C / C++ / MFC

Re: Confusion regarding the "smartness" of smart pointers

4-Jun-02 17:29

CoInitialize(NULL);	
ISimplePgpPtr p(__uuidof(SimplePgp)); 	
p->EncryptFile("d:\\in.txt","d:\\a90.pgp","test@test.com");
p.Release();			
CoUninitialize();

Notice how I am calling Release()

My question is this. If it's a smart pointer shouldn't it automatically call Release() in its destructor?

Nish

p.s. I tried leaving out the call to Release() and it crashed Smile | :)

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Jim Crafton4-Jun-02 17:41

Jim Crafton

4-Jun-02 17:41

because you called CoUninitialize which happens before the smart pointer falls off the stack and has it's destructor called
try this:

CoInitialize(NULL);	
{
     ISimplePgpPtr p(__uuidof(SimplePgp)); 	
     p->EncryptFile("d:\\in.txt","d:\\a90.pgp","test@test.com");
     p.Release();			
}
CoUninitialize();

Re: Confusion regarding the "smartness" of smart pointers

Nish Nishant4-Jun-02 17:41

Re: Confusion regarding the "smartness" of smart pointers

4-Jun-02 17:41

Jim Crafton wrote:

CoInitialize(NULL);
{
ISimplePgpPtr p(__uuidof(SimplePgp));
p->EncryptFile("d:\\in.txt","d:\\a90.pgp","test@test.com");
p.Release();
}
CoUninitialize();

Thanks. That worked even when I commented out the call to Release()

Nish Smile | :)

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Ed Gadziemski5-Jun-02 14:45

Ed Gadziemski

5-Jun-02 14:45

Making it a statement block (enclosed in braces { }) forces the code to execute as a block and clean up after itself.

Smart Pointers - revisited

Nish Nishant4-Jun-02 17:16

Re: Smart Pointers - revisited

4-Jun-02 17:16

First of all, Thanks to Rama, Mazy and Jason.

Here is my code now. It works by the way Smile | :)

ISimplePgpPtr p(__uuidof(SimplePgp)); 	
p->EncryptFile("d:\\in.txt","d:\\a90.pgp","test@test.com");
p.Release();	
CoUninitialize();

Now this is my problem. I am puzzled by the behavior of p.

When I hit a . after p and when I type a -> after p I get different drop downs from intellisense.

Can someone clear all this up?

I tried a . instead of -> for the EncryptFile but got a compile error!

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Le centriste4-Jun-02 17:26

Le centriste

4-Jun-02 17:26

The . shows the member of _com_ptr_t class. this class has the -> operator overloaded, which shows you the member of ISimplePgp class.

Michel

It is a lovely language, but it takes a very long time to say anything in it, because we do not say anything in it, unless it is worth taking a very long time to say, and to listen to.

- TreeBeard

Re: Smart Pointers - revisited

Nish Nishant4-Jun-02 17:26

Re: Smart Pointers - revisited

4-Jun-02 17:26

Michel Prévost wrote:
The . shows the member of _com_ptr_t class. this class has the -> operator overloaded, which shows you the member of ISimplePgp class.

Thanks Michel. Makes sense now Smile | :)

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

nay4-Jun-02 18:23

nay

4-Jun-02 18:23

Michel is right it's just overloaded.

Extra info.

I finished a Design Patterns class last semester and the overloaded operator -> was given as an example. It's a Proxy design pattern. If you're interested here's a link.

Houston Design Patterns [same page]

It's in the Structural Patterns. Check out the C++ demo for Proxy design pattern. When you get to the source I believe it's the 3rd example.

nay

Help, please! How to getactiveview from MyApp

lucy4-Jun-02 16:49

lucy

4-Jun-02 16:49

Hello, CPians, I have an MFC SDI application, and I want to access to CMyView from CMyApp::InitInstance(), how can I get it?

Thanks a lot in advance! Rose | [Rose]

Nish Nishant4-Jun-02 17:18

4-Jun-02 17:18

lucy wrote:
I want to access to CMyView from CMyApp::InitInstance(),

Have you created your main frame window? If so you can call GetActiveView on the main frame pointer.

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

lucy4-Jun-02 17:26

lucy

4-Jun-02 17:26

yes, it should be created in the standard initialization code in CMyApp::InitInstance(). But what is the pointer to the main frame window? I tried to use m_pMainWnd, but it has no member function of GetActiveView.

Nish Nishant4-Jun-02 17:25

4-Jun-02 17:25

((CFrameWnd*)m_pMainWnd)->GetActiveView()

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

lucy4-Jun-02 17:39

lucy

4-Jun-02 17:39

Nish, you are so great! Thank you so much! Rose | [Rose]

Okay, now I can go to bed to have my beauty sleep. Smile | :)

TrackPopupMenu

Steve L.4-Jun-02 15:53

Steve L.

4-Jun-02 15:53

I have an icon in the system tray. When I right click the icon I do this:

pPopup->TrackPopupMenu(TPM_LEFTALIGN | TPM_LEFTBUTTON,
	point.x, point.y, AfxGetMainWnd(),NULL);

where pPopup is a pointer to my menu. When I right click it, if you dont want to do anything you would click outside of the popup menu and it dissappears, however it doesnt dissappeat unless you click the mouse outside of the menu then hover the mouse over the menu. How do I fix that?

-Raffi

Shog⁹4-Jun-02 16:11

Shog⁹

4-Jun-02 16:11

Try using TPM_RIGHTTBUTTON, or not using TPM_LEFTBUTTON.

--------

Life is fraught with opportunities to keep your mouth shut.

--Shog⁹ --

Steve L.4-Jun-02 16:09

Steve L.

4-Jun-02 16:09

I have, it has no affect.

-Raffi
Why do today what can be put of until tommorrow?

Shog⁹4-Jun-02 16:20

Shog⁹

4-Jun-02 16:20

Raffi wrote:
I have, it has no affect.

Odd...

I just checked MSDN, it gives this little tidbit:

To display a context menu for a notification icon, the current window must be the foreground window before the application calls TrackPopupMenu or TrackPopupMenuEx. Otherwise, the menu will not disappear when the user clicks outside of the menu or the window that created the menu (if it is visible). However, when the current window is the foreground window, the second time this menu is displayed, it displays and then immediately disappears. To correct this, you must force a task switch to the application that called TrackPopupMenu at some time in the near future. This is done by posting a benign message to the window or thread, as shown in the following code sample:

SetForegroundWindow(hDlg);

// Display the menu
TrackPopupMenu(   hSubMenu,
                  TPM_RIGHTBUTTON,
                  pt.x,
                  pt.y,
                  0,
                  hDlg,
                  NULL);

PostMessage(hDlg, WM_NULL, 0, 0);

Have you tried that?

--------

Life is fraught with opportunities to keep your mouth shut.

--Shog⁹ --

Steve L.4-Jun-02 16:17

Steve L.

4-Jun-02 16:17

Thats exactly the problem. Thanks for the fix. Smile | :)

-Raffi
Why do today what can be put of until tommorrow?

Michael Dunn4-Jun-02 16:17

Michael Dunn

4-Jun-02 16:17

That's a long-standing known bug with tray icon menus. See Q135788 for a fix.

--Mike--
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Nish Nishant4-Jun-02 17:22