Deleting a file after closing - vb.net

I'm trying to get my app to delete a pdf file after the Acrobat Reader (with this file) closes.
If I do this:
Process.Start("d:\test.pdf")
My.Computer.FileSystem.DeleteFile("d:\test.pdf")
Acrobat gives me an error: "There was an error opening this document. This file cannot be found."
Any help will be appreciated, Thanks
EDIT
I modified the code a little bit...
Dim MyProc = Process.Start(path)
MyProc.WaitForExit()
My.Computer.FileSystem.DeleteFile(path)
And it deletes the PDF after it is closed, but not if there is another PDF opened...

You could just use the event from your process to get the job done.
Dim MyProc = System.Diagnostics.Process.Start("d:\test.pdf")
AddHandler MyProc.Exited, Sub() My.Computer.FileSystem.DeleteFile("d:\test.pdf")

u can add a timer and set timer to check if acrobart.exe is running :
Public sub Btn1_click
Process.Start("file path here")
Timer1.start
Public sub Timer1_tick
Dim pr As Process() = Process.GetProcessesByName("acrobat") 'change acrobat with necessary exe name as i can't remember the exact name of acrobat.exe , it could be acrobat32 or acrobat64 or just acrobat as mentioned
If pr.Length = 0 Then
timer1.stop
My.Computer.FileSystem.DeleteFile("d:\test.pdf")
Else
End If
This will get the job done!

Related

Hangman System.IO.IOException' occurred in mscorlib.dll

i am creating a hangman game that is to be used on a few computers, i have created the hangman game itself but i am using the "load form" function to create the list when the program first starts, but i am having this issue.
An unhandled exception of type 'System.IO.IOException' occurred in mscorlib.dll
Additional information: The process cannot access the file 'h:\Bryson\words.txt' because it is being used by another process.
Using sw As StreamWriter = File.CreateText("h:\Bryson\words.txt")
^^that line is where the error pops up^^
I have inserted some in code Comments to make life easier. If anyone can help thanks in advance :)
'USED TO CREATE HANGMAN FILE IF NOT FOUND
Private Sub main_Load(sender As Object, e As EventArgs) Handles MyBase.Load
fofound = False
fifound = False
MsgBox("remove this and change file path and fix qu2 quiz")
'DESIGNER USE
Dim path As String = "h:\Bryson\words.txt"
'CREATE VAR FOR PATH
If System.IO.Directory.Exists("h:\Bryson") Then
'CHECKS IF FOLDER EXISTS
fofound = True
Else
'IF IT DOES THEN IT MOVES ON
System.IO.Directory.CreateDirectory("h:\Bryson")
'IF NOT IT CREATES THE FOLDER
fofound = True
If File.Exists("h:\Bryson\test\words.txt") Then
'CHECKS IF FILE EXISTS
fifound = True
Else
'IF IT DOES IT MOVES ON
IO.File.Create("h:\Bryson\words.txt")
'IF NOT IT CREATES IT
FileClose()
End If
End If
If fofound And fifound = True Then
Else
Using sw As StreamWriter = File.CreateText("h:\Bryson\words.txt")
'CRASH POINT The process cannot access the file 'C:\Bryson\words.txt'
'because it Is being used by another process.
sw.WriteLine("Hangman")
sw.WriteLine("computer")
sw.WriteLine("electrode")
sw.WriteLine("independent")
sw.WriteLine("stream")
sw.WriteLine("enforcing")
End Using
'WRITES TO FILE
MsgBox("file created")
'DESIGNER USE
FileClose()
'CLOSES FILE
End If
End Sub
FileClose() is a legacy function from VB6 and will not affect anything in the System.IO namespace. To close a file you need to call .Close() or .Dispose() on the stream that has opened the file (wrapping the stream in a Using block does this automatically).
Your problem is this line:
IO.File.Create("h:\Bryson\words.txt")
The method creates a new file and opens a FileStream to it which locks the file. Since you never close the returned FileStream your file will remain locked until you close your application.
The File.Create() call is completely unnecessary though because File.CreateText() will create the file if it doesn't exist. So you should just remove the above line.

