转载:http://www.cnblogs.com/doublesnke/archive/2011/08/16/2141374.html
VC++实施文件监控：实例和详解
相关帮助: http://hi.baidu.com/jiahaosoft/blog/item/b441d1218eebece0d6cae274.html
我这里只介绍采用ReadDirectoryChangesW对文件目录实施监控
关键代码
CfgdsgDlg * dlg = (CfgdsgDlg*)lparam; HANDLE hDir;
char notify[1024];
DWORD cbBytes,i;
char AnsiChar[3];
wchar_t UnicodeChar[2];
CString path;
FILE_NOTIFY_INFORMATION *pnotify=(FILE_NOTIFY_INFORMATION *)notify;
FILE_NOTIFY_INFORMATION *tmp;
GetCurrentDirectory(MAX_PATH,path.GetBuffer(MAX_PATH+1));
hDir = CreateFile( path, FILE_LIST_DIRECTORY,
FILE_SHARE_READ |
FILE_SHARE_WRITE |
FILE_SHARE_DELETE, NULL,
OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS |
FILE_FLAG_OVERLAPPED, NULL);
if (hDir == INVALID_HANDLE_VALUE)
{
dlg->m_edit.ReplaceSel("hDir:INVALID_HANDLE_VALUE\r\n");
return 0;
}
while (TRUE)
{
if(ReadDirectoryChangesW(hDir, ¬ify, sizeof(notify),
FALSE, FILE_NOTIFY_CHANGE_FILE_NAME| FILE_NOTIFY_CHANGE_LAST_WRITE,
&cbBytes, NULL, NULL))
{
tmp = pnotify;
switch(tmp->Action)
{
case FILE_ACTION_ADDED:
dlg->m_edit.ReplaceSel("Directory/File added （添加文件）- \r\n");
break;
case FILE_ACTION_REMOVED:
dlg->m_edit.ReplaceSel("Directory/File removed （删除文件）- \r\n");
break;
case FILE_ACTION_MODIFIED:
dlg->m_edit.ReplaceSel("Directory/File modified （修改文件内容）- \r\n");
break;
case FILE_ACTION_RENAMED_OLD_NAME:
dlg->m_edit.ReplaceSel("Directory/File old name （修改文件名字）- \r\n");
break;
case FILE_ACTION_RENAMED_NEW_NAME:
dlg->m_edit.ReplaceSel("Directory/File new name - \r\n");
break;
default:
break;
}
}
}
|
FILE_NOTIFY_INFORMATION //可以确定是那个文件进行的修改
typedef struct _FILE_NOTIFY_INFORMATION {
DWORD NextEntryOffset;
DWORD Action;//动作
DWORD FileNameLength;//文件名字的长度
WCHAR FileName[1];//文件名字
} FILE_NOTIFY_INFORMATION,
*PFILE_NOTIFY_INFORMATION;
ReadDirectoryChangesW 返回类型(见MSDN)
| Value | Meaning |
|---|---|
|
FILE_ACTION_ADDED |
The file was added to the directory. |
|
FILE_ACTION_REMOVED |
The file was removed from the directory. |
|
FILE_ACTION_MODIFIED |
The file was modified. This can be a change in the time stamp or attributes. |
|
FILE_ACTION_RENAMED_OLD_NAME |
The file was renamed and this is the old name. |
|
FILE_ACTION_RENAMED_NEW_NAME |
The file was renamed and this is the new name. |
效果如下：
不足的地方:
只能检测到指定目录和下一级目录，超过目录级数，该函数检测不到。
2. 转载:http://blog.csdn.net/visualeleven/article/details/7562014
// .h文件
#pragma once typedef void (*PFN_NotifyAction)(DWORD dwAction, LPWSTR szFile, DWORD dwLength); class CDirectoryWatch
{
public:
CDirectoryWatch(void);
