why void CView::PostNcDestroy() is called? - C / C++ / MFC Discussion Boards

Re: beginner question... recursive function

Joe Woodbury15-Jul-13 10:43

15-Jul-13 10:43

The point is that values are returned in the eax register. The mathematical operation happens to end up with the result in eax AND eax isn't changed by any other operation. Thus it returns the right value. Problem is that something like an inline optimization could change that.

Re: beginner question... recursive function

Member 1008957916-Jul-13 6:33

Member 10089579

16-Jul-13 6:33

Thanks to all! Smile | :)

I understood!

Re: beginner question... recursive function

Erudite_Eric15-Jul-13 2:35

Erudite_Eric

15-Jul-13 2:35

Without the 'else' the program flow just goes to the end of the func and returns. However there is no return value, so anything calling fatt() and expecting a return value if the 'else' path is hit is going to be dissapointed.

modified 15-Jul-13 9:01am.

Re: beginner question... recursive function

Stefan_Lang15-Jul-13 22:24

Stefan_Lang

15-Jul-13 22:24

For me, both in Debug and Release mode, the compiler (VS 2010) issues a warning for the second version, indicating the problem.

I have set Warning level to 3, and I've found that the majority of Warnings at that level indicate true errors.

My advice to beginners is:
1. Set Warning level to at least 3 (but see link below)
2. Make sure you first understand the true meaning of each Warning and what kind(s) of problem(s) it could cause at runtime. Then fix it.*

Here's an interesting article on how to deal with warnings, including those that are off by default[^].

Relocated HDD sectors

RomTibi13-Jul-13 8:20

RomTibi

13-Jul-13 8:20

I'm intending to make a program that erase an HDD. I know that modern HDDs relocate potentially deffective sectors by SMART testing, and replace with other not normally accessible. Is there a way to access ALL the sectors?

VII. 36. When you surround an army, leave an outlet free. Do not press a desperate foe too hard.
SUN-TZU - Art of War

Re: Relocated HDD sectors

AlphaDeltaTheta13-Jul-13 20:34

AlphaDeltaTheta

13-Jul-13 20:34

Relocation (remapping) is done transparently by the disk firmware. When a sector is detected as bad, all it's data are transferred to a special reserve area called sparse area and all further read/write attempts are redirected to it. See this wikipedia article.[^]

Sparse areas are not accessible using any standard disk access methods as all LBA addressing to it automatically redirected. (But, it is possible that there may be some vendor-specific commands to do that)

*TIP: You can use ATA Secure Erase[^] command to perform a firmware level erase of disk sectors. The GNU Shred utility is a noteworthy program using this command.

Beauty cannot be defined by abscissas and ordinates; neither are circles and ellipses created by their geometrical formulas.

~ Carl von Clausewitz ~

Source

Re: Relocated HDD sectors

RomTibi14-Jul-13 6:37

RomTibi

14-Jul-13 6:37

Thanks a lot. Been a SunTzu fan I also like Clausewitz very much!

VII. 36. When you surround an army, leave an outlet free. Do not press a desperate foe too hard.
SUN-TZU - Art of War

why void CView::PostNcDestroy() is called?

yu-jian12-Jul-13 22:04

yu-jian

12-Jul-13 22:04

In a project, I use the CMainFrame* pMainFrame = new CMainFrame() to create a main frame.
When the function CMainFrame::OnNcDestroy is called, void CView::PostNcDestroy()
will be called. I donot know why CView::PostNcDestroy() will be called, in the function CFrameWnd::OnCreateClient()
no new CView is created. Is there anyone know why? Thanks. Frown | :(

Re: why void CView::PostNcDestroy() is called?

pasztorpisti13-Jul-13 5:27

pasztorpisti

13-Jul-13 5:27

Use your debugger. As a first step I would put a breakpoint into CView::PostNcDestroy() and check out the callstack. There you will see who calls it and if you are lucky you can track back the reason. As a second try I would keep track of the creation of every CView and then find out which one is getting deleted.

Re: why void CView::PostNcDestroy() is called?

