C / C++ / MFC Discussion Boards

Prem Kumar27-Jun-02 19:44

27-Jun-02 19:44

SA wrote:
return a COM Obj from ATL

Ok, first of all you cannot return any objects.
What you can do is return an interface pointer
preferably IDispatch and the vb client will
interact thru it.

Re: How to return a COM Obj from ATL

A.A.28-Jun-02 17:13

A.A.

28-Jun-02 17:13

If I understand what you are trying to say, why don't you just create the second object like you did the first, and just retrieve the IUknown pointer... That is to say treat it as you would treat other one as the first one.

Re: How to return a COM Obj from ATL

29-Jun-02 7:45

Well, as I had pointed out, I am new to this env. and need a little more elaborate answer.

I created an ATL COM Project.
I added a Simple COM Object.
I added a second simple COM Object.

Now I want to add a method to the first one which takes a few String Parameters and returns (an interface pointer to??) the second object.

Can I get some example for the IDL and the function itself, which creates and returns the second COM Object ?

Thanks in advance.

Re: How to return a COM Obj from ATL

A.A.29-Jun-02 14:02

A.A.

29-Jun-02 14:02

What I was recommending is just create the new Object the same way you created the first one but apparantly by reading your new message I understand what you want to do is something a little different.

First of all you can't just return new Object and just cast that to IMyInterface*(If you want the reasons let me know). So what you need to create the first object with Aggretable support. Then create the second simple object using createInstance in the first Object(you will be passing the IUnkonwn* of the first object). Add the COM_INTERFACE_ENTRY_AGGREGATE() macro in the COM map. Dont forget to decrement the reference count when you dont need the second object(remember its still considered a COM object). No need to mess with IDL.

Note: There is a Macro similar to the above that takes care of creation and destruction.

If something is still unclear or need help with a specific part of the code let me know.

writing a dll

Steve L.27-Jun-02 14:24

Steve L.

27-Jun-02 14:24

I need to write a DLL and my books don't have a good explanation of how to do so. Any tutorials on the basics?

-Raffi

Re: writing a dll

Navin27-Jun-02 15:47

Navin

27-Jun-02 15:47

There's a secion here on CodeProject that has DLLs, system stuff, etc. There is an article called the ultimate DLL Header file, which explains the ways of how to declare functions to be exported, etc.

Even if you win the rat race, you're still a rat.

Re: writing a dll

Alexandru Savescu27-Jun-02 18:06

Alexandru Savescu

27-Jun-02 18:06

Also, MSDN is a good place to start.

Best regards,
Alexandru Savescu

Set Check and CTreeCtrl

Mr. Bill27-Jun-02 13:34

Mr. Bill

27-Jun-02 13:34

I saw where someone was having this same problem and it referenced a post that didn't show up so I am sorry but I must ask it again.

When I load the CTreeCtrl programmatically the checks do not show up. I have done Invalidate and all that and the only way I can get them to show up is if I show the control then empty it and read in the information again (I am buildiing it based on a XML file. I can't see any reason why I am getting this behaviour and have worked on it for a couple of days with nothing but a headache. Thank you very much if you can figure this out. I hope it isn't a stupid rookie mistake.

Bill

Re: Set Check and CTreeCtrl

Mr. Bill28-Jun-02 6:37

Mr. Bill

28-Jun-02 6:37

I figured it out. If you create the treectrl with the style tvs_checkboxes you must modify its style to remove that style then add it back. Or just create it without that style then do a modify and add it.

Bill

Accelerator Keys for dynamic created Context Menus

27-Jun-02 11:24

Hi !

I'm creating context menu's for a view dynamically (by code and depending on some conditions).

Is there a way to dynamically connect Accelerator Keys to this context menu or do I have to write a mechanism catching the WM_KEYDOWN or a similar message to implement that ?

