Re: Difference between ATL and COM - ATL / WTL / STL Discussion Boards

nm_11431-Oct-04 7:08

31-Oct-04 7:08

When I run my WTL program I get a resource leak in atlframe.h line 1225:

	HWND CreateEx(HWND hWndParent = NULL, ATL::_U_RECT rect = NULL, DWORD dwStyle = 0, DWORD dwExStyle = 0, LPVOID lpCreateParam = NULL)
	{
		const int cchName = 256;
		TCHAR szWindowName[cchName];
		szWindowName[0] = 0;
#ifndef _WIN32_WCE
#if (_ATL_VER >= 0x0700)
		::LoadString(ATL::_AtlBaseModule.GetResourceInstance(), T::GetWndClassInfo().m_uCommonResourceID, szWindowName, cchName);
		HMENU hMenu = ::LoadMenu(ATL::_AtlBaseModule.GetResourceInstance(), MAKEINTRESOURCE(T::GetWndClassInfo().m_uCommonResourceID));
#else //!(_ATL_VER >= 0x0700)
		::LoadString(_Module.GetResourceInstance(), T::GetWndClassInfo().m_uCommonResourceID, szWindowName, cchName);
/*!LEAK HERE!*/	HMENU hMenu = ::LoadMenu(_Module.GetResourceInstance(), MAKEINTRESOURCE(T::GetWndClassInfo().m_uCommonResourceID));
#endif //!(_ATL_VER >= 0x0700)

I'm using WTL 7.5 and ATL 3.0. Is the leak because the two are incompatible? If so, how do I update ATL? I only found ATL 2.0 on the MS web site.

-thanks.

What is RPC

Ranjish29-Oct-04 3:14

Ranjish

29-Oct-04 3:14

What is RPC? How we implement that?

Re: What is RPC

Nicholas Cardi10-Nov-04 4:30

Nicholas Cardi

10-Nov-04 4:30

RPC = Remote Procedure Call.

How you implement it is up to you. You can use DCOM or CORBA a google search will give you tons of information on both of these RPC implementations

Forever Developing

Difference between ATL and COM

Ranjish29-Oct-04 1:20

Ranjish

29-Oct-04 1:20

Will anybody explain me the difference between COM and ATL

Re: Difference between ATL and COM

Kevin McFarlane29-Oct-04 2:00

Kevin McFarlane

29-Oct-04 2:00

ATL is merely a template class library designed to make COM development easier or at least quicker - does most of the boilerplate code for you.

Kevin

Re: Difference between ATL and COM

ThatsAlok29-Oct-04 20:41

ThatsAlok

29-Oct-04 20:41

Kevin McFarlane wrote:
ATL is merely a template class library designed to make COM development easier or at least quicker - does most of the boilerplate code for you.

Please Don't Mind,from whatever I know, Com is mere Specification and Win32api are Application program interfaces.

you can't treat Com and Win32 to MFc and ATL

Re: Difference between ATL and COM

Monty²29-Oct-04 2:05

Monty²

29-Oct-04 2:05

hmm...

The same difference that is between programming in Platform SDK and MFC

ATL is a set of classes used to make COM Programming *easier* (some purists might disagree and call ATL Spaghetti programming)

hope this sheds some light on the subject, get a good book or read some articles
Big Grin | :-D

C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg

Re: Difference between ATL and COM

User 2155971-Nov-04 19:07

User 215597

1-Nov-04 19:07

COM is a specification for creating binary reusable components.
To develop these components, You implement COM specification in a programming language like C,C++,JAVA,VB, etc
ATL is template library that helps you code/develop COM components faster. It uses Templates extensively.
I hope this helps

-------------------------
Have a great day ahead!
Regards,
Sohail Kadiwala
(My COM Blog - http://lovecom.blogspot.com)

modified 21-Apr-21 21:01pm.

Setting checked items in a CTreeViewCtrl

retro_coder28-Oct-04 23:24

retro_coder

28-Oct-04 23:24

Hi,

I have an instance of a CTreeViewCtrl. I initialise it like so:
CTreeViewCtrl tree = GetDlgItem(IDC_TREE1);

I have set show "Check Boxes" to true for my tree in the resource editor and they are displayed. However when I add an item and then set the check state like so:
HTREEITEM item = tree.InsertItem(name, TVI_ROOT, TVI_LAST);
tree.SetCheckState(item, TRUE);

The change isn't shown in the GUI. Is there something else I have to do?

I am using VC7 and WTL 7.5 build 4291.

Thanks in advance.

