Re: how to extract a piece of the CString? - C / C++ / MFC Discussion Boards

Re: how to extract a piece of the CString?

Daniel Lohmann25-Jul-02 22:50

Daniel Lohmann

25-Jul-02 22:50

Yeah, thats right Cool | :cool:

I tried hard for about three years to become comfortable with std::string, but then I gave up and since these day I use CString again. (I have extracted the CString sources from MFC, so I can use it even in non-MFC projects. However, these days you don't need to go this long way, because WTL includes also a CString implementation that can be used without MFC. And with the new VC7 template based CString class things got really nice.)

IMHO std::string is a bit overenegineered. To treat it as a general sequential container of characters of any type that has not to be null terminated is nice from the generic programming point of view (and I love generic programming and STL), but impractical.

I always missed things like GetBuffer() or Format() and other very string specific stuff. And I like that CString takes only 4 Bytes and you can even reinterperet this 4 Bytes as const char*. I like the automatic type conversion to LPCTSTR and that it does not crash if you assign it a NULL character pointer. And much more.

CString is the one and only thing of MFC that really rocks

--

Daniel Lohmann

http://www.losoft.de

Re: how to extract a piece of the CString?

Tomasz Sowinski25-Jul-02 23:36

Tomasz Sowinski

25-Jul-02 23:36

What about missing upper/lowercase conversions in std::string? And there's no real replace either.

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

- It's for protection
- Protection from what? Zee Germans?

Re: how to extract a piece of the CString?

Christian Graus26-Jul-02 1:58

Christian Graus

26-Jul-02 1:58

Tomasz Sowinski wrote:
What about missing upper/lowercase conversions in std::string?

That is one thing that std::string certainly lacks.

Tomasz Sowinski wrote:
And there's no real replace either.

A number of things are missing because it's assumed you'll use the algorithms the STL provides, which it plugs in to. But it is nicer having them all on the interface, one reason I tolerate CString, although I personally do not use MFC, and do not miss CString.

Christian

come on all you MS suckups, defend your sugar-daddy now. - Chris Losinger - 11/07/2002

Re: how to extract a piece of the CString?

Tomasz Sowinski26-Jul-02 2:06

Tomasz Sowinski

26-Jul-02 2:06

Christian Graus wrote:
A number of things are missing because it's assumed you'll use the algorithms the STL provides, which it plugs in to

Unfortunately, STL doesn't provide ready-to-use algorithm for string/string replacing in string, a'la CString::Replace(LPCTSTR, LPCTSTR). At least I don't know any - if you found one, let me know Smile | :)

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

- It's for protection
- Protection from what? Zee Germans?

Re: how to extract a piece of the CString?

Christian Graus26-Jul-02 2:10

Christian Graus

26-Jul-02 2:10

Actually, I think you are right - at work we have a class called CSTring, which mimics the MFC CString and is derived from std::string. I hate it, but I use it when I need Replace....

Christian

come on all you MS suckups, defend your sugar-daddy now. - Chris Losinger - 11/07/2002

Re: how to extract a piece of the CString?

Christian Graus26-Jul-02 1:57

Christian Graus

26-Jul-02 1:57

Daniel Lohmann wrote:
I tried hard for about three years to become comfortable with std::string,

Really ? I've only been coding three years. How hard did you try ?

Daniel Lohmann wrote:
I always missed things like GetBuffer()

It's called &string[0]. Smile | :)

Daniel Lohmann wrote:
or Format()

Format is ugly - an ostringstream does a much better job, and the framework is extensible.

Daniel Lohmann wrote:
And I like that CString takes only 4 Bytes and you can even reinterperet this 4 Bytes as const char*.

You can do this with c_str().

Daniel Lohmann wrote:
CString is the one and only thing of MFC that really rocks

It is adequate and there are things it does better, but it does not *cane* std::string, they are about on a par.

Christian

come on all you MS suckups, defend your sugar-daddy now. - Chris Losinger - 11/07/2002

Re: how to extract a piece of the CString?

Daniel Lohmann26-Jul-02 6:20

Daniel Lohmann

26-Jul-02 6:20

Christian Graus wrote:
Daniel Lohmann wrote:
I always missed things like GetBuffer()

It's called &string[0].

This does not help that much, because the standard does not ensure that the returned buffer is zero terminated Frown | :-(

Christian Graus wrote:
Daniel Lohmann wrote:
or Format()

Format is ugly - an ostringstream does a much better job, and the framework is extensible.

Oh yes - I tried this, too. But I found that most times I don't need the extensibility. Complex data types tend to do too much formatting for their output, so that it is only usable for debugging purposes but not for output to the end user. And those ostream concatenations tend to get really long and nearly unreadable:

printf( "Error %d (0x%x) in Module %s Line %d: %s.\n",
dwErrorCode, dwErrorCode, nLine, pszModule, pszMsg );

comes to

cout << "Error " << dwErrorCode << " (0x" << hex << dwErrorCode << ") in Module " << pszModule << "Line " << nLine << ": " << pszMsg << "." << endl;

I doubt that the above is really better to read, to write and especially to maintain.

