Hi Guys,
I am getting an error on a program i created, the program seems to work great so i started trying to cause problems (as users will generally do), I have found i can get it to crash if i remove the removable USB drive while it is compressing data to it, below is a small program i created to generate an error i have been having within the larger program (if anyone wants to try it and see):
It just needs one Button and two labels on a form and System.IO.Compression and System.IO.Compression.FileSystem added as references.
I put some stuff into the "C:\Temp\Test" directory, this will be zipped onto the flash drive located in the SaveLoc variable in this case "E:" when the button is clicked, make sure there is enough in the temp\test directory to take a little time to compress, i have about 23MB of images and audio this takes about 4-6 seconds to compress and save the files.
Once you click the button wait a second and then remove the USB flash drive (please use a clean drive as i would hate for anything you have on the drive becoming corrupt due to bad removal). I have had to do this 3 or 4 times before it shows the error below:
The immediate window shows:
The other error message i can get is still a IOException but the detail is: 'The volume for a file has been externally altered so that the opened file is no longer valid.'
I know people shouldn't remove USD brives while they are being written too, but i expect some users will and then moan that the app crashes.
I have checked the Exceptions settings in the IDE and nothing is checked:
so i dont understand how sometimes it can be removed with no error and the try/catch working to catch the problem and other times it crashed the program.
Any ideas would be welcome.
Regards
Stu
I am getting an error on a program i created, the program seems to work great so i started trying to cause problems (as users will generally do), I have found i can get it to crash if i remove the removable USB drive while it is compressing data to it, below is a small program i created to generate an error i have been having within the larger program (if anyone wants to try it and see):
It just needs one Button and two labels on a form and System.IO.Compression and System.IO.Compression.FileSystem added as references.
VB.NET:
Imports System.Windows.Forms
Imports System
Imports System.Runtime.InteropServices
Imports System.ComponentModel
Imports System.IO
Imports System.IO.Compression
Imports System.IO.DriveInfo
Imports System.Management
Imports System.Xml
Imports System.Threading
Public Class Form1
Private WithEvents bw As BackgroundWorker = New BackgroundWorker
Dim SaveLoc As String = "E:\"
Dim startedCompress As Boolean = False
Delegate Sub SetTextCallback([text] As String)
Private demoThread As Thread = Nothing
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Try
bw.RunWorkerAsync()
Catch ex As Exception
SetText2(DateTime.Now.ToString & " - Could not Compress files1: " & ex.Message)
bw.CancelAsync()
bw.Dispose()
End Try
End Sub
Private Sub SetText1(ByVal [text] As String)
' InvokeRequired required compares the thread ID of the
' calling thread to the thread ID of the creating thread.
' If these threads are different, it returns true.
If Label1.InvokeRequired Then
Dim d As New SetTextCallback(AddressOf SetText1)
Me.Invoke(d, New Object() {[text]})
Else
Label1.Text = [text]
End If
End Sub
Private Sub SetText2(ByVal [text] As String)
' InvokeRequired required compares the thread ID of the
' calling thread to the thread ID of the creating thread.
' If these threads are different, it returns true.
If Label2.InvokeRequired Then
Dim d As New SetTextCallback(AddressOf SetText2)
Me.Invoke(d, New Object() {[text]})
Else
Label2.Text = [text]
End If
End Sub
Private Sub doCompress(ByVal fn As String)
Try
If Directory.Exists(Mid$(SaveLoc, 1, 3)) Then
startedCompress = True
If Not (fn.Contains("TestAudio")) And fn <> "" Then
Dim fileName As String = System.IO.Path.GetFileName(fn)
Dim dirname As String = DateTime.Now.ToString("yyyyMMdd-HHmmss")
If My.Computer.FileSystem.DirectoryExists(SaveLoc & "\" & dirname) = False Then
My.Computer.FileSystem.CreateDirectory(SaveLoc & "\" & dirname)
End If
Dim wavCompressname = "SND-" & fileName & ".zip"
Dim wavName = fileName & ".wav"
'Do Audio
If System.IO.File.Exists(SaveLoc & wavCompressname) Then
System.IO.File.Delete(SaveLoc & wavCompressname)
End If
Dim audDir As String = fn & "\"
Dim ZipDir As String = SaveLoc & dirname & "\" & wavCompressname
' Debug.Print("-------------------------------------------------" & fileName & "--------------------------")
'Debug.Print(DateTime.Now.ToString & " - Start Compress")
If File.Exists(ZipDir) Then
ZipDir = ZipDir.Replace(".zip", "-1.zip")
' Debug.Print("file exists - renameing file to: " & ZipDir)
End If
Try
ZipFile.CreateFromDirectory(audDir, ZipDir, CompressionLevel.Optimal, False)
Catch ex As Exception
SetText2(DateTime.Now.ToString & " - Zip Error")
bw.CancelAsync()
bw.Dispose()
End Try
startedCompress = False
End If
End If
Catch dirNotFound As System.IO.DirectoryNotFoundException
' Code to handle DirectoryNotFoundException.