Erudite_Eric15-Jul-13 3:08

Erudite_Eric

15-Jul-13 3:08

Have you got an edit, scroll, list objects in your window?

http://msdn.microsoft.com/en-us/library/ws8s10w4(v=vs.80).aspx[^]

[SOLVED]Exec under windows

AlphaDeltaTheta12-Jul-13 21:01

AlphaDeltaTheta

12-Jul-13 21:01

Thinking about the fork-exec model used common in Unixes. Windows doesn't have a fork() but has all exec() counterparts. So, how does windows behave in this case? Is it similar to unix (shared ds, open fd's etc.) or in a different way?

Ans: Exec is complete alien in windows. It spawns a new process.
Tried googling but answers came mostly about unixes

Beauty cannot be defined by abscissas and ordinates; neither are circles and ellipses created by their geometrical formulas.

~ Carl von Clausewitz ~

Source

Re: Exec under windows

Richard MacCutchan12-Jul-13 22:09

Richard MacCutchan

12-Jul-13 22:09

In windows you create processes and/or threads[^].

Use the best guess

Re: Exec under windows

AlphaDeltaTheta12-Jul-13 23:08

AlphaDeltaTheta

12-Jul-13 23:08

Richard MacCutchan wrote:
In windows you create processes and/or threads[^].

I'm afraid, that's not what I asked. Being a windows developer I'm aware of the model used in windows.

Ok, then let me put my case here: I have a small unix app (written many many days ago) and now, I want to run it on windows. It has a certain case when it executes another executable with an exec() family call. This replaces the entire process with the child process, including the PID. Is this possible with the exec() family under windows?

Beauty cannot be defined by abscissas and ordinates; neither are circles and ellipses created by their geometrical formulas.

~ Carl von Clausewitz ~

Source

Re: Exec under windows

Richard MacCutchan12-Jul-13 23:18

Richard MacCutchan

12-Jul-13 23:18

See exec family in Windows[^].

Use the best guess

Re: Exec under windows

AlphaDeltaTheta12-Jul-13 23:22

AlphaDeltaTheta

12-Jul-13 23:22

Before posting this message I also went through that page, but couldn't make anything out of it, because of my .NET background. Frown | :(

Only thing that caught my eyes was this:

A program executed with one of the _exec functions is always loaded into memory as if the maximum allocation field in the program's .exe file header were set to the default value of 0xFFFFH.

Can you explain what it does? Creates a new, detached porcess or replaces it just like unix.

Beauty cannot be defined by abscissas and ordinates; neither are circles and ellipses created by their geometrical formulas.

~ Carl von Clausewitz ~

Source

Re: Exec under windows

Richard MacCutchan12-Jul-13 23:31

Richard MacCutchan

12-Jul-13 23:31

First sentence: Each function in this family loads and executes a new process.
You can use this either to launch an independent process that will run to completion with no interaction from the original, or you can connect to its stdin/out files for communication, or just wait for it to complete and check status. I think you can use the System.Diagnostics.Process[^] class in .NET in a similar manner.

Use the best guess

Re: Exec under windows

AlphaDeltaTheta13-Jul-13 16:03

AlphaDeltaTheta

13-Jul-13 16:03

Thank you.

Beauty cannot be defined by abscissas and ordinates; neither are circles and ellipses created by their geometrical formulas.

~ Carl von Clausewitz ~

Source

Re: Exec under windows

pasztorpisti13-Jul-13 8:55

pasztorpisti

13-Jul-13 8:55

Unix like fork is quite foreign in windows. Cygwin simulates fork on windows: http://stackoverflow.com/questions/985281/what-is-the-closest-thing-windows-has-to-fork[^]
There are many "unix simulation libraries" available on windows (including cygwin, interix, ...) but I wouldn't recommend building on top of these if you don't have to. My opinion about the cygwin fork simulation: In the unix world many tools/scripts make use of spawining other processes and processing data by piping the output of one process to another process. Running the same script/program "network" on windows/cygwin is multiple times slower than running the same command on linux if it involves a lot of fork invocations (for example a simple ./configure and ./make combination is always much faster on linux).

Re: Exec under windows

jschell13-Jul-13 11:03

jschell

13-Jul-13 11:03

It is similar and different.

