如何使用计时器监控文件大小的变化? [英] How to monitor file size changes using a timer?

问题描述

private void MonitorFileForChanges()
{
    Timer timerFileMonitor = new Timer();
    timerFileMonitor.Interval = 10000;
    timerFileMonitor.Tick += timerFileMonitor_Tick;
    timerFileMonitor.Start();
}

void timerFileMonitor_Tick(object sender, EventArgs e)
{
    var directory = new DirectoryInfo(userVideosDirectory);
    var myFile = directory.GetFiles()
     .OrderByDescending(f => f.LastWriteTime)
     .First();
    long oldFileSize = 0;
}

我的问题是如何检查 Tick 事件中的文件大小变化?当没有更多变化时，停止计时器.

My problem is how to check for the file size changes in the Tick event ? And when there is no more changes stop the timer.

尝试使用 FileSystemWather:

Tried to use FileSystemWather:

private void WatchDirectory()
        {
            FileSystemWatcher watcher = new FileSystemWatcher();
            watcher.Path = userVideosDirectory;
            watcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.Size;
            watcher.Filter = "*.mp4";
            watcher.Changed += new FileSystemEventHandler(OnChanged);
            watcher.EnableRaisingEvents = true;
        }

        private void OnChanged(object source, FileSystemEventArgs e)
        {
            if (e.ChangeType == WatcherChangeTypes.Changed)
            {
                var info = new FileInfo(e.FullPath);
                var theSize = info.Length;
                label2.BeginInvoke((Action)(() =>
                {
                    label2.Text = theSize.ToString();
                }));
            }

            dirchanged = true;
        }

这是有效的，但我如何检查最后一次大小更改我的意思是如何在 5 或 10 秒后再次检查它以查看是否有另一个更改，如果没有则停止事件?

This is working but how do i check the last size change i mean how do i check it again after 5 or 10 seconds to see if there was another change and if not then stop the event ?

我的意思是没有像这样完成的事件.

I mean there is no completed event like.

推荐答案

首先，如果你没有充分的理由——不要使用定时器.在大多数情况下，这是一种不好的做法.考虑使用 FileSystemWatcher 代替.

First of all, if you do not have a strong reason - do not use timer. It's a bad practice in most cases. Consider using FileSystemWatcher instead.

关于文件大小 - 为此使用 FileInfo 类.

Regarding the file size - use FileInfo class for that.

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