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A macro is a horrible construct left over from C. It basically means that where-ever MFC puts DECLARE_DYNAMIC(class_name), the code given is expanded out 'in place' by the preprocessor, with class_name replaced by whatever was passed in. To see why this is bad, consider a macro that takes a variable, x, and uses it three times in the expanded function, and what would happen if ++i was passed in as the value....
But in answer to your question, it allows the macro to be defined over multiple lines.
Christian
The tragedy of cyberspace - that so much can travel so far, and yet mean so little.
"But there isn't a whole lot out there that pisses me off more than someone leaving my code looking like they leaned on the keyboard and prayed that it would compile.
- Jamie Hale, 17/4/2002
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It basically allows the statement from the previous line to continue to the next line. Mainly they are used in macros like Christian Graus has explained above. There are not very many other useful uses for this operator.
Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!
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Ok,... for those who want to know... this is SilverShalkin... Dont think it matters but "oh well" im feeling light headed with all the information i have bean recieving through studying C++ 6.0. The more i study the more i feel as if i do not know anything. Mostly, all i want to do is learn all "all" the basics for that if i want to learn how to program somthing like DirectX I can learn it quicker because of my previous.
My question is.. What is the learning Curve of programming VC++ 6.0, "and only the basics"?
Second question... What are the easiest ways, "through experience" to learn all the basics of programming? "your story"
Thanks all for your help, hope to see some replies!
~SilverShalkin
![Rose | [Rose]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/rose.gif)
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Anonymous wrote:
Ok,... for those who want to know... this is SilverShalkin...
Hiya 
Anonymous wrote:
studying C++ 6.0
Nitpick - VC 6.0 is the development environment for writing programs in C++, which has no version number, except maybe C++98 ( and VC is a long way from supporting it ).
Anonymous wrote:
What is the learning Curve of programming VC++ 6.0, "and only the basics"?
Depends on how you define the basics, and how fast you learn. IMO the 'basics' are (in order)
1/ standard C++, which would include std::stream, basic iostream and vector usage, creating classes that derive from one another and use get/set methods to protect their data members. It would not have to include use of namespaces, templates, or other 'advanced' features.
2/ Dialog based programming with MFC, including use of different controls and interaction using DDX as well as control variables
3/ Some understanding of GDI, enough to load an image from resources or a bmp file ( using LoadImage ), draw some lines on it and put it on the screen.
Intermediate would include understanding how Doc/View works, some more standard C++, including namespaces at least, if not templates and maybe some ATL as well, how to create a COM server and use it in MFC.
DirectX is a whole different API, and I'd suggest you should be at intermediate level before learning it, so that you can focus on learning DX, in the same way you should write console programs until you know as much C++ as I've mentioned, so you can focus on the specifics of MFC without worrying about how to write a class, etc. I'd recommend learning OpenGL before Dx because it's easier to set up and there are some brilliant tutorials on the web. nehe.gamedev.org I believe is the best one, but I might have the URL slightly wrong....
Anonymous wrote:
What are the easiest ways, "through experience" to learn all the basics of C++programming? "your story"
Set yourself projects. I'm learning a ton of C# because of the screen saver contest, and every time I've learned a lot it's been because I've been able to find an excuse to start a project on something I know next to nothing about. Finish every one you start, and try to learn as much as you can when doing it. Don't be scared to ask questions, but don't be scared to look for answers yourself first.
And most important, take it step by step, don't sit down and try to write Quake 4 as your first ever C++ program. I can't emphasise enough the need to learn standard C++ before diving into MFC, or even win32 programming (which is harder, but less abstracted).
Christian
The tragedy of cyberspace - that so much can travel so far, and yet mean so little.
"But there isn't a whole lot out there that pisses me off more than someone leaving my code looking like they leaned on the keyboard and prayed that it would compile.
- Jamie Hale, 17/4/2002
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Christian Graus wrote:
Hiya
hey, thanks for anwering my thread with such detail "and hi again"
As everyone can see, i logged on. "i was just lazy before "
At this moment, i can pretty much do every thing, game relative with text. I even can learn more off of examples then a while ago "which is what ive bean trying to do the entire time "
Ill go check out OpenGL and see what i can do. "Im just overwhelmed; after climbing the first Vary Large mountain of info... I noticed that it was really a hill compared to all the other things i should get to know  (The mass of peaks)"
What i really want to know "by memory" is all the little details of all of every thing: Like int, the amount of bits used up by them, how fast it is to declare them, how fast it is to change them or recall them, everything. and beable to do this down to the organization of a project so that it runs faster by organization, than different code, and code lines. I want to teach someone and be able to say... "If you move that line of code out of that for loop, your program wll run so n so faster"
I feel like ive put on a ring of flying and flew over all the info that i shouldof looked over allot more closly. Now im looking at a fairly large prgramming book "which im 400 pages exactly into" wondering if i should just start over.
That is why i wanted to know the learning curve.. when will i feal like i have a little bit of knowledge into somthing that i have spent every day after school to study till my bedtime?
Thanks agian for the responses...
Ill start some little projects... "I was on makeing a tetris game, then go to a block out game, pacman, and then mario bro's" But i think ill start slightly below all that, and make some text games, and try to bring some image's into it.
Thanks!
~SilverShalkin
~and still on opinion... what is your story on learning...
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SilverShalkin wrote:
Like int, the amount of bits used up by them, how fast it is to declare them, how fast it is to change them or recall them, everything.
The size of int is implimentation specific, but most of what you're after here is pretty useless. The time it takes your computer to initialise an int is NEVER going to be where you need to optimise your game.
