Daten Kopieren - Kommt nie an

  • VB.NET

Es gibt 1 Antwort in diesem Thema. Der letzte Beitrag () ist von Bluespide.

    Daten Kopieren - Kommt nie an

    Hi,
    habe im Internet ein Code gefunden, wie man mit Multithreading. Bei grossen dateien reagiert's nicht mehr und bei kleinen sachen kommt die datei nie an...
    Hier der Code:

    VB.NET-Quellcode

    1. Imports System.IO
    2. Imports System.ComponentModel
    3. Public Class Form1
    4. Private th As BackgroundWorker
    6. ' wieviele Bytes wurden kopiert
    7. Private lngBytesCopied As Long
    9. ' Die Speicheradresse der Zieldatei
    10. Private lngSourceFileLength As Long
    12. Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
    13. If th.IsBusy Then
    14. th.CancelAsync()
    15. End If
    16. End Sub
    18. Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    19. th = New BackgroundWorker
    20. AddHandler th.DoWork, AddressOf th_DoWork
    21. AddHandler th.RunWorkerCompleted, AddressOf th_Completed
    22. AddHandler th.ProgressChanged, AddressOf th_ProgressChanged
    23. th.WorkerReportsProgress = True
    24. th.WorkerSupportsCancellation = True
    26. Me.lblSource.Text = ""
    27. Me.lblTarget.Text = ""
    28. Me.cmdCopyAsync.Enabled = False
    29. Me.cmdCancel.Enabled = False
    30. Me.progress.Visible = False
    31. Me.progress.Visible = False
    32. End Sub
    34. Private Sub cmdSelectSource_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdSelectSource.Click
    35. Dim openDlg As New OpenFileDialog
    36. With openDlg
    37. .Title = "Select file"
    38. .InitialDirectory = Application.StartupPath
    39. If .ShowDialog = Windows.Forms.DialogResult.OK Then
    40. Me.lblSource.Text = .FileName
    41. End If
    42. End With
    43. End Sub
    45. Private Sub cmdSelectTarget_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdSelectTarget.Click
    46. Dim fldBrowser As New FolderBrowserDialog
    47. With fldBrowser
    48. .ShowNewFolderButton = True
    49. If .ShowDialog = Windows.Forms.DialogResult.OK Then
    50. Me.lblTarget.Text = .SelectedPath
    51. Me.cmdCopyAsync.Enabled = True
    52. End If
    53. End With
    54. End Sub
    56. Private Sub cmdCopyAsync_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdCopyAsync.Click
    57. If Me.lblTarget.Text.Length > 0 And Me.lblSource.Text.Length > 0 Then
    58. Me.cmdCopyAsync.Enabled = False
    59. Me.progress.Minimum = 0
    60. Me.progress.Maximum = 100
    61. Me.progress.Visible = True
    62. Me.progress.Visible = True
    63. Me.cmdCancel.Enabled = True
    65. ' Start des Threads löst dann die th_DoWork Prozedur aus
    66. th.RunWorkerAsync()
    67. End If
    68. End Sub
    70. Private Sub th_Completed(ByVal sender As Object, _
    71. ByVal e As RunWorkerCompletedEventArgs)
    73. Dim strFinished As String = String.Empty
    75. If e.Cancelled Then
    76. strFinished = "Operation Cancelled"
    77. ElseIf e.Error IsNot Nothing Then
    78. strFinished = "Operation Error " & e.Error.Message
    79. Else
    80. strFinished = "Operation Sucessfull"
    81. End If
    83. MessageBox.Show("CopyThread finished" & vbCrLf & strFinished)
    84. Me.cmdCopyAsync.Enabled = True
    85. End Sub
    87. Private Sub cmdCancel_Click(ByVal sender As System.Object, _
    88. ByVal e As System.EventArgs) Handles cmdCancel.Click
    90. If th.IsBusy Then
    91. th.CancelAsync()
    92. End If
    93. End Sub
    95. Private Sub th_ProgressChanged(ByVal sender As Object, _
    96. ByVal e As ProgressChangedEventArgs)
    98. Try
    99. Me.lblProgress.Text = lngBytesCopied.ToString & " Bytes From " & _
    100. lngSourceFileLength.ToString & " Copied"
    101. Me.progress.Value = e.ProgressPercentage.ToString
    102. Catch ex As Exception
    103. MessageBox.Show(ex.Message)
    104. End Try
    105. End Sub
    107. Private Sub th_DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs)
    108. Dim fi As New FileInfo(Me.lblSource.Text)
    110. Dim inStream As FileStream = Nothing
    111. Dim outStream As FileStream = Nothing
    112. Dim buffer(2048) As Byte
    113. Dim offset As Integer = 0
    115. Try
    116. inStream = New FileStream(fi.FullName, FileMode.Open)
    117. outStream = New FileStream(Me.lblTarget.Text & "" & fi.Name, FileMode.Create)
    118. lngSourceFileLength = inStream.Length
    119. Do
    120. If th.CancellationPending = True Then
    121. e.Cancel = True
    122. inStream.Close()
    123. outStream.Close()
    124. Exit Sub
    125. End If
    126. offset = inStream.Read(buffer, 0, buffer.Length)
    127. outStream.Write(buffer, 0, offset)
    128. lngBytesCopied += offset
    130. ' WICHTIG: Hier könen wir einen Progress darstellen
    131. th.ReportProgress(offset / inStream.Length * 100)
    132. Loop Until offset = 0
    134. Catch ex As Exception
    135. MessageBox.Show(ex.Message)
    137. Finally
    138. inStream.Close()
    139. outStream.Close()
    140. End Try
    141. End Sub
    142. End Class


    Wo ist der Fehler? Es kommt nirgends eine Fehlermeldung

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