C / C++ / MFC Discussion Boards

Ben Burnett10-Jul-01 12:37

10-Jul-01 12:37

I think the simplest method would be to export a function that returns the DLL's resource handle -- see AfxGetResourceHandle(). Then when you’re loading your resources from that DLL, all you would need to do is call AfxSetResourceHandle() and pass it that DLL's handle...

HINSTANCE hInstOld = AfxGetResourceHandle ();<br />
ASSERT ( NULL != hInstOld );<br />
ASSERT ( NULL != hMyDLLResourceHandle );<br />
AfxSetResourceHandle ( hMyDLLResourceHandle );<br />
<br />
//<br />
// ... load the resource your looking for here<br />
//<br />
<br />
AfxSetResourceHandle ( hInstOld );

-Ben

---------
On the topic of code with no error handling -- It's not poor coding, it's "optimistic" Wink | ;)

Beginner Question: Updating Items in a list control

10-Jul-01 9:07

I try to change the value of a subitem of a item.

I do this :
-------------
int Index;
LVITEM ItemData;
CString strItem;
CString FileName;

Index = m_FindItemListCtrl(FileName);
ItemData.iItem = Index;
ItemData.mask = LVIF_TEXT | LVIF_STATE;
ItemData.iSubItem = 0;
ItemData.stateMask = 0xFFFF; // get all state flags

TransControlList.GetItem(&ItemData);

//Change subitem 3
strItem.Format(Progress);
ItemData.iSubItem = 3;
ItemData.pszText = (LPTSTR)(LPCTSTR)(strItem);
TransControlList.SetItem(&ItemData);
TransControlList.Update(Index);

This doesn't work! what's wrong?

Thanks a lot

Re: Beginner Question: Updating Items in a list control

Michael Dunn10-Jul-01 10:58

Michael Dunn

10-Jul-01 10:58

Use SetItemText() instead - much simpler. Smile | :)

--Mike--
http://home.inreach.com/mdunn/
Push the button, Frank.

Enumerating sibling windows in MFC

Patrick Hogan10-Jul-01 8:39

Patrick Hogan

10-Jul-01 8:39

I've implemented a SDI program which spawns a bunch of modeless child windows (dialogs) and I need a way for a dialog to enumerate all it's siblings in MFC. I tried the following code in my dialog code:

CWnd *wnd = GetWindow( GW_HWNDFIRST );
while ( wnd != NULL )
{
process( wnd );
wnd = wnd->GetWindow( GW_HWNDNEXT );
}

But it enumerates all kinds of unexpected things such as child buttons on itself as well as siblings. All I want are the sibling dialogs.

Any ideas?

Re: Enumerating sibling windows in MFC

Tomasz Sowinski10-Jul-01 9:32

Tomasz Sowinski

10-Jul-01 9:32

I don't believe you can get only siblings using GetWindow. The easiest way to solve your problem would be filtering the output GW_HWNDFIRST/GW_HWNDNEXT loop. If your dialogs have DECLARE_DYNAMIC/DYNCREATE/SERIAL, just test wnd->GetRuntimeClass()->m_lpszClassName.

Another solution: keep the list of open dialogs. Update the list in CYourDialog::OnInitDialog/DestroyWindow.

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

10-Jul-01 8:23

In my propertyPages I need to use member variable of their propertySheet object But it is unidentified .
How can I call this variable ???

I tried this: Hmmm | :|

-------------------------------------
CMyPropSheet* pSheet;
pSheet= (CMyPropSheet*)GetParent();
pSheet->myVariable.....
---------------------------------------

But in run-time when the program make the line :
pSheet= (CDefinitions*)GetParent();

it thrown out with the MessgeBox:
-------------------------------- Cry | :((

Debug Assertion Failed
File:afxwin2.inl
Line:265 Cry | :((

__________________________________

What can I doing ???

Excuse me on the missing title:" PropertySheet and PropertyPages," Please URGENT !!!

10-Jul-01 8:29

look on the prev question please.

