好多时候，我们都需要知道某些目录下的文件什么时候被修改、删除过等，如果能用miniFilter驱动过滤来做的话当然是最好不过了，这是内核级别的，当然也比较复杂。如果只是简单的记录就没必要用驱动过滤级别的来做了，用FileSystemWatcher来做就要简单得多。
FileSystemWatcher组件可以监视文件系统，并在文件系统发生改变时作出反应。FileSystemWatcher 常用于文件系统变更的监控，当被监视的文件夹目录被创建、修改、重命名或删除时，会触发以下事件：
Created: 当新建文件或者文件夹Changed:当文件或者文件夹已经完成修改Renamed:当文件或者文件夹完成重命名Deleted:当文件或者文件夹被删除Error:当变更过程发生错误
下面我们一起来完成一个文件监控实例。
一、实例化FileSystemWatcher类，并注册监听事件
//创建一个FileSystemWatcher，并设置其属性
FileSystemWatcher fileSystemWatcher = new FileSystemWatcher();
//设置监控的路径
fileSystemWatcher.Path = “监控路径”;
//是否监控指定路径中的子目录
fileSystemWatcher.IncludeSubdirectories = true;
//启用
fileSystemWatcher.EnableRaisingEvents = true;
//注册监听事件，Created、Changed、Deleted三个事件传递的参数是一样的，我们就用同一个方法来处理就可以了
fileSystemWatcher.Changed += new FileSystemEventHandler(FileSystemWatcher_EventHandler);
fileSystemWatcher.Created += new FileSystemEventHandler(FileSystemWatcher_EventHandler);
fileSystemWatcher.Deleted += new FileSystemEventHandler(FileSystemWatcher_EventHandler);
fileSystemWatcher.Renamed += new RenamedEventHandler(FileSystemWatcher_Renamed);
fileSystemWatcher.Error += new ErrorEventHandler(FileSystemWatcher_Error);
二、事件处理
FileSystemEventArgs 对象成员有：Name、OldName、ChangeType、FullPath、OldFullPath等，看名就明白是什么了，这里不做过多解释。
//创建一个FileSystemWatcher，并设置其属性
FileSystemWatcher fileSystemWatcher = new FileSystemWatcher();
//设置监控的路径
fileSystemWatcher.Path = “监控路径”;
//是否监控指定路径中的子目录
fileSystemWatcher.IncludeSubdirectories = true;
//启用
fileSystemWatcher.EnableRaisingEvents = true;
//Created、Changed、Deleted三个事件的处理方法
private static void FileSystemWatcher_EventHandler(object sender, FileSystemEventArgs e)
{
Invoke(new Action(new Action(() =>
{
Console.WriteLine(e.Name+e.FullPath);
})));
}
//重命名事件的处理方法
private void FileSystemWatcher_Renamed(object sender, RenamedEventArgs e)
{
Invoke(new Action(new Action(() =>
{
Console.WriteLine(e.OldName+e.Name+e.FullPath);
})));
}
//错误事件的处理方法
private void FileSystemWatcher_Error(object sender, ErrorEventArgs e)
{
Invoke(new Action(new Action(() =>
{
Console.WriteLine(e.ToString()));
})));
}
这里需要注意一个问题：因为FileSystemWatcher类本身就是一个多线程的控件，在实例化一个FileSystemWatcher时就自动创建了一个线程，在事件处理的方法中需要使用委托的方式封送到主线程中处理。
//声明传递文件Created、Changed、Deleted对象和委托，用于文件增加、删除、修改时更新UI界面
private delegate void setLogDelegate(FileSystemEventArgs e);
三、展示监控记录
监控的记录可以保存到文件和数据库中，这里就增加一个listView来展示就好了
代码：
using System;using System.Collections.Generic;using ponentModel;using System.Data;using System.Drawing;using System.IO;using System.Linq;using System.Runtime.InteropServices;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace FileWatcher{public partial class Form1 : Form{private delegate void renameDelegate(RenamedEventArgs e); //声明传递RenamedEventArgs对象和委托，用于文件Renamed时更新UI界面private delegate void setLogDelegate(FileSystemEventArgs e); //声明传递文件Created、Changed、Deleted对象和委托，用于文件增加、删除、修改时更新UI界面private FileSystemWatcher fileSystemWatcher = new FileSystemWatcher();private ColumnHeader chTime = new ColumnHeader();private ColumnHeader chEvent = new ColumnHeader();private ColumnHeader