[I'm using VC++ 6 & MFC, but some WinAPI-Calls to make that possible would also help]

Regards, Marco

Re: Accelerator Keys for dynamic created Context Menus

Prem Kumar27-Jun-02 19:56

Prem Kumar

27-Jun-02 19:56

Hi,

I think you can create an Accelerator table and load
it dynamically. Have a look at the foll functions
- CreateAcceleratorTable
- CopyAcceleratorTable
- LoadAccelerators

Re: Accelerator Keys for dynamic created Context Menus

Bill S27-Jun-02 20:27

Bill S

27-Jun-02 20:27

Try overloading the document methods below as:

HACCEL CMyDoc::GetDefaultAccelerator()
{
if (m_hAccelTable == NULL)
LoadAccelTable(MAKEINTRESOURCE(IDR_EDIT));

return m_hAccelTable;
}

BOOL CMyDoc::LoadAccelTable(LPCTSTR lpszResourceName)
{
ASSERT(m_hAccelTable == NULL); // only do once
ASSERT(lpszResourceName != NULL);

HINSTANCE hInst = AfxFindResourceHandle(lpszResourceName, RT_ACCELERATOR);
m_hAccelTable = ::LoadAccelerators(hInst, lpszResourceName);
return (m_hAccelTable != NULL);
}

Also overload this in the Main Frame derived class:

HACCEL CMainFrame::GetDefaultAccelerator()
{
HACCEL hAccelTable = m_hAccelTable;

// Get the active MDI child window.
CMDIChildWnd *pChild = (CMDIChildWnd *) GetActiveFrame();

// or CMDIChildWnd *pChild = pFrame->MDIGetActive();

// Get the active view attached to the active MDI child
// window.
if (pChild)
{
CView* pView = (CView*) pChild->GetActiveView();

if (pView)
{
CDocument* pDoc = pView->GetDocument();
if (pDoc)
hAccelTable = pDoc->GetDefaultAccelerator();
}
}

return hAccelTable;
}

OLE DB Provider running as a service?

StefanM27-Jun-02 11:19

StefanM

27-Jun-02 11:19

I have created a ATL/COM project in VC6 that will run as a service. Then I added a OLE DB Provider and modified it to just return 2 rows of a very simple record layout.
It compiles with no errors or warnings!
Then I launch Visual Basic and create a standard exe projekt, the first thing I do is to add a DataEnvironment Designer. When I open the property dialog on "Connection1" I get a list of providers to choose from, and my provider is listed there.
When I select the provider I have created and presses next button, I get an error message saying something like this: "The provider is not available, check that you have installed it correctly" !!!!!!
Confused | :confused:

What have I missed? How do I install/register my provider?

Is it not possible to have OLE DB providers in an ATL/COM project running as a service?

I have ofcourse started the service!

Don't give me a RTFM, cause I have!

Confused

SystemTray tooltip text limit

Ola Carlsson27-Jun-02 11:04

Ola Carlsson

27-Jun-02 11:04

Hi,

How can I use SystemTray tooltip text up to 256 characters (or more)?
Today it seems to only support 64 characters.

Thanks
Ola Carlsson

Exe File

27-Jun-02 8:54

Is there a way to allow an application to permanetly delete itself(file) after exiting or after a period of time.

Re: Exe File

Bill Wilson27-Jun-02 9:37

Bill Wilson

27-Jun-02 9:37

One way is to create a .bat file that deletes the .exe file and then itself. .bat files are loaded into memory and closed before execution, so a .bat can delete itself, where a .exe cannot.

You may have to do something to make the .bat wait until the app has been unloaded.

Re: Exe File

udayGovekar27-Jun-02 10:30

udayGovekar

27-Jun-02 10:30

Further on using .bat file,

This .bat file can be called from ur application.Execute this .bat file in applications destructor/exit function.

Other method,
Try to use close function .I am not very sure on this

Re: Exe File

Mazdak27-Jun-02 10:20

Mazdak

27-Jun-02 10:20

Check this Thread:

http://www.codeproject.com/script/comments/forums.asp?forumid=1647&app=50&tid=153951&select=153964#xx153951xx

Mazy

"If I go crazy then will you still
Call me Superman
If I’m alive and well, will you be
There holding my hand
I’ll keep you by my side with
My superhuman might
Kryptonite"Kryptonite-3 Doors Down

Re: Exe File

27-Jun-02 10:22

you can have it deleted on system restart by using the MoveFileEx() function, with the MOVEFILE_DELAY_UNTIL_REBOOT flag set and the destination parameter NULL. See the docs.