virtual ~CDirectoryWatch(void); public:
BOOL StartDirectoryWatch(LPCTSTR lpszDirectory, PFN_NotifyAction pFn_NotifyAction);
BOOL StopDirectoryWatch(void); private:
static UINT __cdecl ThreadProc(LPVOID lParam);
static UINT __cdecl DirectoryWatch(LPVOID lParam); private:
HANDLE m_hFile;
CWinThread* m_pThread;
TCHAR m_szDirectory[MAX_PATH];
};
// .cpp文件
#include "StdAfx.h"
#include "DirectoryWatch.h"
#include <strsafe.h> typedef enum
{
MSG_STARTWATCH = (WM_USER + 0x11),
MSG_STOPWATCH,
MSG_EXITTHREAD
}; #define MAX_BUFFER_SIZE (1024) typedef struct _tagWATCHPARAMETERS
{
_tagWATCHPARAMETERS()
{
hFile = INVALID_HANDLE_VALUE;
hEvent = NULL;
memset(&ol, , sizeof(OVERLAPPED));
pBuffer = NULL;
dwBufferSize = ;
bExit = FALSE;
pFn_NotifyAction = NULL;
}
HANDLE hFile;
HANDLE hEvent;
OVERLAPPED ol;
BYTE* pBuffer;
DWORD dwBufferSize;
BOOL bExit;
PFN_NotifyAction pFn_NotifyAction;
}WATCH_PARAMETERS, *PWATCH_PARAMETERS; CDirectoryWatch::CDirectoryWatch() : m_hFile(INVALID_HANDLE_VALUE), m_pThread(NULL)
{
memset(m_szDirectory, , sizeof(m_szDirectory)); m_pThread = AfxBeginThread(ThreadProc, NULL, , CREATE_SUSPENDED, , NULL);
if(NULL == m_pThread)
{
TRACE("Error Code : %d\n", GetLastError());
return ;
}
m_pThread->m_bAutoDelete = FALSE;
m_pThread->ResumeThread();
} CDirectoryWatch::~CDirectoryWatch()
{
if(INVALID_HANDLE_VALUE != m_hFile)
{
CloseHandle(m_hFile);
m_hFile = INVALID_HANDLE_VALUE;
} if((NULL != m_pThread) && (NULL != m_pThread->m_hThread))
{ m_pThread->PostThreadMessage(MSG_EXITTHREAD, , );
WaitForSingleObject(m_pThread->m_hThread, INFINITE);
delete m_pThread;
m_pThread = NULL;
}
} BOOL CDirectoryWatch::StartDirectoryWatch(LPCTSTR lpszDirectory, PFN_NotifyAction pFn_NotifyAction)
{
if(NULL == m_pThread)
{
return FALSE;
} if(NULL == lpszDirectory)
{
return FALSE;
} if(NULL == pFn_NotifyAction)
{
return FALSE;
} if(!PathFileExists(lpszDirectory))
{
TRACE("Error Code : %d\n", GetLastError());
return FALSE;
} if(!PathIsDirectory(lpszDirectory))
{
TRACE("Error Code : %d\n", GetLastError());
return FALSE;
} if( == _tcslen(m_szDirectory))
{
StringCchPrintf(m_szDirectory, _countof(m_szDirectory), _T("%s"), lpszDirectory);
}
else if(CSTR_EQUAL != CompareStringOrdinal(m_szDirectory, -, lpszDirectory, -, TRUE))
{
TRACE("Not Change Directory.\n");
return FALSE;
} if(INVALID_HANDLE_VALUE == m_hFile)
{
m_hFile = CreateFile(lpszDirectory, FILE_LIST_DIRECTORY, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED, NULL);
if(INVALID_HANDLE_VALUE == m_hFile)
{
TRACE("Error Code : %d\n", GetLastError());
