C# 開發 Windows Service 程序（下）：MyFileSystemWatcherService 完整啟動流程與事件綁定

服務類別定義

MyFileSystemWatcherService 繼承 ServiceBase，核心啟動方法 StartFileSystemWatching：

private ArrayList myWatchers = null;

internal bool StartFileSystemWatching() {
    myWatchers = new ArrayList();
    MyConfig.Instance.Load();
    string[] paths = MyConfig.Instance.WatchedPaths;
    StringBuilder pathList = new StringBuilder();

    if (paths != null) {
        foreach (string path in paths) {
            if (!Path.IsPathRooted(path)) continue;

            string basePath, filter;
            if (Directory.Exists(path)) { basePath = path; filter = "*.*"; }
            else { basePath = Path.GetDirectoryName(path); filter = Path.GetFileName(path); }
            if (basePath == null) continue;
            basePath = basePath.Trim();

            if (basePath.ToUpper().StartsWith(Application.StartupPath.ToUpper())) continue;
            if (!Directory.Exists(basePath)) continue;

            if (pathList.Length > 0) pathList.Append(";");
            pathList.Append(path);

            FileSystemWatcher watcher = new FileSystemWatcher();
            watcher.Path = basePath;
            watcher.Filter = filter;
            watcher.EnableRaisingEvents = true;
            watcher.IncludeSubdirectories = false;

            if (MyConfig.Instance.LogChanged)
                watcher.Changed += (s, e) => WriteFileSystemLog(e.FullPath, e.ChangeType.ToString());
            if (MyConfig.Instance.LogCreated)
                watcher.Created += (s, e) => WriteFileSystemLog(e.FullPath, e.ChangeType.ToString());
            if (MyConfig.Instance.LogDeleted)
                watcher.Deleted += (s, e) => WriteFileSystemLog(e.FullPath, e.ChangeType.ToString());
            if (MyConfig.Instance.LogRenamed)
                watcher.Renamed += (s, e) => WriteFileSystemLog(e.FullPath, e.ChangeType.ToString());

            myWatchers.Add(watcher);
        }
        EventLog.WriteEntry("開始監視檔案系統 " + pathList, EventLogEntryType.Information);
    }
    return true;
}

事件日誌寫入

private void WriteFileSystemLog(string objectName, string eventStyle) {
    IDbConnection conn = Util.DBConnection;
    if (conn == null) return;
    using (IDbCommand cmd = conn.CreateCommand()) {
        cmd.CommandText = "INSERT INTO FileSystemLog (RecordID, WatchTime, ObjectName, EventStyle) VALUES ('" 
            + Guid.NewGuid() + "', '" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + "', ?, '" + eventStyle + "')";
        IDbDataParameter p = cmd.CreateParameter();
        p.Value = objectName;
        cmd.Parameters.Add(p);
        cmd.ExecuteNonQuery();
    }
}

服務控制覆寫

protected override void OnStart(string[] args) { StartFileSystemWatching(); }

protected override void OnStop() {
    if (myWatchers != null) {
        foreach (FileSystemWatcher w in myWatchers) {
            w.EnableRaisingEvents = false;
            w.Dispose();
        }
        myWatchers = null;
    }
    Util.CloseDBConnection();
    base.OnStop();
}