关于ReadDirectoryChangesW多次通知？？？

jamseyang 2010-04-26 08:37:13

我只修改一次文件，为什么下面代码会打印多次呢？？



#include <stdio.h>

#include <Windows.h>

int _tmain(int argc, _TCHAR* argv[])

{







    HANDLE hand = CreateFile(   

        "D:\\Test",              

        FILE_LIST_DIRECTORY, 

        FILE_SHARE_READ|FILE_SHARE_DELETE,

        NULL,

        OPEN_EXISTING,

        FILE_FLAG_BACKUP_SEMANTICS,

        NULL

        );



    char   notify[1024] = {0};   

    FILE_NOTIFY_INFORMATION   *pnotify=(FILE_NOTIFY_INFORMATION   *)notify;   

    DWORD   cbBytes;   

    while(true)   

    {   

        BOOL ret = ReadDirectoryChangesW(hand,

            ¬ify,   

            sizeof(notify),   

            TRUE,   

            FILE_NOTIFY_CHANGE_LAST_WRITE|FILE_NOTIFY_CHANGE_FILE_NAME,

            &cbBytes,   

            NULL,   

            NULL);



        if(ret)   

        {   

            char   AnsiChar[1024] = {0};

            WideCharToMultiByte(CP_ACP,0,pnotify->FileName,pnotify->FileNameLength/2,AnsiChar,1024,NULL,NULL);

            if(FILE_ACTION_MODIFIED   ==   pnotify->Action)   

            {

                printf("%s Modified\n",AnsiChar);//为什么会打印多次???

            }

            else if (FILE_ACTION_ADDED == pnotify->Action)

            {

                printf("%s Add\n",AnsiChar);

            }

            else if (FILE_ACTION_REMOVED == pnotify->Action)

            {

                printf("%s Removed\n",AnsiChar);

            }

        }

    }



    return 0;

}

...全文

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mcaok 2010-04-27

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像word,excel等分块写入的软件当然会多次通知。而且改名，复制，新建都会多出一个Modify通知。

jamseyang 2010-04-27

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还有个问题"C:\Documents and Settings\Administrator\Application Data"为什么CreateFile出错呀????

jamseyang 2010-04-27

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[Quote=引用 2 楼 mcaok 的回复:]
像word,excel等分块写入的软件当然会多次通知。而且改名，复制，新建都会多出一个Modify通知。
[/Quote]
这个我知道,我修改的是txt

尹成 2010-04-26

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改成这样试试：



if(true)   

    {   

        BOOL ret = ReadDirectoryChangesW(hand,

            ¬ify,   

            sizeof(notify),   

            TRUE,   

            FILE_NOTIFY_CHANGE_LAST_WRITE|FILE_NOTIFY_CHANGE_FILE_NAME,

            &cbBytes,   

            NULL,   

            NULL);



        if(ret)   

        {   

            char   AnsiChar[1024] = {0};

            WideCharToMultiByte(CP_ACP,0,pnotify->FileName,pnotify->FileNameLength/2,AnsiChar,1024,NULL,NULL);

            if(FILE_ACTION_MODIFIED   ==   pnotify->Action)   

            {

                printf("%s Modified\n",AnsiChar);//为什么会打印多次???

            }

            else if (FILE_ACTION_ADDED == pnotify->Action)

            {

                printf("%s Add\n",AnsiChar);

            }

            else if (FILE_ACTION_REMOVED == pnotify->Action)

            {

                printf("%s Removed\n",AnsiChar);

            }

        }

    }