return FALSE;
}
} return m_pThread->PostThreadMessage(MSG_STARTWATCH, (WPARAM)m_hFile, (LPARAM)pFn_NotifyAction);
} BOOL CDirectoryWatch::StopDirectoryWatch()
{
if(NULL != m_pThread)
{
return m_pThread->PostThreadMessage(MSG_STOPWATCH, , );
} return FALSE;
} UINT __cdecl CDirectoryWatch::DirectoryWatch(LPVOID lParam)
{
WATCH_PARAMETERS* pParam = (WATCH_PARAMETERS*)lParam;
if(NULL == pParam)
{
return ;
}
HANDLE& hFile = pParam->hFile;
BYTE* pBuffer = pParam->pBuffer;
DWORD dwBufferSize = pParam->dwBufferSize;
OVERLAPPED& ol = pParam->ol;
HANDLE& hEvent = pParam->hEvent;
BOOL& bExit = pParam->bExit;
PFN_NotifyAction pFn_NotifyAction = pParam->pFn_NotifyAction;
DWORD dwBytesReturn = ;
DWORD dwRet = WAIT_FAILED;
DWORD dwOffSet = ;
TCHAR szFile[MAX_PATH] = {};
while(TRUE)
{
if(WAIT_OBJECT_0 != WaitForSingleObject(hEvent, INFINITE))
{
TRACE("Error Code : %d\n", GetLastError());
break;
} if(bExit)
{
break;
} if(!ReadDirectoryChangesW(hFile, pBuffer, dwBufferSize, TRUE,
FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME | FILE_NOTIFY_CHANGE_ATTRIBUTES
| FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE | FILE_NOTIFY_CHANGE_LAST_ACCESS
| FILE_NOTIFY_CHANGE_CREATION | FILE_NOTIFY_CHANGE_SECURITY, &dwBytesReturn, &ol, NULL))
{
TRACE("Error Code : %d\n", GetLastError());
break;
}
if(!GetOverlappedResult(hFile, &ol, &dwBytesReturn, TRUE))
{
TRACE("Error Code : %d\n", GetLastError());
break;
}
FILE_NOTIFY_INFORMATION* pFileNotify = (FILE_NOTIFY_INFORMATION*)pBuffer; do
{
if(pFn_NotifyAction && (WAIT_OBJECT_0 == WaitForSingleObject(hEvent, )))
{
pFn_NotifyAction(pFileNotify->Action, pFileNotify->FileName, (pFileNotify->FileNameLength) / sizeof(WCHAR));
} dwOffSet = pFileNotify->NextEntryOffset;
pFileNotify = (FILE_NOTIFY_INFORMATION*)((BYTE*)pFileNotify + dwOffSet);
} while (dwOffSet);
}
TRACE0("DirectoryWatch Thread Exit ... \n");
return ;
} UINT __cdecl CDirectoryWatch::ThreadProc(LPVOID lParam)
{
WATCH_PARAMETERS* pParam = new WATCH_PARAMETERS; if(NULL == pParam)
{
goto __CLEANUP__;
} BYTE* pBuffer = new BYTE[MAX_BUFFER_SIZE];
if(NULL == pBuffer)
{
goto __CLEANUP__;
}
memset(pBuffer, , MAX_BUFFER_SIZE);
pParam->pBuffer = pBuffer;
pParam->dwBufferSize = MAX_BUFFER_SIZE;
HANDLE hWatchEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if(NULL == hWatchEvent)
{
goto __CLEANUP__;
}
pParam->ol.hEvent = hWatchEvent;
CWinThread* pThread = NULL;
HANDLE hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if(NULL == hEvent)
{
goto __CLEANUP__;
}
