根据msdn上的讨论,可能是因为一次写的操作包含两次write操作,一次是写内容,一次是写size
http://blogs.msdn.com/b/oldnewthing/archive/2014/05/07/10523172.aspx
下面是网上收集的一个例子
#include <Windows.h> #include <iostream> using namespace std; int _tmain(int argc, _TCHAR* argv[]) { DWORD cbBytes; char file_name[MAX_PATH]; //设置文件名 char file_name2[MAX_PATH]; //设置文件重命名后的名字 char notify[1024]; int count = 0; //文件数量。可能同时拷贝、删除多个文件,可以进行更友好的提示。 TCHAR *dir = _T("E:\\Works\\aaa"); HANDLE dirHandle = CreateFile(dir,GENERIC_READ | GENERIC_WRITE | FILE_LIST_DIRECTORY, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); if(dirHandle == INVALID_HANDLE_VALUE) //若网络重定向或目标文件系统不支持该操作,函数失败,同时调用GetLastError()返回ERROR_INVALID_FUNCTION { cout<<"error"+GetLastError()<<endl; } memset(notify,0,strlen(notify)); FILE_NOTIFY_INFORMATION *pnotify = (FILE_NOTIFY_INFORMATION*)notify; cout<<"start...."<<endl; while(true) { if(ReadDirectoryChangesW(dirHandle,¬ify,1024,TRUE, //FILE_NOTIFY_CHANGE_FILE_NAME | //FILE_NOTIFY_CHANGE_DIR_NAME ////| FILE_NOTIFY_CHANGE_CREATION FILE_NOTIFY_CHANGE_LAST_WRITE, //| FILE_NOTIFY_CHANGE_SIZE, &cbBytes,NULL,NULL)) { //转换文件名为多字节字符串 if(pnotify->FileName) { memset(file_name,0,strlen(file_name)); WideCharToMultiByte(CP_ACP,0,pnotify->FileName,pnotify->FileNameLength/2,file_name,99,NULL,NULL); } //获取重命名的文件名 if(pnotify->NextEntryOffset !=0 && (pnotify->FileNameLength > 0 && pnotify->FileNameLength < MAX_PATH)) { PFILE_NOTIFY_INFORMATION p = (PFILE_NOTIFY_INFORMATION)((char*)pnotify+pnotify->NextEntryOffset); memset(file_name2,0,sizeof(file_name2) ); WideCharToMultiByte(CP_ACP,0,p->FileName,p->FileNameLength/2,file_name2,99,NULL,NULL ); } //设置类型过滤器,监听文件创建、更改、删除、重命名等 switch(pnotify->Action) { case FILE_ACTION_ADDED: count++; cout<<count<<"\t"<<"file add:"<<"\t"<<file_name<<endl; break; case FILE_ACTION_MODIFIED: cout<<"file modified:"<<"\t"<<file_name<<endl; break; case FILE_ACTION_REMOVED: count++; cout<<count<<"\t"<<"file removed:"<<"\t"<<file_name<<endl; break; case FILE_ACTION_RENAMED_OLD_NAME: cout<<"file renamed:"<<"\t"<<file_name<<"->"<<file_name2<<endl; break; default: cout<<"unknow command!"<<endl; } } } CloseHandle(dirHandle); return 0; }