chFile = new ColumnHeader();private ColumnHeader chPath = new ColumnHeader();public Form1(){InitializeComponent();chTime.TextAlign = HorizontalAlignment.Center;chTime.Width = 130;chTime.Text = "时间";this.listViewInfo.Columns.Add(chTime);chEvent.TextAlign = HorizontalAlignment.Center;chEvent.Width = 80;chEvent.Text = "事件";this.listViewInfo.Columns.Add(chEvent);chFile.Width = 270;chFile.Text = "文件";this.listViewInfo.Columns.Add(chFile);chPath.Width = this.listViewInfo.Width - chTime.Width - chEvent.Width - chFile.Width - 21;chPath.Text = "位置";this.listViewInfo.Columns.Add(chPath);ColumnHeader chEnd = new ColumnHeader();chEnd.Width = 17;chEnd.Text = "";this.listViewInfo.Columns.Add(chEnd);this.listViewInfo.View = View.Details;this.listViewInfo.GridLines = true;fileSystemWatcher.Changed += new FileSystemEventHandler(FileSystemWatcher_EventHandler);fileSystemWatcher.Created += new FileSystemEventHandler(FileSystemWatcher_EventHandler);fileSystemWatcher.Deleted += new FileSystemEventHandler(FileSystemWatcher_EventHandler);fileSystemWatcher.Renamed += new RenamedEventHandler(FileSystemWatcher_Renamed);fileSystemWatcher.Error += new ErrorEventHandler(FileSystemWatcher_Error);fileSystemWatcher.IncludeSubdirectories = true;fileSystemWatcher.EnableRaisingEvents = true;}#region 文件增加、删除、修改时被调用的处理方法private void FileSystemWatcher_EventHandler(object sender, FileSystemEventArgs e){if (listViewInfo.InvokeRequired) //判断是否跨线程{listViewInfo.Invoke(new setLogDelegate(SetLog), new object[] { e });//使用委托将方法封送到UI主线程处理}}private void SetLog(FileSystemEventArgs e){string strLog = "";switch (e.ChangeType.ToString()){case "Created":strLog = "文件创建";break;case "Changed":strLog = "文件修改";break;case "Deleted":strLog = "文件删除";break;default:strLog = e.ChangeType.ToString();break;}ListViewItem lvi = new ListViewItem();lvi.Text = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"); lvi.SubItems.Add(strLog); lvi.SubItems.Add(e.Name); lvi.SubItems.Add(e.FullPath.Replace(e.Name,"")); listViewInfo.Items.Add(lvi);}#endregion#region 重命名方法private void FileSystemWatcher_Renamed(object sender, RenamedEventArgs e){if (listViewInfo.InvokeRequired){listViewInfo.Invoke(new renameDelegate(SetRenamedLog), new object[]{e});}}private void SetRenamedLog(RenamedEventArgs e){//listViewInfo.Items.Add(string.Format("重命名：{0} 被换名为：{1}， {2}", e.OldName, e.Name, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")));ListViewItem lvi = new ListViewItem();lvi.Text = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");lvi.SubItems.Add("文件重命名");lvi.SubItems.Add(e.OldName + "被换名为：" + e.Name);lvi.SubItems.Add(e.FullPath.Replace(e.Name, ""));listViewInfo.Items.Add(lvi);}#endregion#region 错误事件的方法private void FileSystemWatcher_Error(object sender, ErrorEventArgs e){if (listViewInfo.InvokeRequired) //判断是否跨线程{//使用委托处理Invoke(new Action(new Action(() =>{listViewInfo.Items.Add(string.Format("文件出错：{0}， {1}", e.ToString(), DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")));})));}}#endregion}}
完整例子下载