pParam->hEvent = hEvent;
MSG msg;
while(GetMessage(&msg, NULL, , ))
{
switch(msg.message)
{
case MSG_STARTWATCH:
{
HANDLE hFile = (HANDLE)(msg.wParam);
PFN_NotifyAction pFn_NotifyAction = (PFN_NotifyAction)(msg.lParam);
if((INVALID_HANDLE_VALUE == hFile) && (NULL == pFn_NotifyAction))
{
break;
}
if(NULL == pThread)
{
pParam->hFile = hFile;
pParam->pFn_NotifyAction = pFn_NotifyAction;
pThread = AfxBeginThread(DirectoryWatch, (LPVOID)pParam, , CREATE_SUSPENDED, NULL);
if(NULL == pThread)
{
goto __CLEANUP__;
}
pThread->m_bAutoDelete = FALSE;
pThread->ResumeThread();
}
SetEvent(hEvent);
}
break; case MSG_STOPWATCH:
{
ResetEvent(hEvent);
}
break; case MSG_EXITTHREAD:
{
SetEvent(hEvent);
pParam->bExit = FALSE; if((NULL != pThread) && (NULL != pThread->m_hThread))
{
WaitForSingleObject(pThread->m_hThread, INFINITE);
delete pThread;
pThread = NULL;
}
goto __CLEANUP__;
} default:
break;
}
TranslateMessage(&msg);
DispatchMessage(&msg);
} __CLEANUP__:
if(NULL != hWatchEvent)
{
CloseHandle(hWatchEvent);
hWatchEvent = NULL;
}
if(NULL != pBuffer)
{
delete[] pBuffer;
pBuffer = NULL;
}
if(NULL != pParam)
{
delete pParam;
pParam = NULL;
}
TRACE0("ThreadProc Thread Exit ...\n");
return ;
}
// 测试代码 #include "stdafx.h" #include "DirectoryWatch.h" void NotifyAction(DWORD dwAction, LPWSTR szFile, DWORD dwLength)
{
switch(dwAction)
{
case FILE_ACTION_ADDED:
wprintf(L"FILE_ACTION_ADDED: \n\t");
break; case FILE_ACTION_REMOVED:
wprintf(L"FILE_ACTION_REMOVED: \n\t");
break; case FILE_ACTION_MODIFIED:
wprintf(L"FILE_ACTION_MODIFIED: \n\t");
break; case FILE_ACTION_RENAMED_OLD_NAME:
wprintf(L"FILE_ACTION_RENAMED_OLD_NAME: \n\t");
break; case FILE_ACTION_RENAMED_NEW_NAME:
wprintf(L"FILE_ACTION_RENAMED_NEW_NAME: \n\t");
break; default:
break;
}
WCHAR szPath[MAX_PATH] = {};
wmemcpy(szPath, szFile, min(dwLength, MAX_PATH));
wprintf(L"%s\n", szPath);
} int _tmain(int argc, TCHAR* argv[], TCHAR* envp[])
{
CDirectoryWatch watch;
wprintf(L"Start Directory Watch ...\n");
watch.StartDirectoryWatch(_T("F:\\11"), NotifyAction);
Sleep( * );
watch.StopDirectoryWatch();
wprintf(L"Stop Directory Watch ...\n"); Sleep( * ); wprintf(L"Start Directory Watch ...\n");
watch.StartDirectoryWatch(_T("F:\\11"), NotifyAction);
Sleep( * );
watch.StopDirectoryWatch();
wprintf(L"Stop Directory Watch ...\n");
Sleep( * );
wprintf(L"Process Exit ...\n");
return ;
}
效果如下图所示：
2011-11-13
[C++]使用ReadDirectoryChangesW API監控檔案系統的改變
[C++]使用ReadDirectoryChangesW API監控檔案系統的改變
