Help with code used for reading in a file

[lemming999]

Hi, very novice programmer here, When I run this function, it prints out the first messageBox (ie when count == 0 but it doesn't go to the next messageBox, i know that they're are more than 1 entry in the file I'm loading.

any ideas, its very similar to code that i got to work with a static text outputting program




while (!DataIn.eof()) // While more entries
{
int count;
DataIn.read((char*)&entry,sizeof(DataIn));

if(DataIn.eof()) //eof not set till after end
break;

if(count == 0)
{
strcpy(First.name,entry.name);
MessageBox(hwnd, First.name, TEXT("HelloMsg&quot, 0);
count++;
}
else
{
strcpy(Current.name,entry.name);
MessageBox(hwnd, Current.name, TEXT("HelloMsg&quot, 0);

}
}
DataIn.clear(); // Reset eof flag
return TRUE;
}




Thanks,
Brian

 

[Orcbighter]

Your problem is that the count variable is inside the while loop, so each iteration re-initialises it back to zero.

your code ...

while (!DataIn.eof()) // While more entries
{
int count;
DataIn.read((char*)&entry,sizeof(DataIn));
...
}

should read

int count = 0;
while (!DataIn.eof()) // While more entries
{
DataIn.read((char*)&entry,sizeof(DataIn));
...
}

another novice mistake would be to make the count variable a static variable.
eg:

while (...)
{
static int count = 0;
...
}

This is sloppy because, while it will stop the re-initialisation on each loop iteration, it causes resources to be permanently alloocated for the liofe of the program, rather than the life of the function doing the WHILE. It would be bad programming.