Re: P

Carlos Antollini10-Jul-01 8:29

Carlos Antollini

10-Jul-01 8:29

In what event do you have the code?
Because I think that the problem is that the propertySheet is not initialized.

cheers!!! Smile | :)

Carlos Antollini.

Virtual message map functions?

Jake Palmer10-Jul-01 8:11

Jake Palmer

10-Jul-01 8:11

Is it possible for message map functions to be inherited? I'm trying to catch the ON_WM_ERASEBKGND message, and code the handler for all subclasses. I basically just put "virtual" in the message map:
virtual afx_msg BOOL OnEraseBkgnd(CDC* pDC);

But the subclasses aren't executing the code. Am I trying to do something that I was never meant to do? Roll eyes | :rolleyes:

thanks,
Jake

Re: Virtual message map functions?

Tomasz Sowinski10-Jul-01 8:19

Tomasz Sowinski

10-Jul-01 8:19

You can achieve the 'inheritance' using second param of BEGIN_MESSAGE_MAP macro...

BEGIN_MESSAGE_MAP(CSubclassedWnd, CBaseWnd)

... where CBaseWnd is a class where OnEraseBkgnd does its job. No need to make it virtual.

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

Avoid the availability of F8 when loading win2k?

Joan M10-Jul-01 6:27

Joan M

10-Jul-01 6:27

Hello,

I think this is not the best place to ask, but I have used it a long time with extremely good results, and I don't know where to search for an answer...

Does anybody know how to do it?

Thank you in advance...

ON_CONTROL_RANGE

10-Jul-01 6:08

Hi,

Is there any catch to using the ON_CONTROL_RANGE handler? The debug version of my executable works fine but the release bombs when I use it. And if I replace ON_CONTROL_RANGE with individual handlers for all controls, the release version works fine!

Any pointers will be appreciated!

Thanks!

Re: ON_CONTROL_RANGE

Tim Deveaux10-Jul-01 7:08

Tim Deveaux

10-Jul-01 7:08

Be very sure you have used the correct num of parameters and return type in your handler. Most of these macros exhibit this 'crash in release' prob if you get this wrong.

NT Service with a GUI

James Spibey10-Jul-01 5:54

James Spibey

10-Jul-01 5:54

Hi,

I have created a fantastic NT service which does some cool stuff. However, I need a method to Administer this fabulous app. Ideally I'd like to be able to popup a GUI in the service with a windows message or something.

Is it possible for a Service to have a GUI? I've looked into it a little and saw the article here about the NT Service with a shell tray icon, but I need a full dialog based GUI.

Possible?

Cheers

James

Re: NT Service with a GUI

10-Jul-01 6:28

this is straight forward. Invoke your dialog in the normal fashion with CDialog. (just like its done from the CApp implementation in a MFC framework based dialog appwizard project).

You're service needs to be able to "Interact with the desktop" though.

Re: NT Service with a GUI

Joan M10-Jul-01 6:33

Joan M

10-Jul-01 6:33

I have never done this, but the last 2 weeks I have been developing a service that loads a dll and installs a WH_KEYBOARD_LL hook in the system, and I have need some help and a lot of information.

There are a lot of good articles in the MSJ and in the MSDN about your question, but I'm sure about it's possible, the only thing you have to control is if the GUI is ready: if nobody has logged in and the desktop is not ready your gui will crash.

MSJ article:

Why Do Certain Win32 Technologies Misbehave in Windows NT Services?

There you will find info. about another article of Jeff Richter that clarifies more services.

Well, at last let me beg your pardon, my english it's very bad. (I'm novice with it...)

Re: NT Service with a GUI

Tim Deveaux10-Jul-01 7:21

Tim Deveaux

10-Jul-01 7:21

Messages are easy enough - just call MessageBox with the MB_SERVICE_NOTIFICATION flag set. No need to be logged in.

Administration really is best done by a separate desktop app communicating with the service - for example, you could set up a loopback TCP connection on an unused port with which to communicate from your admin dialog to the service.