Using Filewatcher for a progress bar with subdirectories, Wont Update Properly

I'm trying to copy Files from a local Computer to a Network device. I'm trying to get a Progress Bar working for the File copy, and got it working for a Single Directory with no Subdirectory:
Private Sub CopyPictures()
Try
If Not Directory.Exists(DestinationPath) Then
My.Computer.FileSystem.CreateDirectory(DestinationPath)
End If
Dim counterLocalFiles = My.Computer.FileSystem.GetFiles(SourcePath)
UpdateProgressBarMaximum1(CInt(counterLocalFiles.Count))
UpdateLabelText2(CStr(counterLocalFiles.Count)) 'is a label which shows copied X files of Label2 Files
fsw1 = New IO.FileSystemWatcher(DestinationPath)
fsw1.EnableRaisingEvents = True
My.Computer.FileSystem.CopyDirectory(SourcePath, DestinationPath)
GetSettingsFromFile()
Catch Exec As System.IO.IOException
Dim dr As DialogResult = MessageBox.Show("Some Random Error Code", "Exception Title", MessageBoxButtons.OKCancel)
If (Not DialogResult.OK = dr) Then
Exit Sub
Return
End If
End Try
End Sub
Private Sub fsw1_Created(sender As Object, e As FileSystemEventArgs) Handles fsw1.Created
Dim counterRemoteFiles = My.Computer.FileSystem.GetFiles(DestinationPath)
UpdateProgressBar1(CInt(counterRemoteFiles.Count))
UpdateLabelText1(CStr(counterRemoteFiles.Count))
End Sub
The Update ObjectX Subs are just invoke Functions since the CopyPictures is raised by a backgroundworker as well looking all like this one for example
Private Sub UpdateProgressBar1(Value As Int32)
If ProgressBar1.InvokeRequired Then
ProgressBar1.Invoke(New Action(Of Integer)(AddressOf UpdateProgressBar1), Value)
Else
'We are on the UI thread so update the control.
ProgressBar1.Value = Value
End If
End Sub
This code works perfectly fine for me, but I have to deal with SubDirectories which contain the Images, and the names of the subs are random so i cant predetermine them so I came up with slight changes:
The Counter is looking now like this:
Dim counterLocalFiles = System.IO.Directory.GetFiles(SourcePath, "*.jpg*", SearchOption.AllDirectories).Length
UpdateProgressBarMaximum1(CInt(counterLocalFiles))
UpdateLabelText2(CStr(counterLocalFiles))
And this:
Dim counterRemoteFiles = IO.Directory.GetFiles(DestinationPath, "*.jpg", SearchOption.AllDirectories).Length
UpdateProgressBar1(CInt(counterRemoteFiles))
UpdateLabelText1(CStr(counterRemoteFiles))
And I added:
fsw1.IncludeSubdirectories = True
Now the weired Problems started: It would properly count the file in the source Directory setting label2 to the correct amount of files in all subdirectories and then start copying. It would NOT update the Progressbar though in real time. It just updated it once when it was done with the first directory and just adding the amount of files to it which it contained. After that it completly stoppedd nored the second directory and didn't add that at all to the progressbar. What am I doing wrong here? I hope my english is fine, If you have any question or If I was not clear enough, please let me know. Thank you
You don't have an event consumer that triggers your progressbar update routine - you call it once when your filesystemwatcher is instantiated.
You need to declare an event that handles the copy event and fires off your progress update code. Because Filesystemwatcher cannot monitor network drives, you may want to declare an event that fires off your progress update method when the counterRemoteFiles count increments.
Turns out I just made a mistake with correctly putting the
fsw1.IncludeSubdirectories = True
I was setting it to true in the Form Editor instead of doing it in the code. Once i actually put that in the code after initialising the fsw, it would work just fine

" A Sharing Violation occured" error when editing images in Paint using VB.NET

I have written a program in VB.NET to monitor file changes to recent saved screenshots taken from the tool.
I have a custom FileSystemWatcher class written (shared by someone on the internet,just customized) and have an instance invoked in my program.
The basic issue or objective is that when i capture a screen area using my program, I want it to immediately copy it over to clipboard. There are times when I would want to edit the captured image, in which case any editing made and saved, after saving the edited image must automatically be copied over to clipboard.
I use the below code to copy the image over to clipboard
'Subroutine to Copy the captured screenshot
'Added 15/09/2014
Sub CopyImageCapture(ByVal ImgPath)
Dim ThreadA As Thread
ThreadA = New Thread(AddressOf Me.MyAsyncTask)
'Setting ApartmentState.STA as this is needed for Clipboard related functionalities
ThreadA.SetApartmentState(ApartmentState.STA)
ThreadA.Start(ImgPath)
End Sub
'Threading to handle the Clipboard copy function
'Copy the screenshot to Clipboard
'Added 15/09/2014
Private Sub MyAsyncTask(ByVal ImgPath)
Clipboard.Clear()
Clipboard.SetImage(ImgPath)
End Sub
And when i choose to edit the image, the below code takes care to monitor the file changes
Sub MonitorFileChange(ByVal FolderPath, ByVal ItemName)
Try
Dim sFolder As String
Dim sFile As String
sFolder = FolderPath
sFile = ItemName
If IO.Directory.Exists(sFolder) Then
objWatcher.FolderToMonitor = sFolder
objWatcher.FileToMonitor = sFile
'objWatcher.NotifyFilter = (NotifyFilters.FileName Or NotifyFilters.Size)
objWatcher.StartWatch()
Else
MessageBox.Show("Folder does not exist!")
End If
Catch ex As Exception
MsgBox("Encountered an exception in MonitorFileChange subroutine. Details - " + ex.Message)
End Try
End Sub
'Subrountine to capture FileChanged events (esp. when captured image is edited in Paint and Saved)
'Works in sync with custom class 'clsFSW' for this purpose.
'ADDED: 15/09/2014
Private Sub objWatcher_FileChanged(ByVal FullPath As String) Handles objWatcher.FileChanged
'Try
Dim lastWriteTime As DateTime
lastWriteTime = File.GetLastWriteTime(FullPath)
Debug.Print(lastWriteTime)
If (lastWriteTime <> lastRead) Then
objWatcher.EnableRaisingEvents = False
'QuickCopy for changes files. BUG FIX
If (QuickSaveToolStripMenuItem.Checked) Then
Debug.Print("File Changed: " & FullPath & vbCrLf)
Dim tempI As System.Drawing.Bitmap = New System.Drawing.Bitmap(FullPath)
Dim tempI2 As System.Drawing.Bitmap = New System.Drawing.Bitmap(tempI, tempI.Width, tempI.Height)
CopyImageCapture(tempI2)
tempI.Dispose()
End If
lastRead = lastWriteTime
End If
'Catch ex As Exception
' MsgBox("Encountered an exception in objWatcher_FileChanged subrountine. Details - " + ex.Message)
' 'Finally
' 'objWatcher.EnableRaisingEvents = True
'End Try
End Sub
The problem is sometimes when I open the captured image and make quick saves or press save a couple of times real quick I get a "A Sharing violation occured" error
Can anyone help resolve the above issue? Which part of the code or logic is causing this to happen?
Also, if you check the above snippet, sometimes (havent seen any particular pattern) but the catch block in objWatcher_FileChanged is triggered and the error is "Parameter not found"
Can someone please help into this too?
Thanks in advance! Please let me know if any info more is required.
EDIT: Please note, the sharing violation error seems invoked from the Paint application itself and not my program, but why does it happen randomly, is a mystery to me. Is there nay loophole in the logic? Any alternative logic to what I want to achieve?
Try disposing tempI2. Windows may be locking the file used with tempI, and keeping it locked since it is assigned to tempI2. If so, it may remain locked until tempI2 is disposed.

