22-Nov-07 2:00

Try to remove the WS_VISIBLE style in the dialog template inside resource (.rc) file.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Malli_S22-Nov-07 2:13

Malli_S

22-Nov-07 2:13

I don't think that would help. Because modal application dialogs can not be hidden. For that you've to go for modeless dialogs. I hope I'm right. Smile | :)

I also had faced the same problem, and even tried all these steps. Didn't help me that.

-Malli...!

Re: How do I create a CDialog object without showing it?

CPallini22-Nov-07 2:21

Re: How do I create a CDialog object without showing it?

22-Nov-07 2:21

Malli_S wrote:
For that you've to go for modeless dialogs

.
Of course. The above was implicit.
Big Grin | :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

arnold_w22-Nov-07 2:22

Re: How do I create a CDialog object without showing it?

22-Nov-07 2:22

Since I never call DoModal (I call Create instead) I think my dialog is not modal.

arnold_w22-Nov-07 2:16

Re: How do I create a CDialog object without showing it?

22-Nov-07 2:16

Thanks a lot, it works great now!

Malli_S22-Nov-07 2:09

Malli_S

22-Nov-07 2:09

Try this :
put a member pointer variable of your dialog class into the application class (e.g. m_pApplicationWnd). And add following code to InitInstance() of the application class.

m_pApplicationWnd = new CYourDlg();<br />
	m_pApplicationWnd->Create(IDD_DIALOG_ID);<br />
	m_pMainWnd = m_pApplicationWnd;<br />
	ShowWindow(m_pMainWnd->GetSafeHwnd(),SW_HIDE);<br />
	return TRUE;

Be sure to delete the allocated object in ExitInstance() of the application class.

<br />
	if(m_pApplicationWnd)<br />
	{<br />
		m_pApplicationWnd->DestroyWindow();<br />
		delete m_pApplicationWnd;<br />
	}<br />
<br />

This is to create modeless dialog, so that you can hide your application dialog !

-Malli...!

Re: How do I create a CDialog object without showing it?

arnold_w22-Nov-07 2:19

Re: Dynamic Port allocation

22-Nov-07 2:19

Thanks for your reply. CPallini's suggestion seems simpler and it seems to work just fine so I will use his suggestion instead.

Dynamic Port allocation

Shreyas Ganesh22-Nov-07 0:24

Shreyas Ganesh

22-Nov-07 0:24

Hi all,
I need to identify next available free port in a system and bind it to a socket.
I have done this on unix before but now have to do it on VC++ without MFCs. A tutorial directed me to do the following:

http://beej.us/guide/bgnet/output/html/singlepage/bgnet.html#windows

struct sockaddr_in my_socket_addr;
sockfd = socket(AF_INET,SOCK_STREAM,0);

my_socket_addr.sin_family = AF_INET; // host byte order
my_socket_addr.sin_addr.s_addr = htonl(INADDR_ANY); //automatically fill with server IP
my_socket_addr.sin_port = 0; // port wildcard
memset(my_socket_addr.sin_zero, '\0', sizeof my_socket_addr.sin_zero); // setting all to zero

if ( bind(sockfd, (struct sockaddr *)&my_socket_addr, sizeof(my_socket_addr)) < 0 )
{
cout<<" Error in Binding socket!!";
exit(1);
}

cout << "port = "<< ntohs(my_socket_addr.sin_port) << endl; // print port

Basically it says that by assigning sin_port=0 the bind function knows it must allocate dynamically.
But when i print the port number generated i get the portno assigned as 0. The allocation hasn't taken place.
Unsure | :~

What could be the reason?

I would appreciate if you could direct me to any other way of dynamically assigning port numbers in VC++.

Its quite urgent! need help please! Sigh | :sigh:

Thanks in advance

Shreyas

Moak29-Nov-07 23:50

Moak

29-Nov-07 23:50

Shreyas Ganesh wrote:
I have done this on unix before but now have to do it on VC++ without MFCs.

