Managed C++/CLI

23-Oct-05 0:23

how do you print it ?

using printf("%2d", minutes); would help...

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Re: rookie question

Christian Graus23-Oct-05 12:55

23-Oct-05 12:55

That sucks - you have to either use some relatively advanced C++ stuff in iostreams, or use C ( i.e. use printf ).

Christian Graus - Microsoft MVP - C++

Re: rookie question

toxcct24-Oct-05 1:16

Accessing external devices(I don't have any idea)

24-Oct-05 1:16

Christian Graus wrote:
That sucks

it was only a suggestion. i never said to use it and nothing else...

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Alex Cutovoi21-Oct-05 6:01

Alex Cutovoi

21-Oct-05 6:01

Hi for all

I started to study how I can access external devices in C++. I've entered in MSDN and I've found a thing called HID Collections. By the description of MSDN, HID Collections are a meaningful group of HID controls and HID usages. HID Controls are a data sources and data sinks associated with a HIDClass device. After this description I don't know if this way is correct to study device access.
Iwould like an orientation about this topic. Someone can put a little bit of light in this topic for me? I'm totally newbie in this.

Thanks a lot

Fastest way to check a file exists

[d3m0n]21-Oct-05 4:32

[d3m0n]

21-Oct-05 4:32

Hi My app stalls at startup because a file in the MRU list is on a network drive that doesn't exist.
The exact filename I am trying to add is "\\blah\start.txt".
I call CRecentFileList::Add from InitInstance. This Add function goes away for about 10secs before returning failure.
So I changed my code so that the Add function is only called if the file actually exists. But every function I tried (PathFileExists, _access, CFile::Open etc etc) always stalls for these 10secs.
There must be some function I can use that will check a file exists, which returns immediately... Confused | :confused:

Any ideas?

Thanks

d3m0n

toxcct21-Oct-05 4:44

21-Oct-05 4:44

what's your code please ?

these functions are not so long for me...

TOXCCT >>> GEII power
[toxcct][VisualCalc]

[d3m0n]21-Oct-05 5:00

[d3m0n]

21-Oct-05 5:00

<br />
for (POSITION pos = listFiles.GetHeadPosition(); pos; )<br />
{<br />
	CString strFile = listFiles.GetNext(pos);<br />
	if (_access(strFile, 0) != -1)	//takes 10secs if strFile is "\\blah\start.txt"<br />
		m_pmruFiles->Add(strFile);<br />
}<br />

This problem only occurs if I am connected to the network. If disconnected, it returns failure immediately.

toxcct23-Oct-05 0:22

23-Oct-05 0:22

this is not a problem a the function but the network access...

if you open a windows explorer and reach the networks around you, explorer will take several seconds to show you the first infos...

TOXCCT >>> GEII power
[toxcct][VisualCalc]

[d3m0n]23-Oct-05 21:37

[d3m0n]

23-Oct-05 21:37

toxcct wrote:
this is not a problem a the function but the network access...

Yes I have come to the same conclusion. I think it is impossible to solve this problem.

Thanks for your help Smile | :)

Cheers
d3m0n

Upcasting

LiYS21-Oct-05 0:27

LiYS

21-Oct-05 0:27

I wonder why the upcasting only can happened to public inheritance? D'Oh! | :doh:

like:

#include <iostream>
#include <fstream>
#include <string>
using namespace std;
class Base
{
public:
};

class Pri : private Base
{
public:
protected:
private:
};

class Pro :protected Base
{
public:
protected:
private:
};
void func(Base* n){}
int main() 
{
	Pro pro;
	Pri pri;
//	func(&pri); //error with the message "conversion from 'class Pri *' to 'class Base *' exists, but is inaccessible"

}

Re: Upcasting

Christian Graus23-Oct-05 12:57

Which one is faster a fstream or FILE

23-Oct-05 12:57

That's what private means.

Christian Graus - Microsoft MVP - C++

Member 52815520-Oct-05 20:22

Member 528155

20-Oct-05 20:22

Hi,
I want to introduce Logs in my c++ program. which is faster fstream or 'c' language's FILE ? so that i can use in my logs.

