Mit freundlichen Gr??en
DotNetErbse


[Es hei?t Paket und nicht Packet, auch wenn Standard augenscheinlich von Standar(t)e kommt,hei?t es dennoch Standar(d)]

Beitrag wurde zuletzt am 26.09.15 um 07:38:37 editiert.

Public Function CheckIfFileIsFree (ByVal Dateiname As String) As Boolean
 
Dim Datei_verfuegbar As Boolean
 
Dim fs As FileStream 
fs = New FileStream(Dateiname, FileMode.Open, FileAccess.ReadWrite, _
  FileShare.None)
Dim sr As StreamReader
 
Do
  Datei_verfuegbar = True
 
  Try
     sr = New StreamReader(fs)
     sr.close()
  Catch ex As IOException
     Datei_verfuegbar = False  'Datei gesperrt
  Catch ex As Exception
     msgbox(ex.Message, MsgBoxStyle.Exclamation)  'andere Fehler melden 
  End Try
 
  Thread.Sleep(100) 'kurz warten
 
Loop Until Datei_verfuegbar = True
 
' Aufräumen
sr.dispose()
 
Return Datei_verfuegbar
 
End Function

Public Class frmFileSystemWatcherDemo
 
    Dim WithEvents fsw As New IO.FileSystemWatcher
 
    'Controls
    Dim lblcreated As New Label With _
        {.Parent = Me, .Width = 300}
 
    Dim lblchanged As New Label With _
        {.Parent = Me, .Top = 30, .Width = 300}
 
    Dim lblend As New Label With _
        {.Parent = Me, .Top = 60, .Width = 300}
 
 
    Dim txtFile As New TextBox With _
        {.Parent = Me, .Top = 100, .Width = 300, .Height = 150, _
         .Multiline = True}
 
 
    Delegate Sub changetypedel(ByVal ct As IO.WatcherChangeTypes)
    Dim Show_Text As New changetypedel(AddressOf Notify_changed)
 
 
    Dim filepath As String = "C:\daten\fsw.csv" 'zu überwachendes File
 
 
    Private Sub frmFileSystemWatcherDemo_Load(sender As System.Object, _
                          e As System.EventArgs) Handles MyBase.Load
 
        'Sicher stellen, daß die Datei nicht vorhanden ist
        IO.File.Delete(filepath)
 
        'Einrichten des Filesystemwatchers
        With fsw
            .BeginInit()
            .Filter = "*.csv"
            .NotifyFilter = _
                IO.NotifyFilters.FileName Or IO.NotifyFilters.Size
            .Path = IO.Path.GetDirectoryName(filepath)
            .EnableRaisingEvents = True
            .EndInit()
        End With
 
        Me.Show()
 
        'Thread zum Erstellen und Füllen der Datei 
        Dim t As New Threading.Thread _
           (New Threading.ThreadStart(AddressOf CreateAndFill))
 
        t.Start()
 
    End Sub
 
 
    '====================================================
    'FSW-Eventverarbeitung
    '==================================================== 
 
    Private Sub Notify_created()
        lblcreated.Text = "FSW erstellt: " & Now.ToString
    End Sub
 
    Private Sub fsw_Created(sender As Object, _
        e As System.IO.FileSystemEventArgs) Handles fsw.Created
        Me.Invoke(New MethodInvoker(AddressOf Notify_created))
    End Sub
 
 
    Private Sub Notify_changed(Changetype As IO.WatcherChangeTypes)
        lblchanged.Text = _
        "FSW geändert: " & Now.ToString & " " & Changetype.ToString
 
        'Dateiinhalt nach dem Changed-Event lesen
        txtFile.Text = IO.File.ReadAllText(filepath)
        Me.Refresh()
    End Sub
 
    Private Sub fsw_Changed(sender As Object, _
        e As System.IO.FileSystemEventArgs) Handles fsw.Changed
        Me.Invoke(Show_Text, {e.ChangeType})
    End Sub
 
 
    '===================================================
    'Thread zum Füllen der Datei
    '===================================================
 
 
    Private Sub Notify_ThreadEnd()
        'CreateAndFill-Thread wird beendet 
        lblend.Text = "Thread beendet: " & Now.ToString
    End Sub
 
 
    Private Sub CreateAndFill()
 
        'Filestream exclusiv öffnen
        Using fs As New IO.FileStream(filepath, IO.FileMode.CreateNew, _
                              IO.FileAccess.Write, IO.FileShare.None), _
              bw As New IO.BinaryWriter(fs)
 
              For i As Integer = 0 To 10
                 bw.Write("Zeile " & CStr(i) & ";" & Now.ToString & vbCrLf)
 
                 Threading.Thread.Sleep(1000) 'Verzögerung
              Next i
 
              'End Using schließt den Filestream / Dateifreigabe
        End Using
 
        'Zeitpunkt der Dateifreigabe anzeigen
        Me.Invoke(New MethodInvoker(AddressOf Notify_ThreadEnd))
    End Sub
 
End Class

    ''' <summary>
    ''' Prueft ob die Datei noch im Zugriff ist
    ''' </summary>
    ''' <param name="fileName"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Private Function IsFileOpen(ByVal fileName As String) As Boolean
        Try
            If File.Exists(fileName) Then
                Dim stream As FileStream = File.Open(fileName, FileMode.Open, _
                  FileAccess.Read, FileShare.None)
                stream.Dispose()
            End If
            Return False
        Catch ex As IOException
            ex = Nothing
            Return True
        End Try
    End Function

                While IsFileOpen(e.FullPath) = True
                    Threading.Thread.Sleep(100)
                End While

Mit freundlichen Gr??en
DotNetErbse


[Es hei?t Paket und nicht Packet, auch wenn Standard augenscheinlich von Standar(t)e kommt,hei?t es dennoch Standar(d)]

Mit freundlichen Gr??en
DotNetErbse


[Es hei?t Paket und nicht Packet, auch wenn Standard augenscheinlich von Standar(t)e kommt,hei?t es dennoch Standar(d)]

   While IsFileOpen(e.FullPath) = True
        Threading.Thread.Sleep(100)
    End While