我使用。net 3.5,试图递归删除目录使用:

Directory.Delete(myPath, true);

我的理解是,如果文件正在使用或存在权限问题,这应该抛出,但否则它应该删除目录及其所有内容。

然而,我偶尔会遇到这样的情况:

System.IO.IOException: The directory is not empty.
    at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
    at System.IO.Directory.DeleteHelper(String fullPath, String userPath, Boolean recursive)
    at System.IO.Directory.Delete(String fullPath, String userPath, Boolean recursive)
    ...

我并不惊讶于这个方法有时会抛出错误,但我惊讶于当递归为真时得到这个特定的消息。(我知道目录不是空的。)

是否有一个原因,我将看到这个而不是AccessViolationException?


当前回答

上面的答案对我都没用。似乎我自己的应用程序在目标目录上使用DirectoryInfo导致它保持锁定。

强制垃圾收集似乎解决了这个问题,但不是马上就能解决的。在需要的地方尝试删除几次。

注意目录。存在,因为它可以在异常后消失。我不知道为什么我的删除被延迟了(Windows 7 SP1)

        for (int attempts = 0; attempts < 10; attempts++)
        {
            try
            {
                if (Directory.Exists(folder))
                {
                    Directory.Delete(folder, true);
                }
                return;
            }
            catch (IOException e)
            {
                GC.Collect();
                Thread.Sleep(1000);
            }
        }

        throw new Exception("Failed to remove folder.");

其他回答

不删除文件的递归目录删除当然是意外的。我的解决办法是:

public class IOUtils
{
    public static void DeleteDirectory(string directory)
    {
        Directory.GetFiles(directory, "*", SearchOption.AllDirectories).ForEach(File.Delete);
        Directory.Delete(directory, true);
    }
}

我经历过这样做有帮助的案例,但一般来说,Directory。Delete在递归删除时删除目录中的文件,如msdn中所述。

作为Windows资源管理器的用户,我偶尔也会遇到这种不正常的行为:有时我无法删除文件夹(它认为荒谬的消息是“拒绝访问”),但当我向下钻取并删除较低的项目时,我也可以删除上面的项目。所以我猜上面的代码处理的是操作系统异常——而不是基类库问题。

我已经解决了这个千年技术(你可以离开线程。睡在自己的捕捉)

bool deleted = false;
        do
        {
            try
            {
                Directory.Delete(rutaFinal, true);                    
                deleted = true;
            }
            catch (Exception e)
            {
                string mensaje = e.Message;
                if( mensaje == "The directory is not empty.")
                Thread.Sleep(50);
            }
        } while (deleted == false);

上面的答案对我都没用。似乎我自己的应用程序在目标目录上使用DirectoryInfo导致它保持锁定。

强制垃圾收集似乎解决了这个问题,但不是马上就能解决的。在需要的地方尝试删除几次。

注意目录。存在,因为它可以在异常后消失。我不知道为什么我的删除被延迟了(Windows 7 SP1)

        for (int attempts = 0; attempts < 10; attempts++)
        {
            try
            {
                if (Directory.Exists(folder))
                {
                    Directory.Delete(folder, true);
                }
                return;
            }
            catch (IOException e)
            {
                GC.Collect();
                Thread.Sleep(1000);
            }
        }

        throw new Exception("Failed to remove folder.");

这是因为FileChangesNotifications。

它发生在ASP。NET 2.0。当你删除应用程序中的某个文件夹时,它会重新启动。你可以自己看,用 ASP。NET运行状况监视。

只需将这段代码添加到你的web.config/configuration/system.web:

<healthMonitoring enabled="true">
  <rules>
    <add name="MyAppLogEvents" eventName="Application Lifetime Events" provider="EventLogProvider" profile="Critical"/>
  </rules>
</healthMonitoring>

之后,检查Windows Log ->应用程序。 发生了什么:

删除文件夹时,如果有子文件夹,delete (path, true)会先删除子文件夹。这足以让FileChangesMonitor知道删除和关闭你的应用程序。同时你的主目录还没有删除。这是来自日志的事件:

Delete()没有完成它的工作,因为应用程序正在关闭,它引发了一个异常:

当你正在删除的文件夹中没有任何子文件夹时,Delete()只是删除所有文件和该文件夹,app也会重新启动,但你不会得到任何异常,因为app重新启动不会中断任何事情。但是,你仍然会失去所有进程中的会话,应用程序在重新启动时不响应请求,等等。

现在该做什么?