Loading two versions of Common Controls

Jonathan Davies12-Jul-13 1:35

Jonathan Davies

12-Jul-13 1:35

Using VS2008 Professional (v 9.02) in Debug mode on Windows 8 to write a Win32 program I have two versions of Windows Common Controls ComCtl32.dll loading. On a call to: CreateDialogParam one: Product Version 6.2.92.../File Version 5.82.92... loads then on a call to SetupDiGetClassImageList another one loads having Product Version 6.2.92.../File Version 6.10.92.

I only noticed when having problems trying to use a feature of ListView header (up/down sort arrows) that various Googled sources attribute to needing a later version of ComCtl32.dll.

I had a look at the Manifest but see nothing seems relevant there. Switching to Release mode had no effect.

Is it possible to just load one version, preferably the later version loading?

The above with slightly more detail from the VS Output window is below for reference if needed.

In Debug mode:
Between:

hSelectDlg = CreateDialogParam(hInst, MAKEINTRESOURCE(IDD_DIALOG_SELECT), 0, DialogProc, 0);

and entering

BOOL CALLBACK DialogProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)

Loaded 'C:\Windows\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_5.82.9200.16384_none_bf100cd445f4d954\comctl32.dll'

then on a call:

BOOL b = SetupDiGetClassImageList(&m_spImageData);

Loaded 'C:\Windows\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.9200.16579_none_8937eec6860750f5\comctl32.dll'

Re: Loading two versions of Common Controls

Randor 12-Jul-13 15:01

Randor

12-Jul-13 15:01

Hi,

Have you tried adding a /MANIFESTDEPENDENCY entry for common controls specifying version six and above? Follow the instructions here:

Enabling Visual Styles[^]

Best Wishes,
-David Delaune

Re: Loading two versions of Common Controls

Jonathan Davies12-Jul-13 23:33

Jonathan Davies

12-Jul-13 23:33

David,

No I hadn't tried anything in the manifest. I've had a quick scan of the link you set and (initially)took the quick option of pasting in the example #pragma just as it's given for a version version= '6.0.0.0' to set the version from a .h file. No obvious difference yet as its still loading a v5 and a v6.

Of relevancet, I have a WTL/ATL version that I can step through side by side with the Win32 version and the WTL/ATL only loads one ComCtl32.dll, the v6.

I'll have a look in more detail later.

Thanks

... controls_6595b64144ccf1df_5.82.9200.16384_none_bf100cd445f4d954\comctl32.dll
...
... controls_6595b64144ccf1df_6.0.9200.16579_none_8937eec6860750f5\comctl32.dll

Re: Loading two versions of Common Controls

Jonathan Davies13-Jul-13 9:05

Jonathan Davies

13-Jul-13 9:05

Adding manifest as recommended prevents v5 ComCtl32.dll loading, just the v6 but as soon as I open the my dialog with my ListView control on it's gone. Just flickers on the screen and disappears. Calling

C++

InitCtrls.dwICC = ICC_LISTVIEW_CLASSES;
BOOL bInit = InitCommonControlsEx(&InitCtrls);

or not doesn't affect it.Stripped out a most of the functionality but it still happens ...

Re: Loading two versions of Common Controls

Jonathan Davies14-Jul-13 5:25

Jonathan Davies

14-Jul-13 5:25

The dialog with listbox using one ComCtl32 6 and not loading a v5 at well that flicked out of existence didn't bode too well for debug success so I started from scratch putting in a manifest line at the beginning and it displays. Only one ComCtl32 6.0.9200.16579 is loaded so that looks like success (apart from having to cut'n past stuff stuff).

Thanks

CStringArray vs. CArray<CString>

hans.sch11-Jul-13 5:33

hans.sch

11-Jul-13 5:33

Hi,

I am wondering what might be the advantage of CStringArray over CArray<CString, LPCTSTR>. The background is that I am planning to implement a CStringArray-like template class which is either explicitly ANSI or explicitly Unicode, and would like to implement it as CArray<CStringA, LPCSTR> and CArray<CStringW, LPCWSTR>, respectively.

Thank you for any comments.

Hans

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