It is the same on Unix and Windows, you let the networking stack assign a free local port number. But there is an error in your code, you reset the structure after you assign it. Here is a fix:

<br />
	SOCKADDR_IN mySockAddr;<br />
	memset(&mySockAddr, 0, sizeof(mySockAddr));<br />
	mySockAddr.sin_family = AF_INET;<br />
	mySockAddr.sin_addr.s_addr = htonl(INADDR_ANY);<br />
	mySockAddr.sin_port = 0;<br />
        if(::bind(sockFd, (SOCKADDR*)&mySockAddr, sizeof(mySockAddr)) == SOCKET_ERROR) ...<br />

Hope that works for you.

Home page

TCHAR[500] to const char*

Paulraj G21-Nov-07 23:47

Paulraj G

21-Nov-07 23:47

TCHAR t;
const char *pc=cosnt char*(&t);

hi... i used this way.

but i didn't get the answer.

the error is "syntax error:'const'
what is wrong in above code?

my input is TCHAR[500];
i have to covert this in const char* format.
can anyone help me?

paulraj

Re: TCHAR[500] to const char*

CPallini22-Nov-07 0:11

Re: TCHAR[500] to const char*

22-Nov-07 0:11

TCHAR expands either to char (when _UNICODE is NOT defined) or to wchar_t (when _UNICODE IS defined) data type. Hence, if _UNICODE is not defined, you have already what you need. On the other hand, if _UNICODE is defined...uhm...dangers are beckoning on the horizon... Big Grin | :-D

Usually you should continue with generic text mapping (TCHAR) and avoid explicit assignment to standard data types.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

winter7723-Nov-07 19:32

winter77

23-Nov-07 19:32

Firstly, "const" on the right hand is not needed.

And then, why not try WideCharToMultiByte()?

On Timer

Chandrasekharan P21-Nov-07 23:40

Chandrasekharan P

21-Nov-07 23:40

i jus wanted to know how do i show the values in the edit box when i use the timer. this value should get updated every second. till a range. for example till 100. in the edit box it should display from 1 to 100. actually i am using a for loop to iterate te value till 100. but only the last value is printing. i have set the timer lik this

OnButton Function:
&

<br />
SetTimer(1,100,NULL);<br />
<br />

and on the OnTimer function:P

<br />
CString str1;<br />
	<br />
	<br />
	if (nIDEvent==1)<br />
	{<br />
	<br />
		for(int i=0;i<=100;i++)<br />
		{	<br />
			<br />
			str1.Format("%d",i);<br />
			if(i%2==0)<br />
			{<br />
				m_listbox.AddString(str1);<br />
				m_edit.SetWindowText(str1);<br />
			}<br />
		}<br />
			<br />
	}<br />

i know its a simple mistake. but i am not being able to figure out.

KarstenK22-Nov-07 0:35

KarstenK

22-Nov-07 0:35

Read what the SetTimer() does. It sets up a timer in ms. And in the handler you run to 100

Greetings from Germany

GauranG Shah22-Nov-07 1:58

GauranG Shah

22-Nov-07 1:58

might be the followig code work as u desire. Try it and let me know whether it worked or not. ( i know its in win32 and you are using MFC but i know u can make to use it )

#define ONE_SEC 1
int i=0;

case WM_INITDIALOG:
  SetTimer(hdlg,ONE_SEC,10*100,NULL);

  break;

case WM_TIMER:
 if (wParam == ONE_SEC)
   {
    SetDlgItemInt(hdlg,IDC_EDIT1,i++,FALSE);
    }
break;

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pierre_ribery22-Nov-07 11:14

pierre_ribery

22-Nov-07 11:14

You have not specified what is not working as expected, so please tell us what you want to do!

What do you need a timer for this?

Chandrasekharan P22-Nov-07 16:31

Chandrasekharan P

22-Nov-07 16:31

i dont know if there is another way other than timer to increment the value in a edit box every sec or millisecond. the problem is it only shows the last number that is 100. i have to show it from 1 to 100.

pierre_ribery22-Nov-07 19:43

pierre_ribery

22-Nov-07 19:43

ok, if I understand you correc, you want to increment the value of an edit box every 1 second, starting from 0 going to 100. If that is the case, then a timer is the way to go.

Your timer needs to be set up for 1000ms(1sec). You have set it up for 100ms only.

SetTimer(1,1000,NULL);

Now create a member variable for your edit control of type "value" and set its datatype to int. Lets call it "value".

In OnTimer:

if (nIDEvent==1)
{
if(value < 100)
{
value++;
UpdateData(FALSE);
}
}