There are some workarounds and tweaks to disable this behaviour, Directory Junction, Turning Off FCN with Registry, Stopping FileChangesMonitor using Reflection (since there is no exposed method), but they all don't seem to be right, because FCN is there for a reason. It is looking after structure of your app, which is not structure of your data. Short answer is: place folders you want to delete outside of your app. FileChangesMonitor will get no notifications and your app will not be restarted every time. You will get no exceptions. To get them visible from the web there are two ways:

创建一个控制器来处理传入调用,然后通过从应用程序外部(wwwroot外部)的文件夹读取文件返回。 如果你的项目很大,性能是最重要的,那就单独设置一个小型快速的web服务器来提供静态内容。因此,您将把他的具体工作留给IIS。它可以在同一台机器上(Windows的mongoose),也可以在另一台机器上(Linux的nginx)。好消息是你不需要支付额外的微软许可证来在linux上设置静态内容服务器。

希望这能有所帮助。

在继续之前,检查一下你能控制的以下原因:

该文件夹是否设置为您的进程的当前目录?如果是,请先将其更改为其他内容。 您是否从该文件夹中打开了文件(或加载了DLL) ?(并且忘记关闭/卸载它)

否则,请检查以下不在你控制范围内的合理原因:

该文件夹中有标记为只读的文件。 您没有删除其中一些文件的权限。 文件或子文件夹在资源管理器或其他应用程序中打开。

如果是上述任何一个问题,在尝试改进删除代码之前,您应该了解为什么会发生这种情况。你的应用程序是否应该删除只读或不可访问的文件?是谁给它们做的标记,为什么?

一旦排除了上述原因,仍然存在虚假失败的可能性。如果任何人持有任何被删除的文件或文件夹的句柄,删除将失败,并且有人可能会枚举文件夹或读取其文件的原因有很多:

搜索索引器 要 备份软件

处理虚假失败的一般方法是尝试多次,在尝试之间暂停。显然,您不希望一直尝试下去,因此应该在一定次数的尝试后放弃,并抛出异常或忽略错误。是这样的:

private static void DeleteRecursivelyWithMagicDust(string destinationDir) {
    const int magicDust = 10;
    for (var gnomes = 1; gnomes <= magicDust; gnomes++) {
        try {
            Directory.Delete(destinationDir, true);
        } catch (DirectoryNotFoundException) {
            return;  // good!
        } catch (IOException) { // System.IO.IOException: The directory is not empty
            System.Diagnostics.Debug.WriteLine("Gnomes prevent deletion of {0}! Applying magic dust, attempt #{1}.", destinationDir, gnomes);

            // see http://stackoverflow.com/questions/329355/cannot-delete-directory-with-directory-deletepath-true for more magic
            Thread.Sleep(50);
            continue;
        }
        return;
    }
    // depending on your use case, consider throwing an exception here
}

在我看来,像这样的帮助器应该用于所有的删除,因为虚假的失败总是可能的。然而,你应该根据你的用例调整这些代码,而不是盲目地复制它。

我的应用程序生成的内部数据文件夹,位于%LocalAppData%下,所以我的分析如下:

The folder is controlled solely by my application, and the user has no valid reason to go and mark things as read-only or inaccessible inside that folder, so I don't try to handle that case. There's no valuable user-created stuff in there, so there's no risk of forcefully deleting something by mistake. Being an internal data folder, I don't expect it to be open in explorer, at least I don't feel the need to specifically handle the case (i.e. I'm fine handling that case via support). If all attempts fail, I choose to ignore the error. Worst case, the app fails to unpack some newer resources, crashes and prompts the user to contact support, which is acceptable to me as long as it does not happen often. Or, if the app does not crash, it will leave some old data behind, which again is acceptable to me. I choose to limit retries to 500ms (50 * 10). This is an arbitrary threshold which works in practice; I wanted the threshold to be short enough so that users wouldn't kill the app, thinking that it has stopped responding. On the other hand, half a second is plenty of time for the offender to finish processing my folder. Judging from other SO answers which sometimes find even Sleep(0) to be acceptable, very few users will ever experience more than a single retry. I retry every 50ms, which is another arbitrary number. I feel that if a file is being processed (indexed, checked) when I try to delete it, 50ms is about the right time to expect the processing to be completed in my case. Also, 50ms is small enough to not result in a noticeable slowdown; again, Sleep(0) seems to be enough in many cases, so we don't want to delay too much. The code retries on any IO exceptions. I don't normally expect any exceptions accessing %LocalAppData%, so I chose simplicity and accepted the risk of a 500ms delay in case a legitimate exception happens. I also didn't want to figure out a way to detect the exact exception that I want to retry on.