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In 99.9999% cases you can avoid global variables. For example, you should declare it in CWinApp class or in MainFrame class. Both of them, have only one instance in the program, so you can access it by AfxGetApp()->theVariable or AfxGetMainWnd()->theVariable.
Robert-Antonio
It's a good luck, when you meet a real fink. Then you get a respect to
normal, mid-honest people."
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True, but you still have the global variable. All you are really doing is moving the global variable around so it isn't a traditional global variable. However, functionally, it still acts like a global variable and thus has most of the exact same problems associated with it.
I think it was Christian that said wrap the global variable in a global function. The good thing about this approach is that it makes it much easier to add some form of locking to the variable.
Tim Smith
I'm going to patent thought. I have yet to see any prior art.
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int count = 0;
void someFunc1()
{
count++;
}
extern int count;
void someFunc2()
{
count++;
}
By the way, does anyone know how to get codeproject to retain indentation?
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Hello, everyone,
In my project, I used CStaticLink class to change the static text to url style text. It works fine in different dialog boxes. But it is not working good in a CPropertyPage dialog box. The text is not changed to blue color and not underscored, but the link is still working good. I think the problem is from the second parameter *CWnd (in my code, I used "this"), but I cannot figure out what should it be.
What do I need to do to make it work?
Thanks a lot in advance.
Bin
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Hi all!
In my application I'm reading from a console and what is read is written in an edit box, but I need to append the new text so the prior text does not disappear. I normally write
<br />
m_strText=read_text;<br />
but this erases prior text in the Edit Box.
Any ideas?
Thank you in advance!
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very crude:
m_text = GetDlgItemText(IDC_MYEDITBOX);
m_text += new_console_text;
SetDlgItemText(IDC_MYEDITBOX,m_text);
"there is no spoon"
biz stuff about me
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I'm novice and would appreciate if I can get a sample/idea on how to accomplish this or sources where I can get oriented:
I need to define 4 classes, each containing its attributes and methods.
say, class a, b, c and d.
What do I have to do in my class declaration so that class d can
publicly overload class a and class b? (class inheritance?)
-How do I access the "private" instances (fields) in class a (a1 or a2) from class d?
-How do I access the member functions of class a in class d?
class a // Csamplea
{
private:
int a1;
int a2;
public:
a(int x, int y);
// default constructor
}
class b // Csampleb
{
private:
int b1;
int b2;
public:
b(int x, int y);
// default constructor
}
class c
{
private:
int c1;
int c2;
public:
c(int x, int y);
// default constructor
}
class d
{
private:
int d1;
int d2;
public:
d(int x, int y);
// default constructor
}
// class implementation
a::a(int x, int y)
{
a1 = x;
a2 = y;
}
// class implementation
b::b(int x, int y)
{
b1 = x;
b2 = y;
}
// class implementation
c::c(int x, int y)
{
c1 = x;
c2 = y;
}
// class implementation
d: (int x, int y)
{
d1 = x;
d2 = y;
// need to update a1, a2
}
Before hand, I want to thank you for any suggestions/ideas.
Thank you again,
Reni
Reni
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beamer_2020 wrote:
How do I access the "private" instances (fields) in class a (a1 or a2) from class d?
You can't, only protected variables and methods are visible to a derived class, that's why we have protected and private.
beamer_2020 wrote:
How do I access the member functions of class a in class d?
So long as they are not private, you can just call them, or use this-> if you want to be explicit about where they are coming from.
Christian
I have drunk the cool-aid and found it wan and bitter. - Chris Maunder
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Christian,
Thanks for the answer.
I will place the instances in "public".
Thanks again,
Reni
Reni
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If they were private, they should probably be protected. Don't make anything public unless it makes absolute sense to do so, private or protected should be your default.
Christian
I have drunk the cool-aid and found it wan and bitter. - Chris Maunder
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Christian,
Thanks again for your advice.
This is not for a project but for me to learn how sharing can be done within classes.