Re: Setting checked items in a CTreeViewCtrl

Jack Puppy16-Nov-04 1:24

Jack Puppy

16-Nov-04 1:24

This is a problem I remember having a while back, so I checked out some of my old code. I found this in one of my classes:

<br />
// FIX: "If you want to use this style, you must set the TVS_CHECKBOXES style<br />
// with SetWindowLong after you create the treeview control, and before<br />
// you populate the tree. Otherwise, the checkboxes might appear<br />
// unchecked, depending on timing issues.<br />
<br />
// Remove the checkboxes style on the tree control, then explicitly set it<br />
m_myTreeCtrl.ModifyStyle(TVS_CHECKBOXES,0);<br />
m_myTreeCtrl.ModifyStyle(0,TVS_CHECKBOXES);<br />
<br />
... later on in code ...<br />
<br />
m_myTreeCtrl.SetCheck(hTreeItem);<br />
<br />

Try using the ModifyStyle fix and see if it works for you.

Pssst. You see that little light on your monitor? That's actually a government installed spy camera. Smile and wave to big brother!

Re: Setting checked items in a CTreeViewCtrl

retro_coder16-Nov-04 17:55

retro_coder

16-Nov-04 17:55

That worked perfectly. Thanks a lot for that, it was giving me a real headache!

COM Out-Proc Exe Issue

DeepakSharma28-Oct-04 1:51

DeepakSharma

28-Oct-04 1:51

HI All,

My problem is related to the COM out-proc exe.
I have a COM server(EXE) which has 2 interfaces:-

ISingletonTest - This inteface acts like an entry point for the server.The component class is made singleteon by using the DECLARE_CLASSFACTORY_SINGLETON().This will be created only once.There is function getTest() in this interface which returns the pointer to second interface(ITest). Now as cllient only passes the uninitialized pointer of ITest , i make a call to CoCreateInstance() for intiliaizing the CTest component class.

The problem is when i call the function getTest(ITest *pVal) and i do some work and set this pointer to null it calls its destructor but it doesn't fress the main interface i.e ISingletonTest pointer.
As a result my out-proc exe never gets unloaded.

Ina nutshell could you explan why the module gets locked when i create a COM object in the process of my COM server.Is there any specific care to be taken care of while doing such programming.

Please provide your suggestions as soon as possible.I have strucked badly on this problem.

Thanks in advance.

Deepak

auto_ptr assignment and VC7 warning

Rob Caldecott28-Oct-04 1:45

Rob Caldecott

28-Oct-04 1:45

Having recently discovered the joys of STL, I have set about using it in my projects with gusto. I particularly like auto_ptr, but I have a newbie query. When I try and assign a new value to an auto_ptr, I am getting the following VC7 warning (I am using level 4):

warning C4239: nonstandard extension used : 'argument' : conversion from 'std::auto_ptr<_Ty>' to 'std::auto_ptr<_Ty> &'

For example:

std::auto_ptr<CMyClass> ap;
...
ap = std::auto_ptr<CMyClass>(new CMyClass); // Warning C4239

However, the following code doesn't generate the warning:

std::auto_ptr<CMyClass> ap;
...
std::auto_ptr<CMyClass> new_ap(new CMyClass);
ap = new_ap;

Any clues how I can avoid this warning? Note that CMyClass might look something like:

class CMyClass
{
public:
    ...
    CMyClass(void) { ... }
    CMyClass(const CMyClass& o) { ... }
};

The Rob Blog

Re: auto_ptr assignment and VC7 warning

Nemanja Trifunovic28-Oct-04 3:13

Nemanja Trifunovic

28-Oct-04 3:13

Welcome to the wonderful world of STL Smile | :)

As for std::auto_ptr, be sure to read this article[^] before using it - its copy semantic is "unusual" and it can cause problems. In fact, I prefer Boost smart pointers in my code - they are safer.

To try to answer your question, I believe you get the warning because the way assigment operator is declared in auto_ptr:

auto_ptr<_Ty>& operator=(auto_ptr<_Ty>& _Right) _THROW0()
	{	// assign compatible _Right (assume pointer)
	reset(_Right.release());
	return (*this);
	}

As you can see, it takes a reference as the argument, not a const reference.

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.

Re: auto_ptr assignment and VC7 warning

Rob Caldecott28-Oct-04 3:21

Rob Caldecott

28-Oct-04 3:21

I keep hearing about Boost - and I must admit, not being able to use auto_ptrs in STL containers is a real shame.

So now's your chance to sell me Boost - what else am I missing out on apart from a better auto_ptr?

Any suggested hacks for my auto_ptr assignment issue? Wink | ;)

The Rob Blog

Re: auto_ptr assignment and VC7 warning

Rob Caldecott28-Oct-04 3:59

Rob Caldecott

28-Oct-04 3:59

Just found a solution thanks to your link - 'reset' does the trick - reset(new CMyClass).

