了解文件系统观察器
本文关键字:观察 文件系统 了解 | 更新日期: 2023-09-27 18:36:12
我编写一个简单的示例程序,它应该将数据写入文件并在有一些数据时实时读取。我写了这段代码:
using System;
using System.IO;
using System.Reflection;
using System.Threading;
namespace Sample
{
class Program
{
static void Main(string[] args)
{
const string file = "sample.txt";
var thread = new Thread(() =>
{
var r = new Random();
using (var sw = new StreamWriter(new FileStream(file, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite)) {AutoFlush = true})
{
while (true)
{
Thread.Sleep(r.Next(100, 500));
sw.WriteLine(DateTime.Now);
}
}
});
thread.Start();
using (var watcher = new FileSystemWatcher
{
Path = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location),
Filter = file,
NotifyFilter = NotifyFilters.LastWrite
})
{
var mse = new ManualResetEventSlim(false);
watcher.Changed += (sender, eventArgs) =>
mse.Set();
watcher.EnableRaisingEvents = true;
using (var sr = new StreamReader(new FileStream(file, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite)))
{
while (true)
{
mse.Wait();
ProcessData(sr.ReadToEnd());
mse.Reset();
}
}
}
}
private static void ProcessData(string s)
{
Console.WriteLine(s);
}
}
}
但似乎watcher
仅在打开文件时才有效,但在填充信息时不起作用(即使在StreamWriter
上启用了AutoFlush
标志)。数据在磁盘上物理上,但观察程序不会引发事件File changed
。
我只是想避免无限循环,只在写入数据时才处理数据。
如果你不关闭它们,我认为你应该通过将FileStream
和StreamWriter
放在一个using
子句中来处理它们:
string file = "sample.txt";
using (var fs =new FileStream(file, FileMode.Create,
FileAccess.ReadWrite, FileShare.ReadWrite))
using (var sw = new StreamWriter(fs) {AutoFlush = true})
{
..
..
}
在直接关闭或通过释放关闭之前,不会通知文件系统更改已完成。否则,您将被更改的事件淹没。