Christian Graus wrote:
Daniel Lohmann wrote:
And I like that CString takes only 4 Bytes and you can even reinterperet this 4 Bytes as const char*.

You can do this with c_str().

No, you cant. I was not talking about conversion to LPCTSTR. The thing is that the memory layout of a CString instance is the same as for a char*. Thus one could write the following:

CString Text( "Hello World" );
TRACE("%s", Text );

Of course that is bad style, I only want to demonstrate the principle. The point is that it makes a lot of debugging tasks easier if you know that the 4 bytes representing a string point directly to the string buffer it manages - especially if you have to debug release builds...

--

Daniel Lohmann

http://www.losoft.de

Re: how to extract a piece of the CString?

Christian Graus26-Jul-02 13:42

Christian Graus

26-Jul-02 13:42

Daniel Lohmann wrote:
the standard does not ensure that the returned buffer is zero terminated

YEs, I've actually noticed that it isn't when using the memory window. But if you want zero terminated, then you're reading, not writing. In that case, c_str() is fine.

Daniel Lohmann wrote:
And those ostream concatenations tend to get really long and nearly unreadable:

printf( "Error %d (0x%x) in Module %s Line %d: %s.\n",
dwErrorCode, dwErrorCode, nLine, pszModule, pszMsg );

comes to

cout << "Error " << dwErrorCode << " (0x" << hex << dwErrorCode << ") in Module " << pszModule << "Line " << nLine << ": " << pszMsg << "." << endl;

I doubt that the above is really better to read, to write and especially to maintain.

You're kidding, right ? How is (0x%x) easy to ready, and not error prone ?

Christian

come on all you MS suckups, defend your sugar-daddy now. - Chris Losinger - 11/07/2002

Re: how to extract a piece of the CString?

Daniel Lohmann27-Jul-02 6:46

Daniel Lohmann

27-Jul-02 6:46

Christian Graus wrote:
YEs, I've actually noticed that it isn't when using the memory window. But if you want zero terminated, then you're reading, not writing. In that case, c_str() is fine.

I frequently need to read and write the same buffer. (I use a library that does a lot of in-place modifications of string buffers.)

Christian Graus wrote:
You're kidding, right ? How is (0x%x) easy to ready, and not error prone ?

I find it easy to read Big Grin | :-D

Of course, one has to know the printf format types and flags, but if you know them it is a very compact representation of what you intend to do...

Sometimes I got the feeling I am a bit old-fashioned. Blush | :O

(Actually the truth is, that I have learned C++ IO before I learned how to do it in C. Believe it or not: I was used to use ostream for quite a long time and then I moved to printf Roll eyes | :rolleyes:

)

--

Daniel Lohmann

http://www.losoft.de

Re: how to extract a piece of the CString?

Ravi Bhavnani25-Jul-02 17:11

Ravi Bhavnani

25-Jul-02 17:11

Check out _splitpath().

CString strPath = "C\\I386\\IAS.MDB";
char* pFullPath = strPath.GetBuffer (0);
_splitpath (pFullPath, ...);
strPath.ReleaseBuffer();

I'm working on releasing my FileSystem class to CP, which will make stuff like this easy to do.

Btw, have you become "nss" now? Smile | :)

/ravi

Let's put "civil" back into "civilization"
http://www.ravib.com
ravib@ravib.com

Re: how to extract a piece of the CString?

nss25-Jul-02 17:31

nss

25-Jul-02 17:31

Nope nss because its my home account. I wanted email to come here while I'm here, and you have to have another identity it appears for a different email(my experimentation). Thanks for that very interesting bit of code. Guess you're back now that the place has been cleaned up by the housekeeper ....

Re: how to extract a piece of the CString?

Ravi Bhavnani25-Jul-02 17:37

Ravi Bhavnani

25-Jul-02 17:37

She spends 2-3 hours at my place (I'm a neat freak Smile | :)

so it's easy to clean), but I spent most of the day at the bookstore and in search of food. Gonna lull myself to sleep with Petzold's C# tome.

I really should start posting articles again. I have a bunch of GUI helper code that would make the list control gymnastics you alluded to easy to do. Plus stuff for getting and validating edit controls, easily setting bunches of radio buttons, etc, etc. Stuff I got tired of duplicating in each project.

I'm going to crash now because I'm soooo sleepy. G'night!

/ravi

Let's put "civil" back into "civilization"
http://www.ravib.com
ravib@ravib.com

Re: how to extract a piece of the CString?

Stuart Dootson25-Jul-02 20:45

Stuart Dootson

25-Jul-02 20:45

...or alternatively you could use the Path functions in SHLWAPI. While _splitpath does this job, the Path ones will do some more difficult and tricky ones.

Stuart Dootson

'Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p'

Re: how to extract a piece of the CString?