The Rob Blog

Re: auto_ptr assignment and VC7 warning

Nemanja Trifunovic28-Oct-04 5:48

Nemanja Trifunovic

28-Oct-04 5:48

Yep. That'll do.

As for the Boost smart pointers, be sure to read this article[^] (if you haven't already).

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.

Toolbar for Windows Explorer

iffi99227-Oct-04 23:25

iffi992

27-Oct-04 23:25

Hi All,

I have been trying to create a toolbar for Windows Explorer, I used the Wizard provided by Eric and the basic thing was there. I have got a button on the toolbar I need to know which file or files were selected int the explorer view when the button was clicked.

for more calrification it is just like the standard buttons of copy and paste, when we select some file and press copy it gets the name of the file, same is the thing I want to perform.

I have tried using IWebBrowser2 and the use the get_Document method of it but I dont know what I would be doing further Confused | :confused:

regards
Muhammad Aftab Alam.

vector<HANDLE> to CONST HANDLE *handles

Malcolm Smart27-Oct-04 2:12

Malcolm Smart

27-Oct-04 2:12

Hi
I have the following...

<br />
vector<HANDLE> handles;<br />
handles.push_back(CreateMutex(NULL , FALSE , "A"));<br />
handles.push_back(CreateMutex(NULL , FALSE , "B"));<br />
//snip<br />
<br />
WaitForMultipleObjects(handles.size() , (const HANDLE*)(&handles) , TRUE , INFINITE);<br />

Basically, the Wait doesn't. I replaced the vectors with an array of handles

<br />
HANDLE handles[2];<br />
handles[0]  = CreateMutex(NULL , FALSE , "A");<br />
handles[1]  = CreateMutex(NULL , FALSE , "B");<br />
//snip<br />
<br />
WaitForMultipleObjects(2 , handles , TRUE , INFINITE);<br />

and it works a treat. It's obviously me, I'm new to STL - I reckon it's the cast to the second param of WaitForMultipleObjects.

Thanks for any input...

Cheers

Angel¹⁰⁵⁸

*********************************************
The sooner you fall behind, the longer you have to catch up.

Re: vector<HANDLE> to CONST HANDLE *handles

Nemanja Trifunovic27-Oct-04 2:25

Nemanja Trifunovic

27-Oct-04 2:25

Try:

WaitForMultipleObjects(handles.size() , &handles[0], TRUE , INFINITE);

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.

Re: vector<HANDLE> to CONST HANDLE *handles

Malcolm Smart27-Oct-04 3:11

Malcolm Smart

27-Oct-04 3:11

Many thanks. Easy when you know how....and now I do.

Angel¹⁰⁵⁸

*********************************************
The sooner you fall behind, the longer you have to catch up.

WTL child window tabbing order

nemo26-Oct-04 5:03

nemo

26-Oct-04 5:03

I have been tasked to update a WTL program. The program creates many modeless windows, the windows are created with style pop-up and the parent for the window is set to NULL in the create call. The main problem is the tabbing order on the modeless windows is not working. I have verified the VK_TAB message arrives in the main dialog(pretranslate message function) that created the modeless dialogs. How do I go about forwarding the message to the appropriate dialog, or is there a simpler solution to make the tabbing work? I have never had to work with the tabbing msgs before and it all seems a bit mysterious what is really going on.

TIA

Re: WTL child window tabbing order

Igor Vigdorchik26-Oct-04 14:42

Igor Vigdorchik

26-Oct-04 14:42

Try something like this:

virtual BOOL PreTranslateMessage(MSG* pMsg)
{
    // If it's a 'Tab' key then the child dialog should handle it
    if (pMsg->message == WM_KEYDOWN && pMsg->wParam == VK_TAB)
        return m_dlgChild.PreTranslateMessage(pMsg);
}

Then in your child dialog message handler you handle it.
Igor.

Re: WTL child window tabbing order

Michael Dunn27-Oct-04 7:07

Michael Dunn

27-Oct-04 7:07

Each modeless window (I assume they're all dialogs?) should derive from CMessageFilter and override the PreTranslateMessage() method. The PreTranslateMessage() would do:

BOOL CYourWindow::PreTranslateMessage ( MSG* pMsg )
{
  return IsDialogMessage ( pMsg );
}

In each window's OnInitDialog(), register for pre-translate calls with:

CMessageLoop* pLoop = _Module.GetMessageLoop();
 
  ATLASSERT(pLoop != NULL);
  pLoop->AddMessageFilter ( this );

Look at the wizard-generated CMainFrame::OnCreate() if this part is still unclear.

--
I'm Michael Dunn and I approve this post.

Vote Trogdor in oh-four!

Re: WTL child window tabbing order

Pharago22-Apr-05 1:45

Pharago

22-Apr-05 1:45

use accelerators

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