SilverShalkin wrote:
If you move that line of code out of that for loop, your program wll run so n so faster"
The truth is that while I recognise that, for example, ++i is faster than i++, in the end, it's not a difference a human could notice in pretty much every case.
SilverShalkin wrote:
when will i feal like i have a little bit of knowledge into somthing that i have spent every day after school to study till my bedtime?
I've been going for years, and I'm still not there yet
SilverShalkin wrote:
Thanks agian for the responses...
Ill start some little projects... "I was on makeing a tetris game, then go to a block out game, pacman, and then mario bro's" But i think ill start slightly below all that, and make some text games, and try to bring some image's into it.
So long as you know all the stuff I mentioned, and for games, especially the std library stuff. You'll find the STL invaluable for game programming. I'd also suggest that you learn DirectDraw maybe, and do these 2D games in 2D ( maybe with DirectDraw ?). I'd suggest the jump to 3D programming will be the hardest learning curve of the lot for you.
Christian
The tragedy of cyberspace - that so much can travel so far, and yet mean so little.
"But there isn't a whole lot out there that pisses me off more than someone leaving my code looking like they leaned on the keyboard and prayed that it would compile.
- Jamie Hale, 17/4/2002
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Hi there,
I have to dig into the pleasent toppic of establishing connection between computer and some external device of the industrial automation area.
Problem: an adapter from 4-20mA to RS232 would be needed.
Do you know where to get them (or at least where to get info on them)?
Thanks for your kind help.
Bunburry
The well-bred contradict other people, the wise contradict themselves.
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RaGe, thankx for your reply.
Example:
a remote pressure sensor, which has an output current signal 4-20 mA (4mA refers to 0 pressure, 20 mA refers to maximum pressure, 10 barg).
I have have to display the pressure as a function of time.
4-20mA is a 2-wire cable which I cannot connect to the serial port, as a result of which I will need an adapter which would convert a 2-wire current output of pressure sensor to an understandable signal for the serial port.
I am interested in any kind of equipment which can directly be connected to the computer over serial port.
Thankx
Bunburry
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just wondering if anybody could help me with a little project I'm at.
Basically I'm trying to extract text [and info] from a pdf file. Anybody have any ideas? [in general C++, not MFC]
Can't seem to find any articals on this.
<centre>
Now taking suggestions for a new sig. please email me all suggestions.
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Have you looked here yet?
http://partners.adobe.com/asn/developer/acrosdk/docs.html
Cheers,
Tom Archer
Author, Inside C#
Please note that the opinions expressed in this correspondence do not necessarily reflect the views of the author.
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You might want to check out CLIBPDF from www.fastio.com.
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In my program I need to test if the Selected Item in a tree control is at the end of a root. I'm guessing that I can get the info out of an HTREEITEM but I dont konw how to get the info. How can I get it?
Thanks in advance.
-Raffi
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Hi Raffi,
Do you mean testing if an item is at the end of a branch ? In that case, you
could simply test to see if it has any child items with GetChildItem(hItemSelected),
which will return NULL if no children exist.
Alwin
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Thanks alot
-Raffi
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Dear all,
Anybody knows a fastest file read/write method?
It is because i am doing a program and need to read/write a same file many many times, using CFile to read/write is very very slow.
Any suggest method?
Andy
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There is also FILE structure for doing that but I don't know if it is faster than CFile.
Mazy
"The path you tread is narrow and the drop is shear and very high,
The ravens all are watching from a vantage point near by,
Apprehension creeping like a choo-train uo your spine,
Will the tightrope reach the end;will the final cuplet rhyme?"Cymbaline-Pink Floyd
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An alternative is to use memory-mapped files, for which
some examples can be found on the Microsoft knowledge base. There
also exists a sample called ProcessWalker.
The downside is that it only works on NT or higher (I believe).
Alwin
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Memory mapped files work for all Win32 operating systems.
Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!
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why don't you try this in pure c?
e.g.:
FILE *fp1;
char word[100];
char c;
fp1 = fopen("yourfile.txt", "r");
do
{
c = fscanf(fp1, "%s", word);
DoSomethingWith(word);
}while (c != EOF);
fclose(fp1);
Bunburry
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A memory mapped file will still be faster because you will be accessing the file directly in memory.
You will have a pointer that points directly to the buffer that contains the file.
Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!
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I believe the multi-media IO functions provide the fastest file read/write performance on windows. Check out the mmioOpen function and all of its associated functions.
In an app I developed a couple of years ago, my tests showed that mmio outperformed every other method. I don't have the stats for just how much, but it was enough to make a difference.
My 2 cents.
Matt Gullett
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Please some body explain me why is this coming
warning LNK4089: all references to "OLEAUT32.dll" discarded by /OPT:REF
LINK : warning LNK4089: all references to "SHELL32.dll" discarded by /OPT:REF
LINK : warning LNK4089: all references to "comdlg32.dll" discarded by /OPT:REF
LINK : warning LNK4089: all references to "ole32.dll" discarded by /OPT:REF
Thank
Gaurika.;P  
Gaurika Wijeratne , www.gaurika.com
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The linker discarded the dll:s, as it found them unneccisary (probably the functions were packaged into COMDATs). If you want to link them in regardless, use /OPT:NOREF instead - or use /VERBOSE to see what was removed.
/moliate
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How can I use /OPT:NOREF instead - or use /VERBOSE
I mean were to put it.
Thanks
Gaurika..
Gaurika Wijerante
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Project -> Settings -> [Settings for Win32 Release*] -> Link -> Add to project options (add /verbose here)
* I assume you are doing a release build here, as the default for a debug build is /OPT:NOREF
You should now get a lot of information from the linker what is done in each pass.
An introduction to some optimizations the linker does can be found at: http://www.iecc.com/linker/linker11.html
/moliate
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