C＃：使用FileSystemWatcher监视文件的更改 [英] C#: Using FileSystemWatcher to watch for changes to files

问题描述

好的，所以我从如何检查打开的文件是否已更新我应该使用 FileSystemWatcher 用于监视文件的更改。那么现在问题是我是否必须跟踪许多文件，我是否为每个文件创建了一个观察者？此外，一旦文件关闭，我必须以某种方式处理观察者。是否有字典< string，FileSystemWatcher> 存储文件路径和 FileSystemWatcher 的方法？当我打开更多文件时，我添加更多观察者，当我关闭时，适当地处理观察者。有太多的观察者会不会是一件坏事？

Ok, so I learnt from How to check if a open file has been updated that I should use a FileSystemWatcher to watch for changes to files. Then now, the question is if I must keep track of many files, do I create 1 watcher for each file? Also, I must somehow dispose of the watcher once the file is closed. Is having a Dictionary<string, FileSystemWatcher> storing the filepath and the FileSystemWatcher the way to go? as I open more files, I add more watcher and as I close, dispose of the watchers appropriately. Will having too many watchers be a bad thing?

更新

我只是确实

protected void AttachFileMonitor(EditorTabViewModel tab)
{
    string file = tab.FilePath;
    if (!_fsWatchers.ContainsKey(file))
    {
        var watcher = new FileSystemWatcher();
        watcher.Path = Path.GetDirectoryName(file);
        watcher.Filter = Path.GetFileName(file);
        watcher.Changed += (s, e) =>
        {
            string message = "";
            string caption = "";
            MessageBoxButton buttons = MessageBoxButton.YesNo;
            MessageBoxImage image = MessageBoxImage.Question;
            MessageBoxResult defaultResult = MessageBoxResult.Yes;
            MessageBoxResult result = _dialogSvc.GetMessageBox(message, caption, buttons, image, defaultResult);
            if (result == MessageBoxResult.Yes)
            {
                tab.Open(file);
            }
        };
        _fsWatchers.Add(file, watcher);
    }
}
protected void DetachFileMonitor(EditorTabViewModel tab)
{
    if (_fsWatchers.ContainsKey(tab.FilePath)) {
        _fsWatchers.Remove(tab.FilePath);
    }
}

我发现已更改（ ）永远不会被触发...

I found that Changed() never gets triggered ...

推荐答案

如果你为每个目录创建一个观察者就足够了（并且可选地，您可以让观察者监视整个目录树。）然后，您可以使用事件将更改的文件与您感兴趣的文件列表进行比较。

It's enough if you create a watcher for each directory (and optionally, you can have the watcher to monitor a whole directory tree.) You can then use the events to compare the changed files with the list of files you are interested in.

我建议你为观察者制作某种保姆课程，以确保你不会处置活跃的观察者，或创造重复。只是一个提示：）

I would suggest you make some kind of "nanny" class for the watchers to ensure you doesn't dispose active watchers, or create duplicate. Just a tip :)

顺便说一下，是的，有一个限制，你不能创建无限的观察者。在特定的情况下，这可能是一个问题，但很可能，情况并非如此

Btw, yes, there's a limit, you can't create infinite watchers. In specific scenarios that can be a problem, but most likely, that's not the case for you

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