编辑

Question

我正试图找出为什么FileSystemWatcher在本地运行的原因，但是当我将其部署到Azure Webapp时却无法运行。

我已验证文件是在webapp文件夹中创建的，但创建文件时看守者似乎未触发。 Azure日志或应用程序日志中没有相关的错误/警告消息。我创建了一个示例应用进行调查，在那里我看到了相同的问题。

public sealed class TestController : Controller
{
    private static readonly ILog _log = LogManager.GetLogger(typeof(TestController));
    private static readonly string _folder = ConfigurationManager.AppSettings["BasePath"];
    private static FileSystemWatcher _watcher;

    [HttpGet, Route("start-monitoring")]
    public ActionResult StartMonitoring()
    {
        if (_watcher != null)
            return new HttpStatusCodeResult(HttpStatusCode.OK);

        _watcher = new FileSystemWatcher(_folder, "*.*") { EnableRaisingEvents = true };

        _watcher.Created += (sender, args) =>
            _log.Debug($"YAY!!! Watcher triggered, new file found `{args.FullPath}`");

        _log.Debug($"Watcher started for folder `{_folder}`");
        return new HttpStatusCodeResult(HttpStatusCode.Created);
    }

    [HttpGet, Route("create-file/{filename}")]
    public async Task<ActionResult> CreateFileAsync(string filename)
    {
        string fullFilename = $"{_folder}\\{filename}.txt";
        using (var writer = new StreamWriter(fullFilename))
        {
            await writer.WriteAsync("Some content").ConfigureAwait(false);
        }

        _log.Debug($"Created file `{fullFilename}`");
        return new HttpStatusCodeResult(HttpStatusCode.OK);
    }
}

本地

使用上面的代码，当我转到http://localhost:23481/start-monitoring时，这将创建监视FileSystemWatcher文件夹的C:\test。

然后，当我转到http://localhost:23481/create-file/blahblah时，将在文件夹blahblah.txt中创建一个名为C:\test的文件。日志文件显示正在创建的文件，以及FSW触发器，表明已注意到有新文件出现。

2019-08-15T10:37:54.705Z    DEBUG     TestProject.TestController
Watcher started for folder `C:\test`

2019-08-15T10:38:02.399Z    DEBUG     TestProject.TestController
Created file `C:\test\blahblah.txt`

2019-08-15T10:38:02.400Z    DEBUG     TestProject.TestController
YAY!!! Watcher triggered, new file found `C:\test\blahblah.txt`

2019-08-15T10:38:06.137Z    DEBUG     TestProject.TestController
Created file `C:\test\another.txt`

2019-08-15T10:38:06.141Z    DEBUG     TestProject.TestController
YAY!!! Watcher triggered, new file found `C:\test\another.txt`

天蓝色

我将相同的代码部署到Azure，唯一的区别是配置中的基本路径。日志显示FileSystemWatcher已正确创建，以监视Azure webapp文件系统上的D:\home\site\wwwroot\test文件夹。

然后，当我转到https://xxx.azurewebsites.net/create-file/blahblah时，将在文件夹blahblah.txt中创建一个名为D:\home\site\wwwroot\test的文件。日志文件显示正在创建的文件，但不显示在创建时触发的FSW：

2019-08-15T10:43:01.681Z    DEBUG     TestProject.TestController
Watcher started for folder `D:\home\site\wwwroot\test`

2019-08-15T10:43:27.010Z    DEBUG     TestProject.TestController
Created file `D:\home\site\wwwroot\test\blahblah.txt`

2019-08-15T10:43:33.834Z    DEBUG     TestProject.TestController
Created file `D:\home\site\wwwroot\test\another.txt`

我也尝试过手动在文件夹中创建文件，但这仍然不会触发！！！日志条目。 FileSystemWatcher不会在Azure中触发是一个已知问题，还是我错过了某些事情？

编辑

我已将处理程序分配给FileSystemWatcher支持的所有事件，即已更改/已创建/已删除/已处置/错误/重命名，并且在Azure中对我唯一触发的事件是Changed。我想我必须做某种黑客来监视Changed事件，我可能可以假设文件是否存在是“ Created”事件，否则是“ Deleted”事件。

Answer 1

我更改了代码以侦听FileSystemWatcher支持的所有事件。我发现在Azure上触发的唯一事件是Changed事件。没有其他事件被调用。我找不到关于此的任何文档，所以可能是错误，也可能是设计的，谁知道。

我现在使用的修复程序在下面，基本上是在Changed事件上，我检查文件是否存在，如果确实存在，我认为这是“文件创建事件”，否则是“文件删除事件”。

[HttpGet, Route("start-monitoring")]
public ActionResult StartMonitoring()
{
    if (_watcher != null)
        return new HttpStatusCodeResult(HttpStatusCode.OK);

    _watcher = new FileSystemWatcher(_folder, "*.*") { EnableRaisingEvents = true };

    //none of these events are triggered in Azure
    _watcher.Created += (sender, args) =>
        _log.Debug($"Watcher triggered `Created`, `{args.FullPath}`");
    _watcher.Deleted += (sender, args) =>
        _log.Debug($"Watcher triggered `Deleted`, `{args.FullPath}`");
    _watcher.Renamed += (sender, args) =>
        _log.Debug($"Watcher triggered `Renamed`, `{args.OldFullPath}` to `{args.FullPath}`");
    _watcher.Error += (sender, args) =>
        _log.Debug($"Watcher triggered `Error`, `{args.GetException().ToString()}`");
    _watcher.Disposed += (sender, args) =>
        _log.Debug($"Watcher triggered `Disposed`");

    //Changed is the only event that gets triggered in Azure
    _watcher.Changed += (sender, args) =>
    {
        if (System.IO.File.Exists(args.FullPath))
            _log.Debug($"Watcher triggered `Changed (created)`, `{args.FullPath}`");
        else
            _log.Debug($"Watcher triggered `Changed (deleted)`, `{args.FullPath}`");
    };

    _log.Debug($"Watcher started for folder `{_folder}`");

    return new HttpStatusCodeResult(HttpStatusCode.Created);
}

这现在对我来说似乎很好：

2019-08-16T08:54:37.419Z    DEBUG     TestProject.TestController
Watcher started for folder `C:\test`

2019-08-16T08:55:16.625Z    DEBUG     TestProject.TestController
Created file `C:\test\moo.txt`

2019-08-16T08:55:16.634Z    DEBUG     TestProject.TestController
Watcher triggered `Changed (created)`, `C:\test\moo.txt`

2019-08-16T08:55:50.096Z    DEBUG     TestProject.TestController
Created file `C:\test\poop.txt`

2019-08-16T08:55:50.101Z    DEBUG     TestProject.TestController
Watcher triggered `Changed (created)`, `C:\test\poop.txt`

FileSystemWatcher不会在Azure中触发

本地

天蓝色

编辑

1 个答案: