C / C++ / MFC

2-May-04 8:10

You can make a COM object global with CComObjectGlobal:

CComObjectGlobal<Connection> g_connection;

--Mike--
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There is a saying in statistics that a million monkeys pounding on typewriters would eventually create a work of Shakespeare. Thanks to the Internet, we now know that this is not true.

Copy Constructor

Madmaximus2-May-04 7:45

Madmaximus

2-May-04 7:45

Hi All,
Do I need to initialize in the copy constructor too?
Example:
Foo::foo()
{
*pc = new char[5];
}

Foo::foo(cont foo& f)
{
*pc = new char[5]; // Do I need to do this here too?
Strcpy(this->pc, f.pc);
}

Thanks in advance. Wink | ;)

Re: Copy Constructor

Michael Dunn2-May-04 8:17

new programmer needs help

2-May-04 8:17

Assuming your destructor calls delete[] pc, then yes. That is the point of the copy constructor, to make a deep copy when the default behavior of a bitwise copy is insufficient.
BTW, whenever you have a copy constructor, it's a good guideline to also have an operator = as well.

--Mike--
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There is a saying in statistics that a million monkeys pounding on typewriters would eventually create a work of Shakespeare. Thanks to the Internet, we now know that this is not true.

Re: Copy Constructor

Andrew Walker2-May-04 13:21

Andrew Walker

2-May-04 13:21

I agree with Mike, however:

Try to avoid this if at all possible - but sometimes it isn't.

Rely upon your lower level tools to ensure copy semantics are enforced properly. In this example rather than using char* try to use std::string, doing so would mean that you wouldn't even have to write the copy constructor. Similarly, rather than using arrays, use std::vector, std::list or std::deque.

If you can keep you head when all about you
Are losing theirs and blaming it on you;
If you can dream - and not make dreams your master;
If you can think - and not make thoughts you aim;
Yours is the Earth and everything that's in it.

Rudyard Kipling

pvparks2-May-04 7:04

pvparks

2-May-04 7:04

hi guys, i am trying to read in CD info from a file and put it into an array, using a CD class. I have been working here for about 6-8 hours trying to get the input file into an array. i just need some help starting it. It needs to read 15 15 rows with 6 columns in each row. Any help???

thx a bunch.....

#if !defined(microsoft)
#include <stdlib.h>
#define cls() system ("cls");
#endif

#include <iostream>
#include <iomanip>
#include <fstream>
#include <conio.h>
#include <cstring>
using namespace std;

class CD
{
private:
int numberID1;
char nameArtist[20];
int numSongs;
char genderArtist[10];
float cdPrice;
char artistLabel[25];
char cdArray[15];

public:

CD(); // default constructor

void getData(); //getData
void reportData();
void getkeyedData();
~CD(); //destructor

};

CD::CD()//constructor
{
numberID1 = 0;
nameArtist[0] = '\0';
numSongs = 0;
genderArtist[0] = '\0';
cdPrice = 0;
artistLabel[0] = '\0';
}

CD::~CD()//destructor
{

}

ifstream infile;
ofstream outfile;
ofstream errorlog;

int main ()
{

void instructions();
int menu();
void printCDList(const CD[]);

CD myCD;
CD CDList[50];

int i;

int data_amt;
int response;

outfile.open("cdlist.txt");
errorlog.open("errorlog.txt");
arraytest.open("arraytest.txt");

do

{
char filename[80];

infile.clear();
cout << "Please enter the name of the file with the CD information in it: ";
cin >> filename;
infile.open(filename, ios::in);
}
while (infile.fail());

instructions();

infile>>data_amt;

for(i=1; i<=data_amt; i++)
{
cout << "CD #" << i <<endl;
="" mycd.getdata();
="" getche();
="" cdlist[i]="myCD;
" }=""

="" getche();

="" response="menu();

switch(response)
{

//case" 1:="" mycd.idsort();
="" break;

="" case="" 2:="" mycd.artistsort();
="" break;

case="" 3:="" mycd.getkeyeddata();
="" 4:="" mycd.changeprice();
="" 5:="" mycd.reportdata();
="" cout="" <<="" "printing="" report......"="" endl;
="" "please="" hit="" enter="" to="" finish="" report"="" 6:="" break;

}

="" return="" 0;
}="" end="" of="" main
="" *

="" }
="" if(menuagain[0]="='Y'||menuAgain[0]=='y')
" {
="" menu();
="" else
="" "thank="" you="" for="" using="" this="" program.="" goodbye!"="" endl;

="" 0;
}

="" **********************************************************************
="" function="" name:="" instructions
="" purpose:="" explain="" the="" user="" what="" program="" will="" do
="" parameters:
="" input:
="" input="" &="" output:
="" value:
="" non-local="" variables="" used:
="" functions="" called:
="" **********************************************************************

*=""
void="" instructions()
{
="" "this="" allow="" information="" a="" cd="" from="" keyboard="" and="" file."="" "it="" accept:="" "="" "the="" upc="" code="" on="" cd,="" artist's="" name,="" gender="" artist,="" number="" songs="" price="" label="" that="" released="" cd"="" endl;

}

int="" menu()
{

="" int="" ans;
="" do="" cls();
="" cout<<"choose="" one="" following="" options:"<<endl;
="" cout<<"1.="" sort="" display="" list="" cd's="" by="" id="" number"<<endl;
="" cout<<"2.="" artists="" name"<<="" cout<<"3.="" new="" keyboard"<<endl;
="" cout<<"4.="" change="" cd's"<<endl;
="" cout<<"5.="" create="" report="" sorted="" cout<<"6.="" exit="" program"<<endl;
="" cin="">> ans;

}
while((ans<1)||(ans>6));

return ans;
}

Re: new programmer needs help

Michael Dunn2-May-04 9:02

Re: new programmer needs help

2-May-04 9:02

Welcome to CodeProject, pvparks. Your post is unfortunately too long and hard to read so I doubt you'll get much help.
You need to do a few things. First, put <pre>...</pre> tags around the code to preserve spacing. It's also too much code, you need to narrow it down to just the part that isn't working. Finally, explain what's going wrong. Is it crashing? Giving you the wrong output? Formatting the hard drive?

