VB.Net FileSystemWatcher -多文件夹和多文件

Question

我需要监控一个根文件夹，该根文件夹下有多个文件夹，每个文件夹包含多个文件(.csv)，这些文件是使用其他第三方工具从服务器复制到工作站的。我必须监视工作站根目录的文件夹，并且当在任意子文件夹中创建或更新.csv文件时，我必须将.csv文件数据(更新的或新的)写入sql server数据库。在将数据写入sql server时，我需要捕获在其中更新/创建.csv文件的子文件夹名。这样，我就可以在一个数据库文件中拥有单独的文件夹数据。

在工作站pc上运行程序时，应用程序崩溃，没有任何特定的错误消息。由于该应用程序是在远程pc上运行的，因此我无法调试该应用程序来检查哪条线路导致了崩溃。代码如下：

Public Class FolderWatchAndProcess
Dim blnMonitorUpdated As Boolean = True
Dim blnMonitorCreated As Boolean = True
Dim blnShowMessage As Boolean
Dim strFullFileName As String
Dim strFileName As String
Dim strFolderName As String
Private Delegate Sub updateLabel(ByVal newLabel As String)

Private Sub updateLabelHandler(ByVal labelText As String)
    lblMetNo.Text = labelText
End Sub

Private Sub ReadAndInsertCSVData()
' This routine checks for duplicates and inserts new records into the sql server database
End Sub

Private Sub Form_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    'lblMonitorPath.Text = "C:\RootFolder\"
    'btnStartWatching_Click(Nothing, Nothing)
    'Me.WindowState = FormWindowState.Minimized
End Sub

Private Sub btnStartWatching_Click(sender As Object, e As EventArgs) Handles btnStartWatching.Click
    btnStartWatching.Text = "Stop Watching"
    Dim aFileWatcherInstance As ArrayList = New ArrayList
    For Each sMonitorFolder As String In lstFolders.Items
        If IO.Directory.Exists(sMonitorFolder) Then
            Dim oFileWatcher As FileSystemWatcher = New FileSystemWatcher
            oFileWatcher.Path = sMonitorFolder
            oFileWatcher.Filter = "*.CSV"
            If blnMonitorUpdated Then
                AddHandler oFileWatcher.Changed, AddressOf Me.FileSystemWatcherUpdated
            Else
                'RemoveHandler , AddressOf Me.FileSystemWatcherUpdated
            End If
            If blnMonitorCreated Then
                AddHandler oFileWatcher.Created, AddressOf Me.FileSystemWatcherCreated
            Else
                'RemoveHandler , AddressOf Me.FileSystemWatcherCreated
            End If
            oFileWatcher.EnableRaisingEvents = True
            aFileWatcherInstance.Add(oFileWatcher)
        End If
    Next
End Sub

Private Sub FileSystemWatcherCreated(ByVal sender As Object, ByVal e As System.IO.FileSystemEventArgs)
    strFullFileName = e.FullPath
    strFileName = Mid(e.Name, 3, Len(e.Name))
    strFolderName = strFileName.Split("_")(0)
    If Me.InvokeRequired Then
        Dim d As New updateLabel(AddressOf updateLabelHandler)
        Me.BeginInvoke(d, New Object() {strFolderName})
    Else
        updateLabelHandler(strFolderName)
    End If
    ReadAndInsertCSVData()
End Sub

Private Sub FileSystemWatcherDeleted(ByVal sender As Object, ByVal e As System.IO.FileSystemEventArgs)
    'A file has been deleted from the child directory.
End Sub

Private Sub FileSystemWatcherUpdated(ByVal sender As Object, ByVal e As System.IO.FileSystemEventArgs)
    strFullFileName = e.FullPath
    strFileName = Mid(e.Name, 3, Len(e.Name))
    strFolderName = strFileName.Split("_")(0)
    If Me.InvokeRequired Then
        Dim d As New updateLabel(AddressOf updateLabelHandler)
        Me.BeginInvoke(d, New Object() {strFolderName})
    Else
        updateLabelHandler(strFolderName)
    End If
    ReadAndInsertCSVData()
End Sub

结束类

任何帮助都将不胜感激。

Answer 1

Changed事件将多次触发：

https://msdn.microsoft.com/en-us/library/system.io.filesystemwatcher.changed(v=vs.110).aspx

也许你可以使用这里提到的IsFileLocked函数：

I keep getting exception sometimes on System.Threading.Tasks.TaskCompletionSource how can i solve it?