在C++中若想要監控檔案系統改變有很多方法，可以用FindFirstChangeNotification取得檔案變更、或是Hook底層的API等方法來實現，這邊使用ReadDirectoryChangesW API來實現，該API使用前必須先加入Kernel32.lib。
並加入Windows.h的標頭檔
#include "Windows.h"
這些步驟做完後在程式中就可以看到ReadDirectoryChangesW API了，其函式原型如下：
BOOL WINAPI ReadDirectoryChangesW(
__in HANDLE hDirectory,
__out LPVOID lpBuffer,
__in DWORD nBufferLength,
__in BOOL bWatchSubtree,
__in DWORD dwNotifyFilter,
__out_opt LPDWORD lpBytesReturned,
__inout_opt LPOVERLAPPED lpOverlapped,
__in_opt LPOVERLAPPED_COMPLETION_ROUTINE lpCompletionRoutine
);
該API必須帶入八個參數，hDirectory帶入的是要監控的目錄Handle、lpBuffer帶入的是用來回傳變動資料的空間、nBufferLength是lpBuffer空間的大小、bWatchSubtree是指定是否偵測子目錄、dwNotifyFilter是指定監控的目錄有哪些動作時需要通知、lpBytesReturned是用來回傳變動資料內含的長度、lpOverlapped可用來在非同步環境下使用重疊IO用、lpCompletionRoutine則是當監控完成或取消時所呼叫的回調函式。
其中dwNotifyFilter的值可設定的有FILE_NOTIFY_CHANGE_FILE_NAME、FILE_NOTIFY_CHANGE_DIR_NAME、FILE_NOTIFY_CHANGE_ATTRIBUTES、FILE_NOTIFY_CHANGE_SIZE、FILE_NOTIFY_CHANGE_LAST_WRITE、FILE_NOTIFY_CHANGE_LAST_ACCESS、FILE_NOTIFY_CHANGE_CREATION、與FILE_NOTIFY_CHANGE_SECURITY，詳細所代表的意義可參閱ReadDirectoryChangesW function。
了解了函式原型後，就可以開始進入實際的使用。剛有提到說在ReadDirectoryChangesW API函式必須要帶入的第一個參數是要監控的目錄Handle，所以我們必須透過CreateFile API取得要監控的目錄Handle，像是下面這樣：
HANDLE hDirectoryHandle = NULL; hDirectoryHandle = ::CreateFileA(
file,
FILE_LIST_DIRECTORY,
FILE_SHARE_READ
| FILE_SHARE_WRITE
| FILE_SHARE_DELETE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS
| FILE_FLAG_OVERLAPPED,
NULL); if(hDirectoryHandle == INVALID_HANDLE_VALUE)
return;
取得監控的目錄Handle後，將其帶入ReadDirectoryChangesw API，順帶帶入像是回傳變動資料的Buffer空間、與要監控的變動類型等必要參數。像是下面這樣：
int nBufferSize = ;
char* buffer = new char[nBufferSize];
DWORD dwBytes = ; memset(buffer, , nBufferSize); if(!::ReadDirectoryChangesW(
hDirectoryHandle,
buffer,
nBufferSize,
bIncludeSubdirectories,
FILE_NOTIFY_CHANGE_LAST_WRITE | FILE_NOTIFY_CHANGE_CREATION | FILE_NOTIFY_CHANGE_FILE_NAME,
&dwBytes,
NULL,
NULL) || GetLastError() == ERROR_INVALID_HANDLE)
{
break;
} if(!dwBytes)
{
printf("Buffer overflow~~\r\n");
}
這邊需注意到的是，若是變動的資料太多，提供的存儲空間不足以存放時，回傳的變動資料長度會是0，此時所有變動資料都會丟失。這樣的情況多半只會出在一瞬間大量的變動，可以增大存儲空間或是減少監控的變動類型，以減少回傳的資料量，避免溢位的發生。
若是運行沒發生問題，變動的資料會存放在當初塞進去的存儲空間，該空間的資料其實是FILE_NOTIFY_INFORMATION structure的型態存在，因此我們可將存儲空間的資料轉換成PFILE_NOTIFY_INFORMATION。裡面的Action是我們所關注的變動類型，FileName是變動的檔案名稱，檔案名稱的部分是沒有結尾符號的，必須要搭配FileNameLength去截取。另外變動的資料有時候不止一筆，因此我們必須在這邊用迴圈搭配NextEntryOffset去重覆運行處理流程，處理所有變動的資料。
PFILE_NOTIFY_INFORMATION record = (PFILE_NOTIFY_INFORMATION)buffer;
DWORD cbOffset = ; do
{
switch (record->Action)
{
case FILE_ACTION_ADDED:
printf("FILE_ACTION_ADDED:");
break;
case FILE_ACTION_REMOVED:
