csvwrite函数用法？
WriteFile函数通常是将数据写入到内部缓冲区，然后OS会定期将缓冲区中的数据写入到磁盘。如果想在调用WriteFile之后，数据就立即写入磁盘，有如下三种方法：
1.调用FlushFileBuffers(hFile);Flushesthebuffersofaspecifiedfileandcausesallbuffereddatatobewrittentoafile.BOOLFlushFileBuffers(HANDLEhFile//openhandletofilewhosebuffersaretobeflushed);该函数会将指定文件的缓存数据写入磁盘。
2.在用CreateFile创建文件的时候,第6个参数使用标志FILE_FL***_WRITE_THROUGHInstructstheoperatingsystemtowritethroughanyintermediatecacheandgodirectlytodisk.Theoperatingsystemcanstillcachewriteoperations,butcannotlazilyflushthem.
3.关闭掉句柄CloseHandle(hFile);
VB自定义openfile函数？
Private Declare Function OpenFile Lib "kernel32" (ByVal lpFileName As String, lpReOpenBuff As OFSTRUCT, ByVal wStyle As Long) As Long
Private Declare Function WriteFile Lib "kernel32" (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToWrite As Long, lpNumberOfBytesWritten As Long, lpOverlapped As Long) As Long
Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
Private Type OFSTRUCT
cBytes As Byte
fFixedDisk As Byte
nErrCode As Integer
Reserved1 As Integer
Reserved2 As Integer
szPathName As String * 128
在c#中readfile是什么意思？
ReadFile函数从文件指针指定的位置读取数据。读操作完成后，文件指针将根据实际读出的数据自动进行调整，除非文件句柄是以OVERLAPPED属性值打开的。如果是以OVERL***ED打开的I/O，应用程序就需要自己手动调整文件指针。这个函数被设计成兼有同步和异步操作。
ReadFileEx函数则设计成只支持异步操作，异步操作允许应用程序在读文件期间可以同时进行其他的操作。函数原型：
BOOL ReadFile(HANDLE hFile, // handle to fileLPVOID lpBuffer, // data bufferDWORD nNumberOfBytesToRead, // number of bytes to readLPDWORD lpNumberOfBytesRead, // number of bytes readLPOVERL***ED lpOverl***ed // overl***ed buffer);
