FileSystemWatcher不發射事件

Question

由於某種原因，我的FileSystemWatcher沒有發射任何事件。我想知道任何時候在我的目錄中創建，刪除或重命名新文件。 _myFolderPath正在設置正確，我已檢查。

這裏是我當前的代碼：

public void Setup() { 
    var fileSystemWatcher = new FileSystemWatcher(_myFolderPath); 
    fileSystemWatcher.NotifyFilter = NotifyFilters.LastAccess | 
     NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName; 

    fileSystemWatcher.Changed += FileSystemWatcherChanged; 
    fileSystemWatcher.Created += FileSystemWatcherChanged; 
    fileSystemWatcher.Deleted += FileSystemWatcherChanged; 
    fileSystemWatcher.Renamed += FileSystemWatcherChanged; 

    fileSystemWatcher.Filter = "*.*"; 
    fileSystemWatcher.EnableRaisingEvents = true; 
} 

private void FileSystemWatcherChanged(object sender, FileSystemEventArgs e) 
{ 
    MessageBox.Show("Queue changed"); 
    listBoxQueuedForms.Items.Clear(); 
    foreach (var fileInfo in Directory.GetFiles(_myFolderPath, "*.*", SearchOption.TopDirectoryOnly)) 
    { 
     listBoxQueuedForms.Items.Add(fileInfo)); 
    } 
} 

Answer 1

你似乎在創建FileSystemWatcher的作爲設置方法的局部變量。這種方法當然會在方法結束時超出範圍，並且很可能會在這一點上得到整理，從而消除手錶。

嘗試創建FSW的地方，它將被持續（例如一個程序級別的變量），看看是否這樣排序。

Answer 2

我的問題是我期望某些操作會導致事件觸發。例如，將文件（單擊並拖動）從桌面移動到觀看位置不會引發事件，而是複製現有文件並粘貼其新副本（通過創建新文件到文件系統而不是簡單地移動現有的）導致Changed事件被提出。

我的解決方案是將每個NotifyFilter添加到我的FileSystemWatcher。通過這種方式，我會在FileSystemWatcher能夠通知我的所有情況下收到通知。

注意它不是完全直觀/明顯的哪些過濾器會通知您的具體情況。例如，我預計如果我包含FileName，那麼我將被告知對現有文件名稱所做的任何更改......而不是Attributes似乎可以處理這種情況。

watcher.NotifyFilter = NotifyFilters.Attributes | 
    NotifyFilters.CreationTime | 
    NotifyFilters.FileName | 
    NotifyFilters.LastAccess | 
    NotifyFilters.LastWrite | 
    NotifyFilters.Size | 
    NotifyFilters.Security; 

Answer 3

我們剛剛有一個非常類似的問題，移動一個文件夾沒有觸發預期的事件。解決方案是複製整個文件夾，而不是僅僅移動它。

DirectoryCopy(".", ".\\temp", True) 

Private Shared Sub DirectoryCopy(_ 
     ByVal sourceDirName As String, _ 
     ByVal destDirName As String, _ 
     ByVal copySubDirs As Boolean) 

     ' Get the subdirectories for the specified directory. 
     Dim dir As DirectoryInfo = New DirectoryInfo(sourceDirName) 

     If Not dir.Exists Then 
      Throw New DirectoryNotFoundException(_ 
       "Source directory does not exist or could not be found: " _ 
       + sourceDirName) 
     End If 

     Dim dirs As DirectoryInfo() = dir.GetDirectories() 
     ' If the destination directory doesn't exist, create it. 
     If Not Directory.Exists(destDirName) Then 
      Directory.CreateDirectory(destDirName) 
     End If 
     ' Get the files in the directory and copy them to the new location. 
     Dim files As FileInfo() = dir.GetFiles() 
     For Each file In files 
      Dim temppath As String = Path.Combine(destDirName, file.Name) 
      file.CopyTo(temppath, False) 
     Next file 

     ' If copying subdirectories, copy them and their contents to new location. 
     If copySubDirs Then 
      For Each subdir In dirs 
       Dim temppath As String = Path.Combine(destDirName, subdir.Name) 
       DirectoryCopy(subdir.FullName, temppath, true) 
      Next subdir 
     End If 
    End Sub 

Answer 4

使用此setter啓用觸發器：

watcher.EnableRaisingEvents = true;