printf("FILE_ACTION_REMOVED:");
break;
case FILE_ACTION_MODIFIED:
printf("FILE_ACTION_MODIFIED:");
break;
case FILE_ACTION_RENAMED_OLD_NAME:
printf("FILE_ACTION_RENAMED_OLD_NAME:");
break; case FILE_ACTION_RENAMED_NEW_NAME:
printf("FILE_ACTION_RENAMED_NEW_NAME:");
break; default:
break;
} char fileBuffer[]; WideCharToMultiByte(CP_ACP, , record->FileName, record->FileNameLength, fileBuffer, record->FileNameLength, NULL, NULL);
printf(fileBuffer);
printf("\r\n"); cbOffset = record->NextEntryOffset;
record = (PFILE_NOTIFY_INFORMATION)((LPBYTE) record + cbOffset);
}while(cbOffset);
這邊示範一個簡易的使用範例，實際使用時最好還是搭配執行緒處理：
// ConsoleApplication10.cpp : Defines the entry point for the console application.
// #include "stdafx.h"
#include "Windows.h" void MonitorDir(char* file, bool bIncludeSubdirectories = false)
{
int nBufferSize = ;
char* buffer = new char[nBufferSize];
HANDLE hDirectoryHandle = NULL; hDirectoryHandle = ::CreateFileA(
file,
FILE_LIST_DIRECTORY,
FILE_SHARE_READ
| FILE_SHARE_WRITE
| FILE_SHARE_DELETE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS
| FILE_FLAG_OVERLAPPED,
NULL); if(hDirectoryHandle == INVALID_HANDLE_VALUE)
return; while()
{
DWORD dwBytes = ; memset(buffer, , nBufferSize); if(!::ReadDirectoryChangesW(
hDirectoryHandle,
buffer,
nBufferSize,
bIncludeSubdirectories,
FILE_NOTIFY_CHANGE_LAST_WRITE | FILE_NOTIFY_CHANGE_CREATION | FILE_NOTIFY_CHANGE_FILE_NAME,
&dwBytes,
NULL,
NULL) || GetLastError() == ERROR_INVALID_HANDLE)
{
break;
} if(!dwBytes)
{
printf("Buffer overflow~~\r\n");
} PFILE_NOTIFY_INFORMATION record = (PFILE_NOTIFY_INFORMATION)buffer;
DWORD cbOffset = ; do
{
switch (record->Action)
{
case FILE_ACTION_ADDED:
printf("FILE_ACTION_ADDED:");
break;
case FILE_ACTION_REMOVED:
printf("FILE_ACTION_REMOVED:");
break;
case FILE_ACTION_MODIFIED:
printf("FILE_ACTION_MODIFIED:");
break;
case FILE_ACTION_RENAMED_OLD_NAME:
printf("FILE_ACTION_RENAMED_OLD_NAME:");
break; case FILE_ACTION_RENAMED_NEW_NAME:
printf("FILE_ACTION_RENAMED_NEW_NAME:");
break; default:
break;
} char fileBuffer[]; WideCharToMultiByte(CP_ACP, , record->FileName, record->FileNameLength, fileBuffer, record->FileNameLength, NULL, NULL);
printf(fileBuffer);
printf("\r\n"); cbOffset = record->NextEntryOffset;
record = (PFILE_NOTIFY_INFORMATION)((LPBYTE) record + cbOffset);
}while(cbOffset);
} delete buffer; if(hDirectoryHandle)
CloseHandle(hDirectoryHandle);
} int _tmain(int argc, _TCHAR* argv[])
{
MonitorDir("C:\\Users\\larry\\Desktop\\新增資料夾");
運行後去對監控的目錄操作~可得到類似如下的結果：