Thanx in adv.

lokiz

toxcct20-Oct-05 21:49

20-Oct-05 21:49

FILE is not a method but only a structure. so, it doesn't perform any action, and we cannot calculate a duration on it...
i think you wanted to ask for fstream methods compared with C file handling functions (fopen(), fclose(), fread(), fwrite(), fprintf(), fscanf(), ...)

insn't it ?

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Member 52815520-Oct-05 22:36

Member 528155

20-Oct-05 22:36

yes TOX u r right. which is faster fstream methods or C file handling functions................

lokiz

Nemanja Trifunovic22-Oct-05 5:26

Nemanja Trifunovic

22-Oct-05 5:26

C io library is faster. But if you want really fast IO, you should better use directly Windows API

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.

Christian Graus23-Oct-05 12:57

comparing directory contents

23-Oct-05 12:57

You're asking the wrong question. FILE is C, fstream is C++. You should use C++ if your app is in C++, even if it takes a microsecond longer. Reasons - extensibility and ability to write good code.

Christian Graus - Microsoft MVP - C++

mcmahoncm20-Oct-05 14:36

mcmahoncm

20-Oct-05 14:36

I would like to write some code to compare the files within a directory with a 2nd directory and see which files are either not in the 2nd dir or have been changed. The aim of which is to basically duplicate the contents of a directory to another but only changing what is essential, as I will be sending the files over the internet.

Sorry, I know that wasn't very clear, but hopefully someone will understand what I want to find out!

Thanks in advance,
-Caolan

Why Error???

ashok12320-Oct-05 10:05

ashok123

20-Oct-05 10:05

I am not sure why I am getting error in displaying the output. I want output such that when I enter a string aaaabaaba... for "aaa" it shud give output 0 and "aba" it should give output 1. I am not sure where the error is??? Please help thanks is advance.

#include<iostream.h>
#include<stdio.h>
#include<string.h>
#include<windows.h>

char* in;
void main()
{
cout << "Enter your string here \n";
cin>>in;
while(*in != ' ') //it crashes here
{
if(strncmp(in, "aaa", 3)==0)
cout << "0";
if(strncmp(in, "aba", 3)==0)
cout << "1";
in+=3;
}

}

A

Re: Why Error???

Christian Graus20-Oct-05 10:15

20-Oct-05 10:15

ashok123 wrote:
char* in;

This sets aside the memory to store an address, but it does not actually create a block of memory to store your string to. You have a pointer, but it's not pointing to anything.

ashok123 wrote:
while(*in != ' ') //it crashes here

This code is wrong on a number of levels. First of all, it requires that the string have a space in it. Secondly, because you step by three further down, it assumes that the string will be either a space, or characters in a multiple of three, and then a space. The easiest way to solve all of this is to use std::string instead of a char *, and then use std::string's functions to check the contents of the string.

Christian Graus - Microsoft MVP - C++

Re: Why Error???

ashok12321-Oct-05 3:30

ashok123

21-Oct-05 3:30

Thanks Chris... Big Grin | :-D

Copy File

ferhattt8420-Oct-05 9:02

ferhattt84

20-Oct-05 9:02

Hi friends
how copy my *.* files
target folder or other place please tell me copy code for C++

Re: Copy File

Christian Graus20-Oct-05 10:12

RemoveAt() is growing a queue

20-Oct-05 10:12

FindFirstFile and FindNextFile can be used to find the files, and CopyFile can be used to copy them.

Christian Graus - Microsoft MVP - C++

CaCaPe20-Oct-05 8:50

CaCaPe

20-Oct-05 8:50

Hi. I use RemoveAt() to remove objects from a list every time a given object attribute reach a certain value. The problem is that the objects are reaching the point faster than RemoveAt() can remove them from list, so there's a huge queue growing. Anybody knows how I could fix it? Confused | :confused:

CaCaPe

Re: RemoveAt() is growing a queue

Christian Graus20-Oct-05 10:22