--Mike--
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I think so Brain, but if we shaved our heads, we'd look like weasels!

alex.barylski2-May-04 15:58

alex.barylski

2-May-04 15:58

Michael Dunn wrote:
Finally, explain what's going wrong. Is it crashing? Giving you the wrong output? Formatting the hard drive?

That'd be funny Smile | :)

How do I print my voice mail?

Re: new programmer needs help

Ryan Binns2-May-04 18:23

Ryan Binns

2-May-04 18:23

Hockey wrote:
That'd be funny

Not for him... Unsure | :~

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

How to I include functions from another project?

jngonzalez2-May-04 6:28

jngonzalez

2-May-04 6:28

Sorry for a very basic question. I am a student and trying to learn how to add functions from another project to one I am working on. The very simple project is a test MFC project on MS VSC++ 6.0 with default options chosen. I have added the .h and .cpp files from the other project which happens to show a calendar when executed.

After that I am lost. I was told that I would have to add the following code:
AFCYearSelectWnd::create:

But the question is where and how?

All help is greatly appreciated.

John

Re: How to I include functions from another project?

valikac2-May-04 14:52

valikac

2-May-04 14:52

In general, you first create the MFC object via Resource Editor, add the C++ code to the project, and link the MFC object to the C++ class.

Kuphryn

Developer Studio issue

brdavid2-May-04 5:10

2-May-04 5:10

I'm having a rather large issue with Developer Studio where if one types out a varible name such as a class or struct or any other data type, I'm not getting any information from it. That is, when you type pVar. or pVar-> I'm not getting a combobox of information, or if I do, the information is old and is not updating.

Should I reinstall Developer Studio or is this a fix that can be done quickly? One thing and I don't know if this makes a difference. I have VC.NET installed as well. Could they be conflicting with each other?

Thanks!

C^hris L^osinger2-May-04 5:33

C^hris L^osinger

2-May-04 5:33

try deleting your project's ".NCB" file.

Cleek | Losinger Designs | ClickPic | ThumbNailer

Renjith Ramachandran2-May-04 5:42

Renjith Ramachandran

2-May-04 5:42

eventhough the cleanup of NCB will not help you..i strongly recoment you to use VISUAL ASSIST. COOOOOOOL software...thats really great...now i am using the demo version (for vS 6), that will expire soon... Frown | :(

I want to change Myself..Can u help me? Smile | :)

John R. Shaw2-May-04 5:43

John R. Shaw

2-May-04 5:43

Try deleting the .ncb file in your project directory (may be corrupt), it will be regenerated by Visual C++. Also, you might want to search for IntelliSense in the MSDN and elsewhere.

INTP

brdavid2-May-04 6:01

Variable parameters and COleVariant

2-May-04 6:01

Replacing the .ncb seemed to fix it. Thanks!

brdavid2-May-04 5:07

Re: Variable parameters and COleVariant

2-May-04 5:07

I had a similar issue before and fixed up the code per instructions given to me, however I still have an issue with it. The code is as follows

<code>
CString CXMLParser::CreateAttributeTag(bool End, CString TagName, COleVariant *Value, ...)
{
	va_list argList;
	int count = 0;

	CString returnVal = _T("");

	va_start(argList, Value);
	
	for(;;)
	{
		CString AttributeName = va_arg(argList, LPCTSTR);
		//AttributeName = ConvertValueToString(&pVar); 

		if(AttributeName.IsEmpty())	break;

		CString AttributeValue = va_arg(argList, LPCTSTR);
		//CString AttributeValue = ConvertValueToString(&pVar);

		returnVal += AttributeName +"=\'"+ AttributeValue +"\' ";
	}

	va_end(argList);

	return FormatTag(End, TagName, Value, returnVal);
}
</code>

I want to provide a function that will take variable parameters so I can build an attribute list for an XML tag. This function is the function I call with the variable parameters. When var_arg is called I get corrupted data.

Another question I had was, I saw CString Format uses a LPCTSTR variable where each parameter could be a different type, that is one parameter could be an int, another a double and another a string. Since I want the same to work here, is it proper to employ the same tactic or should I use COleVariant?

Thanks!

Michael Dunn2-May-04 5:57

Re: Variable parameters and COleVariant

2-May-04 5:57

You need to have a way to tell the function how many parameters are in the ... part, and their types. Since you want to have any number and differing types, you will need something rather complex - copying the format string method used by CString::Format() wouldn't be the worst way to do it.

--Mike--
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brdavid2-May-04 6:25

Re: Variable parameters and COleVariant

2-May-04 6:25

thanks for the info... quick question.. From where do I get the value of how long it is. Do I passs that myself or can that be determined programmically?

Thanks!

Michael Dunn2-May-04 6:34