FindFirstChangeNotification函数创建一个更改通知句柄并设置初始更改通知过滤条件. 当一个在指定目录或子目录下发生的更改符合过滤条件时，等待通知句柄则成功。
该函数原型为：
HANDLE FindFirstChangeNotification(
LPCTSTR lpPathName, //目录名
BOOL bWatchSubtree, // 监视选项
DWORD dwNotifyFilter // 过滤条件
);
当下列情况之一发生时，WaitForMultipleObjects函数返回
1.一个或者全部指定的对象在信号状态(signaled state)
2.到达超时间隔
例程如下:
DWORD dwWaitStatus;
HANDLE dwChangeHandles[2];
//监视C:/Windows目录下的文件创建和删除
dwChangeHandles[0] = FindFirstChangeNotification(
"C://WINDOWS", // directory to watch
FALSE, // do not watch the subtree
FILE_NOTIFY_CHANGE_FILE_NAME);// watch file name changes
if (dwChangeHandles[0] == INVALID_HANDLE_VALUE)
ExitProcess(GetLastError());
//监视C:/下子目录树的文件创建和删除
dwChangeHandles[1] = FindFirstChangeNotification(
"C://", // directory to watch
TRUE, // watch the subtree
FILE_NOTIFY_CHANGE_DIR_NAME);// watch dir. name changes
if (dwChangeHandles[1] == INVALID_HANDLE_VALUE)
ExitProcess(GetLastError());
// Change notification is set. Now wait on both notification
// handles and refresh accordingly
while (TRUE)
{
// Wait for notification
dwWaitStatus = WaitForMultipleObjects(2, dwChangeHandles,FALSE, INFINITE);
switch (dwWaitStatus)
{
case WAIT_OBJECT_0:
//在C:/WINDOWS目录中创建或删除文件
//刷新该目录及重启更改通知(change notification)
AfxMessageBox("RefreshDirectory");
if ( FindNextChangeNotification(dwChangeHandles[0])== FALSE)
ExitProcess(GetLastError());
break;
case WAIT_OBJECT_0 1:
//在C:/WINDOWS目录中创建或删除文件 。
//刷新该目录树及重启更改通知(change notification)
AfxMessageBox("RefreshTree");
if (FindNextChangeNotification(dwChangeHandles[1])== FALSE)
ExitProcess(GetLastError());
break;
default:
ExitProcess(GetLastError());
}
}
该函数原型为：
HANDLE FindFirstChangeNotification(
LPCTSTR lpPathName, //目录名
BOOL bWatchSubtree, // 监视选项
DWORD dwNotifyFilter // 过滤条件
);
当下列情况之一发生时，WaitForMultipleObjects函数返回
1.一个或者全部指定的对象在信号状态(signaled state)
2.到达超时间隔
例程如下:
DWORD dwWaitStatus;
HANDLE dwChangeHandles[2];
//监视C:/Windows目录下的文件创建和删除
dwChangeHandles[0] = FindFirstChangeNotification(
"C://WINDOWS", // directory to watch
FALSE, // do not watch the subtree
FILE_NOTIFY_CHANGE_FILE_NAME);// watch file name changes
if (dwChangeHandles[0] == INVALID_HANDLE_VALUE)
ExitProcess(GetLastError());
//监视C:/下子目录树的文件创建和删除
dwChangeHandles[1] = FindFirstChangeNotification(
"C://", // directory to watch
TRUE, // watch the subtree
FILE_NOTIFY_CHANGE_DIR_NAME);// watch dir. name changes
if (dwChangeHandles[1] == INVALID_HANDLE_VALUE)
ExitProcess(GetLastError());
// Change notification is set. Now wait on both notification
// handles and refresh accordingly
while (TRUE)
{
// Wait for notification
dwWaitStatus = WaitForMultipleObjects(2, dwChangeHandles,FALSE, INFINITE);
switch (dwWaitStatus)
{
case WAIT_OBJECT_0:
//在C:/WINDOWS目录中创建或删除文件
//刷新该目录及重启更改通知(change notification)
AfxMessageBox("RefreshDirectory");
if ( FindNextChangeNotification(dwChangeHandles[0])== FALSE)
ExitProcess(GetLastError());
break;
case WAIT_OBJECT_0 1:
//在C:/WINDOWS目录中创建或删除文件 。
//刷新该目录树及重启更改通知(change notification)
AfxMessageBox("RefreshTree");
if (FindNextChangeNotification(dwChangeHandles[1])== FALSE)
ExitProcess(GetLastError());
break;
default:
ExitProcess(GetLastError());
}
}
