this is a followup on 'LPCTSTR typecast for use with GetFileAttributes'
i extended my method by GetLastError();.
I cast DWORD into a unsigned int and try to display it with a MessageBox.
the code does work, but i fail to visualize the value of DWORD dw or Unsigned int test from the GetLastError(); method using a MessageBox and figuring how to proceed.
this a win32 project and i trying to build a method to see if a file exist on the harddrive.
there are over 15.000 error codes and it´s imposible to hardcode them all. http://msdn.microsoft.com/en-us/library/windows/desktop/ms681381(v=vs.85).aspx
BOOL FileExists(LPCTSTR szPath)
{
//MessageBox(NULL,szPath,L"File Error",MB_OK);
DWORD dwAttrib = GetFileAttributes(szPath);
unsigned int test;
DWORD dw = GetLastError();
test =(unsigned int)dw;
if(test == 0){
MessageBox(NULL,(LPCWSTR)test, L"Target == 0",MB_OK);
}
else
{
MessageBox(NULL,(LPCWSTR)test, L"Target != 0",MB_OK);
}
switch(dw)
{
case ERROR_SUCCESS:
MessageBox(NULL,L"ERROR_SUCCESS", L"File Error",MB_OK);
break;
case ERROR_PATH_NOT_FOUND:
MessageBox(NULL,L"ERROR_PATH_NOT_FOUND", L"File Error",MB_OK);
break;
default:
MessageBox(NULL,(LPCWSTR)dw, L"File Error",MB_OK);
break;
}
switch(dwAttrib)
{
case FILE_ATTRIBUTE_DIRECTORY:
MessageBox(NULL,L"FILE_ATTRIBUTE_DIRECTORY", L"File Error",MB_OK);
break;
case FILE_ATTRIBUTE_ARCHIVE:
MessageBox(NULL,L"FILE_ATTRIBUTE_ARCHIVE", L"File Error",MB_OK);
break;
case FILE_READ_ONLY_VOLUME:
MessageBox(NULL,L"FILE_READ_ONLY_VOLUME", L"File Error",MB_OK);
break;
case FILE_INVALID_FILE_ID:
MessageBox(NULL,L"FILE_INVALID_FILE_ID", L"File Error",MB_OK);
break;
//case INVALID_FILE_ATTRIBUTES:
// MessageBox(NULL,L"INVALID_FILE_ATTRIBUTES",L"File Error",MB_OK);
// break;
//case FILE_INVALID_FILE_ID:
// MessageBox(NULL,L"Failed to get image file,\\please check game folder",L"File Error",MB_OK);
// break;
default:
MessageBox(NULL,(LPCWSTR)dwAttrib,L"File Error",MB_OK);
break;
}
return true; // testing phase
}
You cannot type-cast a DWORD into a string. You have to format it.
Your error checking is wrong.
On success, GetFileAttributes() can (and frequently does) return multiple attributes at a time, but you are not handling that possibility. And some of the values you are checking for are not even value attributes to begin with.
Try this instead:
BOOL FileExists(LPCTSTR szPath)
{
DWORD dwAttrib = GetFileAttributes(szPath);
if (dwAttrib == INVALID_FILE_ATTRIBUTES)
{
DWORD dw = GetLastError();
switch (dw)
{
case ERROR_PATH_NOT_FOUND:
MessageBoxW(NULL, L"ERROR_PATH_NOT_FOUND", L"File Error", MB_OK);
break;
case ERROR_FILE_NOT_FOUND:
MessageBoxW(NULL, L"ERROR_FILE_NOT_FOUND", L"File Error", MB_OK);
break;
default:
{
std::wstringstream msg;
msg << L"Error Code: " << dw;
LPWSTR lpMsg = NULL;
if (FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_ALLOCATE_BUFFER, NULL, dw, 0, (LPWSTR)&lpMsg, 0, NULL))
{
msg << std::endl << lpMsg;
LocalFree(lpMsg);
}
MessageBoxW(NULL, msg.str().c_str(), L"File Error", MB_OK);
break;
}
}
return false;
}
else
{
std::wstringstream attribs;
if (dwAttrib & FILE_ATTRIBUTE_READONLY)
{
attribs << L"FILE_ATTRIBUTE_READONLY" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_READONLY;
}
if (dwAttrib & FILE_ATTRIBUTE_HIDDEN)
{
attribs << L"FILE_ATTRIBUTE_HIDDEN" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_HIDDEN;
}
if (dwAttrib & FILE_ATTRIBUTE_SYSTEM)
{
attribs << L"FILE_ATTRIBUTE_SYSTEM" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_SYSTEM;
}
if (dwAttrib & FILE_ATTRIBUTE_DIRECTORY)
{
attribs << L"FILE_ATTRIBUTE_DIRECTORY" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_DIRECTORY;
}
if (dwAttrib & FILE_ATTRIBUTE_ARCHIVE)
{
attribs << L"FILE_ATTRIBUTE_ARCHIVE" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_ARCHIVE;
}
if (dwAttrib & FILE_ATTRIBUTE_DEVICE)
{
attribs << L"FILE_ATTRIBUTE_DEVICE" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_DEVICE;
}
if (dwAttrib & FILE_ATTRIBUTE_NORMAL)
{
attribs << L"FILE_ATTRIBUTE_NORMAL" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_NORMAL;
}
if (dwAttrib & FILE_ATTRIBUTE_TEMPORARY)
{
attribs << L"FILE_ATTRIBUTE_TEMPORARY" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_TEMPORARY;
}
if (dwAttrib & FILE_ATTRIBUTE_SPARSE_FILE)
{
attribs << L"FILE_ATTRIBUTE_SPARSE_FILE" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_SPARSE_FILE;
}
if (dwAttrib & FILE_ATTRIBUTE_REPARSE_POINT)
{
attribs << L"FILE_ATTRIBUTE_REPARSE_POINT" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_REPARSE_POINT;
}
if (dwAttrib & FILE_ATTRIBUTE_COMPRESSED)
{
attribs << L"FILE_ATTRIBUTE_COMPRESSED" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_COMPRESSED;
}
if (dwAttrib & FILE_ATTRIBUTE_OFFLINE)
{
attribs << L"FILE_ATTRIBUTE_OFFLINE" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_OFFLINE;
}
if (dwAttrib & FILE_ATTRIBUTE_NOT_CONTENT_INDEXED)
{
attribs << L"FILE_ATTRIBUTE_NOT_CONTENT_INDEXED" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_NOT_CONTENT_INDEXED;
}
if (dwAttrib & FILE_ATTRIBUTE_ENCRYPTED)
{
attribs << L"FILE_ATTRIBUTE_ENCRYPTED" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_ENCRYPTED;
}
if (dwAttrib & FILE_ATTRIBUTE_VIRTUAL)
{
attribs << L"FILE_ATTRIBUTE_VIRTUAL" << std::endl;
dwAttrib &= ~FILE_ATTRIBUTE_VIRTUAL;
}
if (dwAttrib != 0)
attribs << L"Other: " << std::hex << std::showbase << std::setw(8) << std::setfill(L'0') << dwAttribs << std::endl;
MessageBoxW(NULL, attribs.str().c_str(), L"File Attributes", MB_OK);
return true;
}