C# FileSystemWatcher监听文件事件
现有一个需求如下:监控某个目录中的文件修改,创建,删除等信息,并记录下来.
这里用到FileSystemWatcher类.由于考虑到文件的写入量会很频率,所以考虑先将监听到的消息记录到内存中。
监听部分的代码如下:
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.IO; using System.Linq; using System.Text; using System.Windows.Forms; namespace FileEventListener { public partial class FSWControl : Form { static int count = 0; static FileSystemWatcher watcher = new FileSystemWatcher(); static int eventCount = 0; //static List<string> files = new List<string>(); public FSWControl() { InitializeComponent(); WatcherStrat(@"D:\test\", "*.tr", true, true); } /// <summary> /// 初始化监听 /// </summary> /// <param name="StrWarcherPath">需要监听的目录</param> /// <param name="FilterType">需要监听的文件类型(筛选器字符串)</param> /// <param name="IsEnableRaising">是否启用监听</param> /// <param name="IsInclude">是否监听子目录</param> private static void WatcherStrat(string StrWarcherPath, string FilterType, bool IsEnableRaising, bool IsInclude) { //初始化监听 watcher.BeginInit(); //设置监听文件类型 watcher.Filter = FilterType; //设置是否监听子目录 watcher.IncludeSubdirectories = IsInclude; //设置是否启用监听? watcher.EnableRaisingEvents = IsEnableRaising; //设置需要监听的更改类型(如:文件或者文件夹的属性,文件或者文件夹的创建时间;NotifyFilters枚举的内容) watcher.NotifyFilter = NotifyFilters.Attributes | NotifyFilters.CreationTime | NotifyFilters.DirectoryName | NotifyFilters.FileName | NotifyFilters.LastAccess | NotifyFilters.LastWrite | NotifyFilters.Security | NotifyFilters.Size; //设置监听的路径 watcher.Path = StrWarcherPath; //注册创建文件或目录时的监听事件 //watcher.Created += new FileSystemEventHandler(watch_created); //注册当指定目录的文件或者目录发生改变的时候的监听事件 watcher.Changed += new FileSystemEventHandler(watch_changed); //注册当删除目录的文件或者目录的时候的监听事件 watcher.Deleted += new FileSystemEventHandler(watch_deleted); //当指定目录的文件或者目录发生重命名的时候的监听事件 watcher.Renamed += new RenamedEventHandler(watch_renamed); //结束初始化 watcher.EndInit(); } /// <summary> /// 创建文件或者目录时的监听事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private static void watch_created(object sender, FileSystemEventArgs e) { //事件内容 output("create:" + e.FullPath); } /// <summary> /// 当指定目录的文件或者目录发生改变的时候的监听事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private static void watch_changed(object sender, FileSystemEventArgs e) { //事件内容 //事件内容 output("change:" + e.FullPath); } /// <summary> /// 当删除目录的文件或者目录的时候的监听事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private static void watch_deleted(object sender, FileSystemEventArgs e) { //事件内容 output("del:" + e.FullPath); } /// <summary> /// 当指定目录的文件或者目录发生重命名的时候的事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private static void watch_renamed(object sender, RenamedEventArgs e) { //事件内容 output("rename:" + e.FullPath); } /// <summary> /// 启动或者停止监听 /// </summary> /// <param name="IsEnableRaising">True:启用监听,False:关闭监听</param> private void WatchStartOrSopt(bool IsEnableRaising) { watcher.EnableRaisingEvents = IsEnableRaising; } private static void output(string text) { //FileStream fs = new FileStream("D:\\listen.txt", FileMode.Append); //StreamWriter sw = new StreamWriter(fs, Encoding.Default); //sw.WriteLine(text); //sw.Close(); //fs.Close(); //files.Add(text); eventCount++; } private void button1_Click(object sender, EventArgs e) { string name = count.ToString() + "_" + eventCount.ToString(); FileStream fs = new FileStream("D:\\listen_" + name + ".txt", FileMode.Append); StreamWriter sw = new StreamWriter(fs, Encoding.Default); //foreach (string text in files) //{ // sw.WriteLine(text); //} sw.WriteLine("共收到事件:" + eventCount.ToString()); //files.Clear(); eventCount = 0; sw.Close(); fs.Close(); count++; MessageBox.Show("打印完成:" + name, "提示", MessageBoxButtons.OK); } private void button2_Click(object sender, EventArgs e) { WatchStartOrSopt(false); } private void button3_Click(object sender, EventArgs e) { WatchStartOrSopt(true); } } }
然后写一个生成文件的程序用于测试,由于可能需要多个写入一起跑,采用传入参数的方式进行调用程序。共三个参数:第一个为标识,第二个为生成文件的数量,第三个为开始运行的时间:
如 FileCreater.exe 1 1000 121000 则表示这个实例的名称为1,连续生成1000个文件,在12:10:00开始执行。
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.IO; using System.Linq; using System.Text; using System.Windows.Forms; namespace FileCreater { public partial class Form1 : Form { string filePre = ""; string startTime = ""; public Form1(string[] args) { filePre = args[0]; startTime = args[2]; InitializeComponent(); timer1.Interval = 100; timer1.Tick += button1_Click; timer1.Enabled = true; this.Text = "FileCreater" + filePre + "_" + startTime; this.numericUpDown1.Value = int.Parse(args[1]); } private void button1_Click(object sender, EventArgs e) { label3.Text = DateTime.Now.ToString("HHmmss") + "|" + startTime; if (int.Parse(DateTime.Now.ToString("HHmmss")) > int.Parse(startTime)) { label3.Text = numericUpDown1.Value.ToString(); for (int i = 1; i <= numericUpDown1.Value; i++) { //string time = DateTime.Now.ToString("ddhhMMss"); string file = string.Format(@"{0}\{1}_{2}.tr", textBox1.Text, i, filePre); FileStream fs = new FileStream(file, FileMode.Append); StreamWriter sw = new StreamWriter(fs, Encoding.Default); sw.WriteLine(i.ToString()); sw.Close(); fs.Close(); } timer1.Stop(); } //MessageBox.Show("已完成", "提示", MessageBoxButtons.OK); Application.Exit(); } } }
测试过程中发现如下现象:
1.一个生成文件程序,连续生成10W的文件时会发生计数器记录下的值小于或多于10W