I'm new here and my english is not really good. Apologize any inconvenience!
I'm programming an application for windows mobile with native code (MFC). I'm trying to open a file and this is driving me crazy. I've tried to open it in a thousand diferent ways... And I really achieve it, but when I try to read (fread
or getline
) the program crashes without any explanation:
The program 'x' finalize with code 0 (0x0)
The GetLastError()
method, in some cases, returns me a 183.
Then, I put the code I've used to open the file:
std::wifstream file(L"\\Archivos de programa\\Prog\\properties.ini");
wchar_t lol[100];
if (file) {
if(!file.eof()) {
file.getline(lol,99);
}
}
It enters on all th开发者_StackOverflow中文版e if's, but the getline crashes.
FILE * lol = NULL;
lol = _wfope n(ruta, L"rb");
DWORD a = GetLastError();
if ( lol != NULL )
return 1;
else
return -1;
It returns 1 (correct), and after, in a later getline, it stores trash on the string. However, it doesn't crash!!
fp.open (ruta, ifstream::in);
if ( fp.is_open() ) {
return 1;
}else{
return -1;
}
It enters on the return 1, but when executing the later getline() crashes.
I've debugged the getline()
method and it crashes on the library fstream
, right there:
if ((_Meta = fget c (_File)) == EOF)
return (false);
In the if. The fgetc()
, I supose.
I'm going completely crazy!! I need some clue, please!!
The path of the file is correct. First, because, in theory, the methods open the file, and second, I obtain the path dinamically and it matches.Emphasize that the fread
method also crashes.
Thanks in advance!
P.S.:
Say that when I do any fopen, the method fp.good() returns me FALSE, and the GetLastError returns me 183. By the other hand, if I usefp.fopen(path, ifstream::in);
or std::wifstream fp(path);
the fp.good();
returns me TRUE
, and the GetLastError()
doesn't throw any error (0).A hint: use the Process Monitor tool to see what goes wrong in the file system calls.
The path accepted by wifstream
is lacking a drive ("C:" or the like) (I don't know what the ruta
variable points to)
Apart from the streams problem itself, you can save yourself a lot of trouble by using the GetProfileString
and related functions, when using a windows .ini file.
I'm shooting in the dark here, but your description sounds like a runtime mismatch story. Check that MFC and your project use the same runtime link model (static/dynamic). If you link to MFC dynamically, then the restriction is stricter: both MFC and your project have to use dynamic runtime.
I don't know why, but with the CFile class... it works...
Programming mysteries!
Shooting in the dark too. Unexplained random crash in MFC often comes from a mismatch message handler prototype. For example the following code is wrong but it won't generate any warning during compilation and it may work most of the time :
ON_MESSAGE(WM_LBUTTONDOWN, onClick)
...
void onClick(void) //wrong prototype given the macro used (ON_MESSAGE)
{
//do some stuff
}
Here the prototype should be :
LRESULT onClick(WPARAM, LPARAM)
{
}
It often happens when people get confident enough to start modifying manually the message maps.
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