SetText2(DateTime.Now.ToString & " - Directory Not Found: ")
bw.CancelAsync()
bw.Dispose()
Catch fileNotFound As System.IO.FileNotFoundException
' Code to handle FileNotFoundException.
SetText2(DateTime.Now.ToString & " - File Not Found: ")
bw.CancelAsync()
bw.Dispose()
Catch *********** As System.IO.***********Exception
' Code to handle ***********Exception.
SetText2(DateTime.Now.ToString & " - Path Too Long: ")
bw.CancelAsync()
bw.Dispose()
Catch ioEx As System.IO.IOException
' Code to handle IOException.
SetText2(DateTime.Now.ToString & " - IO: ")
bw.CancelAsync()
bw.Dispose()
Catch security As System.Security.SecurityException
' Code to handle SecurityException.
SetText2(DateTime.Now.ToString & " - Security: ")
bw.CancelAsync()
bw.Dispose()
Catch ex As Exception
SetText2(DateTime.Now.ToString & " - Could not Compress files: " & ex.Message)
bw.CancelAsync()
bw.Dispose()
End Try
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
bw.WorkerSupportsCancellation = True
bw.WorkerReportsProgress = True
AddHandler bw.DoWork, AddressOf bw_DoWork
AddHandler bw.RunWorkerCompleted, AddressOf bw_RunWorkerCompleted
End Sub
Private Sub bw_DoWork(sender As Object, e As DoWorkEventArgs) Handles bw.DoWork
SetText1(DateTime.Now.ToString & " - BW Started")
Try
If bw.CancellationPending = True Then
e.Cancel = True
Else
'do work
doCompress("C:\Temp\Test")
End If
Catch ex As Exception
Debug.Print(DateTime.Now.ToString & " - Unable to start background worker thread: " & ex.Message)
bw.CancelAsync()
bw.Dispose()
End Try
End Sub
Private Sub bw_ProgressChanged(sender As Object, e As ProgressChangedEventArgs) Handles bw.ProgressChanged
SetText2("Prog Changed")
End Sub
Private Sub bw_RunWorkerCompleted(sender As Object, e As RunWorkerCompletedEventArgs) Handles bw.RunWorkerCompleted
SetText1(DateTime.Now.ToString & " - BW Complete")
End Sub
End ClassI put some stuff into the "C:\Temp\Test" directory, this will be zipped onto the flash drive located in the SaveLoc variable in this case "E:" when the button is clicked, make sure there is enough in the temp\test directory to take a little time to compress, i have about 23MB of images and audio this takes about 4-6 seconds to compress and save the files.
Once you click the button wait a second and then remove the USB flash drive (please use a clean drive as i would hate for anything you have on the drive becoming corrupt due to bad removal). I have had to do this 3 or 4 times before it shows the error below:
The immediate window shows:
The other error message i can get is still a IOException but the detail is: 'The volume for a file has been externally altered so that the opened file is no longer valid.'
I know people shouldn't remove USD brives while they are being written too, but i expect some users will and then moan that the app crashes.
I have checked the Exceptions settings in the IDE and nothing is checked:
so i dont understand how sometimes it can be removed with no error and the try/catch working to catch the problem and other times it crashed the program.
Any ideas would be welcome.
Regards
Stu