Michael Dunn26-Jul-02 3:39

Michael Dunn

26-Jul-02 3:39

Use the API PathFindFileName() in shlwapi.dll Smile | :)

--Mike--
Just released - RightClick-Encrypt v1.3 - Adds fast & easy file encryption to Explorer
My really out-of-date homepage
Sonork-100.19012 Acid_Helm

Re: how to extract a piece of the CString?

ns26-Jul-02 3:41

26-Jul-02 3:41

Thank you very much indeed!
ns

Referencing a dialog

Scott_Perham25-Jul-02 16:27

Scott_Perham

25-Jul-02 16:27

I have created a CConBttn Class with a CButton base class...

On the "OnKeyDown" event, im trying to add text in to a modal dialog.

Is this possible??

if so... HOW!!!

thanx in advance.

Scott

Re: Referencing a dialog

Christian Graus25-Jul-02 16:39

Christian Graus

25-Jul-02 16:39

If your dialog is modal, then your keydown event will not be caught if it is not within the dialog in question.

Christian

come on all you MS suckups, defend your sugar-daddy now. - Chris Losinger - 11/07/2002

Re: Referencing a dialog

Ravi Bhavnani25-Jul-02 17:14

Ravi Bhavnani

25-Jul-02 17:14

Ugh, that is soooo hard to read! Smile | :)

Your name sounds familiar. Are you related to Mark Perham, the guy who wrote that cool Explorer look-alike way back when?

(Sorry, I didn't end up answering your question).

/ravi

Let's put "civil" back into "civilization"
http://www.ravib.com
ravib@ravib.com

How do I switch views in an SDI?

JohnnyG25-Jul-02 15:32

JohnnyG

25-Jul-02 15:32

I've got an SDI app with a CFormView in the main frame when it initializes. That works fine. I'd like to be able to toggle on/off that view to an empty client view via a menu command.

The MSDN docs say you can only have one view at a time in SDI but doesn't give any examples on how to remove the current view, create a new one and do I need a new frame window to do it?

I've tried to switch to a simple text view....but, I'm still trying to learn this doc/view stuff.

		appPtr->pDocTemplate->RemoveDocument(GetActiveDocument());
		delete appPtr->pDocTemplate;

		// simple text output view
		appPtr->pDocTemplate = new CSingleDocTemplate(IDR_TEXTTYPE,
			RUNTIME_CLASS(CTest3Doc),
			RUNTIME_CLASS(CMainFrame),
			RUNTIME_CLASS(CTextView));
		
		appPtr->AddDocTemplate(appPtr->pDocTemplate);
//		appPtr->pDocTemplate->CreateNewFrame(GetActiveDocument(), this);

Re: How do I switch views in an SDI?

nss25-Jul-02 16:35

nss

25-Jul-02 16:35

Try this out:

http://support.microsoft.com/default.aspx?scid=KB;EN-US;q141334&
I typed in "switch views mfc" in google and found some hits.
ns

Re: How do I switch views in an SDI?

JohnnyG25-Jul-02 16:38

JohnnyG

25-Jul-02 16:38

Thanks. I found something here. D-OH-H-H-H!!!! I Should have checked first. Anyways, in case anyone else want to know:

http://www.codeproject.com/docview/replacingview.asp
http://www.codeproject.com/docview/switchingviews.asp

download file incorrect

wangweisp25-Jul-02 14:49

wangweisp

25-Jul-02 14:49

I Read the article http://www.codeproject.com/useritems/asyncwininet.asp;
and write the code like 'asyncdemo' which from msdn:
http://msdn.microsoft.com/downloads/samples/internet/default.asp?url=/downloads/samples/internet/networking/asyncdemo/default.asp

but I have a question Confused | :confused:

when I call InternetQueryDataAvailable() ,it return ERROR_IO_PENDING
then I will recieve a callback status :INTERNET_STATUS_REQUEST_COMPLETE
and the LPINTERNET_ASYNC_RESULT (lpvStatusInformation)->dwError!=0,
the download incorrect.
what's the matter??? Cry | :((

the 'asyncdemo' alse download file incorrect
who have the source code of asynchronous download

thanks very much

Start Bar Question

gekoscan25-Jul-02 14:21

gekoscan

25-Jul-02 14:21

I am interested in making a window similar to a start bar but creating it at the top of the desktop and having it so that when a window is maximized it won't cover over the window I have created (instead all windows) will think that the bottom of my window is the top of the screen.

I know this can be done but I don't even know what it is called. If anyone could even tell me what this is called or point me in the right direction it would be greatly appreciated.

Thanks Cry | :((

Re: Start Bar Question

-Dy26-Jul-02 0:20

-Dy

26-Jul-02 0:20

Check out the SHAppBarMessage API. I've been meaning to right my first CP article on this - I promise I will get round to it as soon as I have moved house (about a week to 10 days ish, if you can wait that long)

Dylan Kenneally
London, UK

Re: Start Bar Question

Dave Matrix26-Jul-02 2:02

Dave Matrix

26-Jul-02 2:02

After creation of ur window, use SetWindowPos(...) with HWND_TOPMOST property for the hWndInsertAfter parameter. This will ensure that your application maintains its topmost position even when it is deactivated, ie other applications are having focus.

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