C / C++ / MFC

Arman S.13-Jun-07 6:18

Arman S.

13-Jun-07 6:18

cur_data should end-up with NULL as you are adding NULL to it from the beginning.

The following will work;

char buffer[1];
char cur_char;
CString cur_data;
UINT bytesread = 0;
do
{	
bytesread += radardata.Read(buffer,1);
cur_char=buffer[0];

cur_data += cur_char;
}
while (cur_char != ',');

--
=====
Arman

penny black14-Jun-07 3:34

penny black

14-Jun-07 3:34

That worked, thanks!

David Crow13-Jun-07 6:21

13-Jun-07 6:21

pkoelsch wrote:
Trying to read a text file one character at a time.

You do realize how inefficient this is, don't you?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: problem with ifstream

penny black14-Jun-07 3:36

penny black

14-Jun-07 3:36

Like I said, I'm new to VC++. No classes, just opened a book. The last time I did any formal computer programming, we still used line numbers. I'm open to any recommendations.

problem with ifstream

Yonggoo13-Jun-07 5:42

Yonggoo

13-Jun-07 5:42

Hi All,
I always appreciate your help.

I have a problem with ifstream
This is my 'input.txt' file.
The first digit of each line is the length.
How can I read in this file using while() or for()

2 3 4
5 7 8 10 11 12
7 8 10 16 17 54 37 38
3 33 51 48
...

I tried this one.
...
ifstream inpf_EX("input.txt");
for (i=1; i<=N_Of_LINE;i++)
{
inpf_EX>>EXIST[i][0]);
len=EXIST[i][0];
for(j=1; j<=len; j++)
{
inpf_EX>>EXIST[i][j]);
}
}

Thanks!
...

Yonggoo

David Crow13-Jun-07 5:57

Re: problem with ifstream(more details?)

13-Jun-07 5:57

Yonggoo wrote:
How can I read in this file using while() or for()

Neither are necessary, and their use would only serve to confuse you further. You can use an iterator on a stringstream object, and then use the copy() function. You don't need an extra digit in the front to tell how many items follow. If it has to stay, however, just read it in and ignore it.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Yonggoo13-Jun-07 6:03

Yonggoo

13-Jun-07 6:03

I have not used an iterator on a stringstream.
Does std c++ have iterator?

Thanks!

Yonggoo

Re: problem with ifstream(more details?)

David Crow13-Jun-07 6:16

Visual Studio debugger telling me wrong information

13-Jun-07 6:16

Yonggoo wrote:
Does std c++ have iterator?

Yes.

class LineItem
{
public:
    LineItem() {}
    ~LineItem() {}
 
    void setLength(const int length) { _Length = length; }
    int getLength() const { return _Length; }
 
    void setNumbers(const std::vector<int>& numbers) { _Numbers.assign(numbers.begin(), numbers.end()); }
    std::vector<int> getNumbers() const { return _Numbers; }
private:
    int _Length;
    std::vector<int> _Numbers;
};
 
std::ostream& operator<<(std::ostream& os, const LineItem& s)
{
    os << s.getLength() << "|";
 
    const std::vector<int> numbers = s.getNumbers();
    std::copy(numbers.begin(), numbers.end(), std::ostream_iterator<int>(os, " "));
	
    os << std::endl;
	
    return os;
}
 
std::istream& operator>>(std::istream& is, LineItem& s)
{
    int length;
    is >> length;
 
    std::string sNumbers = "";
    std::getline(is, sNumbers);
 
    std::stringstream ss(sNumbers);
 	
    std::vector<int> numbers;
    std::copy(std::istream_iterator<int>(ss), std::istream_iterator<<int>(), std::back_inserter(numbers));
    
    s.setLength(length);
    s.setNumbers(numbers);
	
    return is;
}
 
void main( void )
{
    std::ifstream fin;
    std::vector<LineItem> lines;
	
    fin.open("c:\\input.txt");
    std::copy(std::istream_iterator<LineItem>(fin), std::istream_iterator<LineItem>(), std::back_inserter(lines));
    fin.close();
 
    std::copy(lines.begin(), lines.end(), std::ostream_iterator<LineItem>(std::cout, "\n"));
}

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Cyrilix13-Jun-07 5:35

Re: Visual Studio debugger telling me wrong information

13-Jun-07 5:35

The following is my code for when I click on a button that's labeled "Start". I use a functor to call my class member function pointer (via Execute(), where Execute() takes an int& parameter). When I set a breakpoint at the Execute() calls, and I hover my mouse over "i", the MSVC debugger tells me that i has some really high value like 4632955, and when I check &i in the immediate window, it tells me the memory address of i. Then, I go into Execute() to call the specific function pointer &MainWindow::DoWork, when I check the input parameter (which takes an int& as mentioned earlier), the memory address of that input parameter is &i + 4 bytes. Basically, what I'm saying is that MSVC shows me different memory address values from the calling function ButtonStart() and within the called function DoWork(). The value from ButtonStart() is wrong, as my int is not some really high number, but the value that is actually received in DoWork() is right, and ends up being 5 (what I set it to in the beginning). This is the first problem and I don't know why this is happening.

The second problem is that some of my lines of execution are being skipped. Actually, that is inaccurate, as they are being executed but I cannot set a breakpoint at some of the lines such as the line int i = 5. MSVC will just shift my breakpoint down to the Execute() calls. My debugging info is turned on, and I'm am building in Debug mode, so this shouldn't happen (I've had it happen when building in Release mode).

void MainWindow::ButtonStart()
{
	if (!m_threadPool && !m_source && !m_receiver)
	{
		//Initialize thread handler
		m_source = new EventSource();
		m_receiver = new EventReceiver();
		m_threadPool = new ThreadPool(m_source, m_receiver);

		//Hook thread handler termination event
		m_receiver->HookThreadPool(m_source);

		int i = 5;
		CallbackWrapperSpecific<MainWindow, void (MainWindow::*)(int&), int> cbwsPtr(this, &MainWindow::DoWork);
		CallbackWrapperBase<int>* cbwbPtr = &cbwsPtr;
		cbwbPtr->Execute(i);
		cbwbPtr->Execute(i);
	}
}

David Crow13-Jun-07 6:19

Re: Visual Studio debugger telling me wrong information

13-Jun-07 6:19

Is a Rebuild All in order?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Cyrilix13-Jun-07 6:35

Problem Fixed -- optimization (/O2) causes these problems

13-Jun-07 6:35

Yep, I've done multiple cleans and rebuilds -- still no luck. I wonder if I've corrupted the memory somewhere... or I need to enable some kind of extra flag for debugging MFC Multithreaded applications, etc.

Cyrilix13-Jun-07 6:49

Re: Problem Fixed -- optimization (/O2) causes these problems

13-Jun-07 6:49

Bah, it was just optimizing for maximum speed (which was a default setting) that caused these problems... I turned it off (/Od) and now I can see everything the way I want to for a debug version.

David Crow13-Jun-07 6:53

Re: Problem Fixed -- optimization (/O2) causes these problems

13-Jun-07 6:53

Cyrilix wrote:
Bah, it was just optimizing...

In debug mode?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Cyrilix13-Jun-07 7:02