FileSystemWatcher "wrapper" 未触发事件

Question

我已经为 FileSystemWatcher 创建了一个包装器 class，但是我无法触发事件。它们在使用 FileSystemWatcher class 时按预期触发，但不是我的包装器。

知道为什么吗？

public class FolderWatcher
{
    public event FileSystemEventHandler Created;
    public event FileSystemEventHandler Changed;
    private FileSystemWatcher _watcher;

    public FolderWatcher(string watchedFolderPath)
    {
        _watcher = new FileSystemWatcher(watchedFolderPath);
        _watcher.Created += Created;
        _watcher.Changed += Changed;
        _watcher.EnableRaisingEvents = true;
    }
}

class Program
{
    static async Task Main(string[] args)
    {
        string watchedFolder = "/home/user";

        // 1. Custom wrapper for FileSystemWatcher. No events get fired.
        FolderWatcher watcher = new FolderWatcher(watchedFolder);

        // 2. The built in FileSystemWatcher works as expected. Uncomment to test.
        // FileSystemWatcher watcher = new FileSystemWatcher(watchedFolder);
        // watcher.EnableRaisingEvents = true;

        bool createdTriggered = false;
        bool changedTriggered = false;
        bool wait = (changedTriggered == false && createdTriggered == false);

        watcher.Created += (sender, args) => 
        {
            createdTriggered = true;
            Console.WriteLine($"{args.Name} created!");
        };

        watcher.Changed += (sender, args) => 
        {
            changedTriggered = true;
            Console.WriteLine($"{args.Name} changed!");
        };

        Console.WriteLine($"Watching folder {watchedFolder}");

        while (wait)
        {
            await Task.Delay(1);
        }

        Console.WriteLine("Closing application...");
    }
}

为了对此进行测试，我刚刚启动它并在 /home/user 中创建一个新的 file/editing 现有文件。场景 1（在代码中注释）不会触发事件，但场景 2（在代码中注释）会触发事件。我正在努力找出原因。

值得注意的是，我正在松散地关注

Answer 1

与其尝试将文件观察器的事件挂接到您的事件，不如在捕获文件观察器的事件时触发您的事件。

watcher.Changed += (sender, args) => 
{
    if (Changed != null)
        Changed(sender, args);
}

您的活动可供使用您的 class 的人使用。

Answer 2

为了简化 Robert Harvey 的回答，只需将您的构造函数更新为：

    public FolderWatcher(string watchedFolderPath)
    {
        _watcher = new FileSystemWatcher(watchedFolderPath);

        _watcher.Created += (sender, args) =>
        {
            if (this.Created != null)
            {
                this.Created(sender, args);
            }
        };

        _watcher.Changed += (sender, args) =>
        {
            if (this.Changed != null)
            {
                this.Changed(sender, args);
            }
        };

        _watcher.EnableRaisingEvents = true;
    }

FileSystemWatcher "wrapper" 未触发事件

FileSystemWatcher "wrapper" not triggering events

c#

filesystemwatcher