我有一个C ++项目需要编辑。这是变量的声明:
// Attachment
OFSTRUCT ofstruct;
HFILE hFile = OpenFile( mmsHandle->hTemporalFileName , &ofstruct , OF_READ );
DWORD hFileSize = GetFileSize( (HANDLE) hFile , NULL );
LPSTR hFileBuffer = (LPSTR)GlobalAlloc(GPTR, sizeof(CHAR) * hFileSize );
DWORD hFileSizeReaded = 0;
ReadFile( (HANDLE) hFile , hFileBuffer, hFileSize, &hFileSizeReaded, NULL );
CloseHandle( (HANDLE) hFile );
我需要检查文件是否附加(我想我需要检查hFile是否有任何值),但不知道如何。我试过hFile == NULL
,但这不起作用。
谢谢,
ILE
答案 0 :(得分:6)
将hFile与HFILE_ERROR进行比较(不是NULL!)。此外,您应该将OpenFile更改为CreateFile并正确调用它,OpenFile早已被弃用。事实上,MSDN明确指出:
OpenFile功能
仅使用16位的此功能 Windows版本。对于更新的 应用程序,使用CreateFile 功能
当您进行此更改时,您将获得一个HANDLE,您应该将其与INVALID_HANDLE_VALUE进行比较。
更新:获取文件大小的正确方法:
LARGE_INTEGER fileSize={0};
// You may want to use a security descriptor, tweak file sharing, etc...
// But this is a boiler plate file open
HANDLE hFile=CreateFile(mmsHandle->hTemporalFileName,GENERIC_READ,0,NULL,
OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);
if (hFile!=INVALID_HANDLE_VALUE && GetFileSizeEx(hFile,&fileSize) &&
fileSize.QuadPart!=0)
{
// The file has size
}
else
{
// The file is missing or size==0 (or an error occurred getting its size)
}
// Do whatever else and don't forget to close the file handle when done!
if (hFile!=INVALID_HANDLE_VALUE)
CloseHandle(hFile);
答案 1 :(得分:1)
在打开文件之前,您可以尝试:
WIN32_FIND_DATA wfd;
HANDLE h = FindFirstFile(filename, &wfd);
if (h != INVALID_FILE_HANDLE)
{
// file exists
if (wfd.nFileSizeHigh != 0 || wfd.nFileSizeLow != 0)
{
// file is not empty
}
FindClose(h)
}