c# – FileSystemWatcher有一个奇怪的行为

我想监视PBX的日志文件以进行更改.我用FileSystemWatcher制作了一个小程序.

现在它变得很奇怪：当我启动程序时,FileSystemWatcher永远不会触发Changed-Event.尽管事实上日志文件确实发生了变化.但是当我在Windows资源管理器中打开日志文件所在的目录时,程序按预期工作.但只要资源管理器窗口保持打开状态……什么……？

操作系统：Windows Server 2008 R2

编辑：对不起,这是代码：

class Program
{
    static void Main(string[] args)
    {
        new LogFileWatcher(@"C:\PBX\Dial.log");
        System.Console.Read();
    }
}

public class LogFileWatcher
{
    public string LogFilePath { get; private set; }

    private DateTime _lastLogFileWriteTime;

    public LogFileWatcher(string path)
    {
        LogFilePath = path;
        var directoryName = Path.GetDirectoryName(LogFilePath);
        var fileName = Path.GetFileName(LogFilePath);

        var fsw = new FileSystemWatcher { Path = directoryName,Filter = fileName };
        fsw.Changed += fsw_Changed;
        fsw.EnableRaisingEvents = true;
    }

    private void fsw_Changed(object sender,FileSystemEventArgs e)
    {
        // Get and fix the last write time of the log file
        var fixLastWriteTime = File.GetLastWriteTime(LogFilePath);

        // Don't do anything when file didn't change since last time
        if (fixLastWriteTime == _lastLogFileWriteTime) return;

        Console.WriteLine("File changed on: {0} - ID:{1}",DateTime.Now.ToLongTimeString(),Guid.NewGuid());

        // Save last write time of the log file
        _lastLogFileWriteTime = fixLastWriteTime;
    }
}

EDIT2：也许这很重要：PBX Windows服务正在使用日志文件！我可以用记事本打开它.

解决方法

阅读 http://blogs.msdn.com/b/alejacma/archive/2011/03/23/filesystemwatcher-class-does-not-fire-change-events-when-notifyfilters-size-is-used.aspx以获得解释.也许你的情况是一样的.在文件句柄关闭之前,不会触发FW Changed事件.因此,在WindowsService关闭文件之前,您几乎陷入困境.