I also think I should be able to use Classes with Inheritance.
I will play with them. Thanks again.
Reni
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no worries. I guessed you were doing this to learn, which is why I'm trying to cover some best practice stuff, so you learn how to do things *well*. Good luck 
Christian
I have drunk the cool-aid and found it wan and bitter. - Chris Maunder
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Christian,
Thanks again.
I agree with you. Making the instances public in a class is kind of "ugly".
I will be testing inherited classes.
Thanks,
Reni
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beamer_2020 wrote:
What do I have to do
How do I
The best suggestion I can give you is that you read the introductory chapters of the C++ book assigned by the instructor. If you have specific questions, you'll find the CP community will be happy to help you. But don't expect a CP member to do your homework for you.
/ravi
My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com
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Ravi,
I wasn't expecting anyone to write code for me. I want to thank you for taking the time to reply.
Regards,
Reni
Renato
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Now I feel bad for my reply which appears harsher than I intended it to be. Sorry. ![Rose | [Rose]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/rose.gif)
/ravi
My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com
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Ravi,
Thanks again for your reply.
This is not for a school project. I'm just playing around with "classes" and wanted to experiment with sharing the instances (fields) between classes.
I replied to Christian and mentioned that I will probably try using "classes with inheritance". <class_specifier> <derived_class_name> : < base_class_name { additional members> };
Unfortunately some of the C++ books I have been reading, do not show you "interaction" between different classes at the beginning.
The other things I have seem is to make the instances public BUT it kinds of defects the beauty of C++.
Thanks again and please don't feel bad. I know of many people who want others to do everything for them.
Regards,
Reni
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Hey guys,
I'm having trouble reading an integer from a text file.
for example I have the following stored in a text file
------------ beginning of file------------excluding this line
H
88
------------ end of file------------excluding this line
and there are no spaces after any of the above words, each word is stored in one line.
I have an ifstream object that reads
char charVar;
int intVar;
inFile.read(reinterpret_cast<char*>(&charVar),sizeof(char));
cout <<"char value is : "<<charvar ;
infile.read(reinterpret_cast<char*="">(intVar),sizeof(int));
cout <<"int Var is : "<
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The number is stored in the file as text, so you have to read it in as text then transalte it into a number using atoi() ect.
Sonork 100.11743 Chicken Little
"You're obviously a superstar." - Christian Graus about me - 12 Feb '03
Within you lies the power for good - Use it!
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Per MSDN, read() reads the number of bytes specified by the second parameter. In this case, it reads 1 byte into charVar, but leaves the CRLF characters in the stream for the next call to read(). I think you need to use getline() instead.
LudaLuda wrote:
and I have to use the ios::binay method to open the file,
Why? From what you've shown, binary mode is not necessary.
"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)
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okey guys I got that part to work.
Now I have another problem.
how do I move the pointer so that it points to the beginning of the next record location in the file. I have several records in the file.
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seekp(...);
seekg(...);
Maxwell Chen
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LudaLuda wrote:
how do I move the pointer so that it points to the beginning of the next record location in the file. I have several records in the file.
That all depends on what a "record" is.
"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)
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I have the following code:
TCHAR * ptszVersionInfo = _T(""); //Executes OK
ptszVersionInfo = new TCHAR[10]; //Executes OK
delete ptszVersionInfo; //Executes OK
ptszVersionInfo = _T("Anton"); //Executes OK
delete ptszVersionInfo; //Weird erro. From debug assert.It basically says there is an error with _CrtIsValidHeapPointer.
Now how come. (I am not very good with string allocation  ).
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HAHAHA_NEXT wrote:
_T("Anton"); is a pointer to STATIC memory, u can't free it!
HAHAHA_NEXT wrote:
ptszVersionInfo = new TCHAR[10]; //Executes OK
delete ptszVersionInfo; //Executes OK this would rather be delete [] ptszVersionInfo;
Don't try it, just do it! 
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