Re: Exe File

Navin27-Jun-02 12:33

Navin

27-Jun-02 12:33

Except that it doesn't work on 9X, only the NT variants.

Even if you win the rat race, you're still a rat.

Re: Exe File

[Shadow]27-Jun-02 14:31

[Shadow]

27-Jun-02 14:31

Good solution here:

http://www.microsoft.com/msj/defaultframe.asp?page=/msj/0198/win320198.htm&nav=/msj/0198/newnav.htm

sdi . problem

SilentWarrior27-Jun-02 8:43

SilentWarrior

27-Jun-02 8:43

hi im trying to hide some of my controls from the menu bar.. by typiing this code

void CMainFrame::OnModeEnrollmentOrdinary()
{

GetDlgItem(IDC_EDIT_FNAME)->ShowWindow(FALSE);

}
but it is not working.. and im getting a memory error sort of thing..
kindly tell me how to do it from a menu contol

looking forward from all the gurus of code

Re: sdi . problem

Alexandru Savescu27-Jun-02 10:46

Alexandru Savescu

27-Jun-02 10:46

Menu Items are not windows. You must either update the menu on the OnUpdateCommand handler or load a different menu from the application resource.

Best regards,
Alexandru Savescu

Re: sdi . problem

Prem Kumar27-Jun-02 19:50

Prem Kumar

27-Jun-02 19:50

Hi,

The edit box and other controls are not the direct children
of the Main Frame, so GetDlgItem will not work.

They are the children of the Dialog bar you have attached
to the MainFrame, for ex generally the dialog bar is named
'm_wndReBar'.

For this use
m_wndReBar.GetDlgItem(IDC_EDIT_FNAME)->ShowWindow(FALSE) ;

and it will work.

printer bins

pnpfriend27-Jun-02 8:29

pnpfriend

27-Jun-02 8:29

Hi all,
I'm writing a function that will print the first page of the document from the tray1 and the rest from the tray2.
so i wrote codes as following. However i have runtime error at
GetDeviceCapabilities(...)
What did I do wrong? and How should I fixed it??

<br />
<br />
CPrintDialog dlg(FALSE);<br />
  CDC dcPrinter;<br />
  DOCINFO docinfo;<br />
  dlg.GetDefaults();<br />
  HDC hdcPrinter = dlg.GetPrinterDC();<br />
  HDC DefaultPrinter = hdcPrinter;<br />
  dcPrinter.Attach(hdcPrinter);<br />
  <br />
  if (theApp.my_DevMode != NULL) <br />
    ::GlobalFree(theApp.my_DevMode);<br />
  theApp.my_DevMode = dlg.m_pd.hDevMode;	<br />
  LPDEVMODE lp = (LPDEVMODE) ::GlobalLock(theApp.my_DevMode); <br />
  ASSERT(lp); <br />
<br />
LPCTSTR pDevice = (LPCTSTR)dlg.GetDeviceName();    // pointer to a printer-name string<br />
LPCTSTR pPort = (LPCTSTR)dlg.GetPortName();      // pointer to a port-name string<br />
WORD fwCapability = DC_BINS;  // device capability to query<br />
LPTSTR pOutput;     // pointer to the output<br />
<br />
DeviceCapabilities(pDevice,pPort,fwCapability,pOutput,lp);  // program stop here. runtime error. runtime error<br />
<br />
if(pOutput!=NULL)<br />
{<br />
  CWordArray binsArray = (CWordArray)pOutput;  <br />
lp->dmDefaultSource = binsArray.GetAt(0);  // print from whatever tray in the binsarray zero.<br />
}<br />
<br />
  dcPrinter.ResetDC(lp);<br />
<br />

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