C# FileSystemWatcher 监视磁盘文件变更

简化需求:有一个简化了的需求是这样的:有一个拍照程序在运行,一旦抓拍之后则将图片文件存储至某目录,然后图片要上传至远程服务器并update数据库。

原需求:原先的需求是这样的:有一台PDA扫码枪,一个IP照相机放置在下线区传送带上方。当PDA扫描箱子上的条码,触发相机拍照,将图片流传至远端服务器,找到对应的条码,将图片存储并更新数据库。

 

然而我不知道PDA扫描的瞬间如何与IP相机通信(蓝牙或WLAN?),其实关键是我不知道怎样使用IP相机的外触发功能,增加蓝牙触发器?也不知道怎样hack或ssh到这个相机(应该是linux的吧),所以只能先使用简化需求的版本。

 

而简化需求的版本,关键就是监视文件夹内容变化与上传文件流。

昨天问了下度娘,C#中的监视组件名字叫做FileSystemWatcher。

于是写了个demo,可以监视所有逻辑盘或者某个文件夹。

使用方法:

1.直接打开是监视所有逻辑磁盘文件变化。

2.或者传递参数,监视某一路径文件变化。如图,监视e盘

 

源代码:

  1 namespace FileSystemWatcherDemo
  2 {
  3     class Program
  4     {
  5         static void Main(string[] args)
  6         {
  7             //watcher组
  8             FileSystemWatcher[] watchers;
  9 
 10             //若未传递参数,则监视所有文件系统,包括CD-ROM(不可用),可移动磁盘(不可用)等
 11             if (args.Length == 0)
 12             {
 13                 string[] drivers = Directory.GetLogicalDrives();
 14                 watchers = new FileSystemWatcher[drivers.Length];
 15 
 16                 for (int i = 0; i < drivers.Length; i++)
 17                 {
 18                     try
 19                     {
 20                         watchers[i] = new FileSystemWatcher { Path = drivers[i] };
 21                     }
 22                     catch (Exception ex)
 23                     {
 24                         Trace.TraceWarning(ex.Message);
 25                     }
 26                 }
 27             }
 28             else
 29             {
 30                 watchers = new FileSystemWatcher[1];
 31                 watchers[0] = new FileSystemWatcher { Path = args[0] };
 32             }
 33 
 34             foreach (FileSystemWatcher w in watchers)
 35             {
 36                 if (w == null) continue;
 37 
 38                 w.Filter = "*";
 39                 w.IncludeSubdirectories = true;
 40                 w.EnableRaisingEvents = true;
 41 
 42                 w.Created += onFileSystem_Changed;
 43                 w.Deleted += onFileSystem_Changed;
 44                 w.Changed += onFileSystem_Changed;
 45                 w.Renamed += watcher_Renamed;
 46             }
 47 
 48             Console.ReadLine();
 49         }
 50 
 51         #region [ 检测文件是否占用 ]
 52         /// <summary>
 53         /// 检测文件是否占用
 54         /// </summary>
 55         /// <param name="filename"></param>
 56         /// <returns></returns>
 57         static bool IsFileReady(string filename)
 58         {
 59             var fi = new FileInfo(filename);
 60             FileStream fs = null;
 61             try
 62             {
 63                 fs = fi.Open(FileMode.Open, FileAccess.Read, FileShare.None);
 64                 return true;
 65             }
 66             catch (IOException)
 67             {
 68                 return false;
 69             }
 70 
 71             finally
 72             {
 73                 if (fs != null)
 74                     fs.Close();
 75             }
 76         }
 77         #endregion
 78 
 79         private static volatile object _lock = true;
 80         static void onFileSystem_Changed(object sender, FileSystemEventArgs e)
 81         {
 82             lock (_lock)
 83             {
 84                 Console.ForegroundColor = ConsoleColor.DarkGray;
 85                 Console.Write("[");
 86                 Console.Write(DateTime.Now.ToString("HH:mm:ss"));
 87                 Console.Write("] ");
 88 
 89                 switch (e.ChangeType.ToString().ToLower())
 90                 {
 91                     case "created":
 92                         //while (!IsFileReady(e.FullPath))
 93                         //{
 94                         //    if (!File.Exists(e.FullPath))
 95                         //        return;
 96                         //    Thread.Sleep(100);
 97                         //}
 98                         Console.ForegroundColor = ConsoleColor.Green;
 99                         Console.Write(e.ChangeType);
100                         Console.ForegroundColor = ConsoleColor.White;
101                         Console.Write(" ");
102                         Console.Write(e.Name);
103                         Console.Write(" ");
104                         Console.ForegroundColor = ConsoleColor.DarkGray;
105                         Console.Write(e.FullPath);
106 
107                         break;
108                     case "deleted":
109                         Console.ForegroundColor = ConsoleColor.Red;
110                         Console.Write(e.ChangeType);
111                         Console.ForegroundColor = ConsoleColor.White;
112                         Console.Write(" ");
113                         Console.Write(e.Name);
114                         Console.Write(" ");
115                         Console.ForegroundColor = ConsoleColor.DarkGray;
116                         Console.Write(e.FullPath);
117                         break;
118                     case "changed":
119                         Console.ForegroundColor = ConsoleColor.Cyan;
120                         Console.Write(e.ChangeType);
121                         Console.ForegroundColor = ConsoleColor.White;
122                         Console.Write(" ");
123                         Console.Write(e.Name);
124                         Console.Write(" ");
125                         Console.ForegroundColor = ConsoleColor.DarkGray;
126                         Console.Write(e.FullPath);
127                         break;
128                 }
129 
130                 Console.Write("\r\n");
131             }
132         }
133         static void watcher_Renamed(object sender, RenamedEventArgs e)
134         {
135             Console.ForegroundColor = ConsoleColor.Magenta;
136             Console.Write(e.ChangeType);
137             Console.ForegroundColor = ConsoleColor.White;
138             Console.Write(" ");
139             Console.Write(e.OldName);
140             Console.Write(e.OldFullPath);
141             Console.ForegroundColor = ConsoleColor.Yellow;
142             Console.Write(" ");
143             Console.Write(e.Name);
144             Console.Write(e.FullPath);
145             Console.Write(Thread.CurrentThread.Name);
146             Console.Write("\r\n");
147         }
148     }
149 }

 

仍有bug,望高手指正。

附上编译好的exe,可以直接运行。

 

posted @ 2014-11-18 09:17  Lison Liou  Views(3557)  Comments(9Edit  收藏  举报