If _monitoring_ the service is the primary goal, maybe UDP would be easier.

Re: NT Service with a GUI

Giles10-Jul-01 8:28

Giles

10-Jul-01 8:28

A good book on Services is Programming Server-Side Applications for Windows 2000.

It covers NT in general, and points out the pitfalls in advance, along with integration/administration/performance, scalability, security and stability issues which you should be aware of if writing services.

Its kind of a service bible.

Giles

Re: NT Service with a GUI

Gennady Oster10-Jul-01 21:47

Gennady Oster

10-Jul-01 21:47

Hi!
Possible decision - create the regular GUI application (may be - CPL), that stores the config info into the Registry, and in the service use RegNotifyChangeKeyValue to be informed, when the change occured, to be able to retrieve the new values.

Regards,
Gennady

Re: NT Service with a GUI

Claudius Mokler10-Jul-01 22:40

Claudius Mokler

10-Jul-01 22:40

A NT Service may well have a GUI, but this comes with some drawbacks.

Only services running in the "local system" user account can have the priviledge "interact with desktop", which is needed to have a visual GUI.

The "local system" user account is restricted in some access rights, for instance, it isn't allowed to open the client side of named pipes.

Another drawback is that every user who logs on to the machine the service runs on is abled to see and interact with the service's GUI.
This is not feasible for secure operation.

I would recommend using a separate GUI application for interaction with the service. Simple commands could be sent from GUI to service using user-defined codes for the ControlService() function.
Data could be sent using named pipes or shared memory (who'd want to do it that way?!) or sockets.

Re: NT Service with a GUI

Nick Van den Abbeele11-Jul-01 0:03

Nick Van den Abbeele

11-Jul-01 0:03

Why not creating a service with the ATL wizard and use the COM mechanism to interact between your service and your GUI application ? It's easier to use then named pipes or shared memory. After creating a service with the ATL wizard, you can adapt the CServiceModule::Run to do whatever you like (running code, adding COM objects, ...). There's a book about NT services that covers all of this (even how to optimize ATL created services for performance).

-Nick-

ListBox AddString Useage

otvac10-Jul-01 4:57

otvac

10-Jul-01 4:57

I am trying to populate a ListBox in a dialog.

My error is in this line:
m_MyDialog.m_ctlMyListBox.AddString("Hello");

I can populate the list box AFTER I open the dialog, but if I try to place anything in the ListBox BEFORE I open the dialog, I get a assertion error. I can, however, set other variables in the dialog prior to opening it.

Where have I failed?

Richard

Re: ListBox AddString Useage

Tomasz Sowinski10-Jul-01 5:06

Tomasz Sowinski

10-Jul-01 5:06

CListBox::AddString is just a thin MFC wrapper over Win32 message LB_ADDSTRING. The function will work only if your CListBox variable is properly initialized (mapped to some HWND). The initialization usually occurs in DoDataExchange called from CDialog::OnInitDialog - DDX_Control does this.

You can't initialize CListBox before dialog is created - there's no listbox window to be associated with C++ member variable of type CListBox.

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

Re: ListBox AddString Useage

10-Jul-01 6:32

Hello, the codegurus around the world. Smile | :)

If you have no idea of that ListBox is acutally created or not,
we can check this by GetSafeHwnd() or GetDlgItem();

if (m_MyDialog.m_ctlMyListBox.GetSafeHwnd())
or
if (m_MyDialog.GetDlgItem(IDC_MYLISTBOX))

These values isn't NULL,
we can add the string to the list box.

Otherwise, we must change the location which the code tries
to add the strings to the listbox. Cool | :cool:

Have a nice day.
-Masaaki Onishi-

Re: ListBox AddString Useage

Andrew Peace10-Jul-01 12:43

Andrew Peace

10-Jul-01 12:43

Populating a list box with it's initial contents is usually done in OnInitDialog(). You could always have a list of items in a collection which the OnInitDialog functions puts in the listbox at runtime if you needed to set your items up before the dialog is created.

> Andrew.

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