Print to XPS without a Save As dialog

How can I save an xps file by printing to a virtual printer without using the Save File As dialog? When I call the print method, a dialog automatically pops up asking the user to specify the file name and path. This only works when creating brand new files; it throws an error 'you do not have permission to write to that file...' if I attempt to overwrite an existing file. Anyways, I want the user to be able to specify the file name in my own dialog, not the one that is autamatically called by the printDocument's Print method.
Public Event PrintPage As System.Drawing.Printing.PrintPageEventHandler
Private WithEvents Doc As New Printing.PrintDocument
Public Sub SaveXPSFile()
Doc.PrinterSettings.PrinterName = "Microsoft XPS Document Writer"
Doc.PrinterSettings.PrintFileName = "C:\Users\POConnell\Documents\t.xps"
Doc.Print()
Doc.Dispose()
End Sub
Private Sub PrintDocument1_PrintPage(ByVal sender As Object, ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles Doc.PrintPage
'drawing commands go here
End sub
It's a couple of months late, but here we go.
2 questions, two answers.
Question 1:
How can I save an xps file by printing to a virtual printer without using the Save File As dialog?
Answer 1: You were close. I think you're looking for
Doc.DefaultPageSettings.PrinterSettings.PrintToFile = True
Doc.DefaultPageSettings.PrinterSettings.PrintFileName = "C:\Users\POConnell\Documents\t.xps"
Here is my implementation:
(Legal paper size, landscape mode)
Using prn As New PrintDocument
With prn
.PrinterSettings.PrinterName = "Microsoft XPS Document Writer"
AddHandler .PrintPage, _
AddressOf Me.PrintPageHandler
.DefaultPageSettings.Landscape = landscape
.DefaultPageSettings.PaperSize = New PaperSize("Legal", 850, 1400)
If My.Computer.FileSystem.FileExists("C:\temp\Log.oxps") Then My.Computer.FileSystem.DeleteFile("C:\temp\Log.oxps")
.DefaultPageSettings.PrinterSettings.PrintToFile = True
.DefaultPageSettings.PrinterSettings.PrintFileName = "C:\temp\Log.oxps"
.Print()
RemoveHandler .PrintPage, _
AddressOf Me.PrintPageHandler
End With
End Using
As you can see, I use the oxps file format, but it should still work just the same for you.
Question 2: it throws an error 'you do not have permission to write to that file...' if I attempt to overwrite an existing file.
Answer 2: Check if the file already exists prior to printing the file, and delete it if it does. Of course it will fail attempting to create a file that already exists.
For some reason using My.Computer.FileSystem.DeleteFile is faster than the traditional Kill() and System.IO.File.Delete, which both require the thread to sleep for ~1-200ms prior to recreating the file, or else a different access denied error will occur.
Hopefully this helps someone in the future!

Clicking on a button to display .CHM help file in VB.NET

I want to display a .CHM help file when clicking on a button in VB.NET. Could anyone show me code how to do this?
Private Sub cmdHelp_Click(ByVal sender As System.Objects, Byval e As System.EventArgs)Handles cmdHelp.Click
'Please help provide some code
End Sub
The .NET API offers the Help class in the System.Windows.Forms namespace. Some examples:
Help.ShowHelp(ParentForm, "HelpFile.chm", HelpNavigator.TableofContents, Nothing)
Help.ShowHelp(ParentForm, "HelpFile.chm", HelpNavigator.Index, Nothing)
Help.ShowHelp(ParentForm, "HelpFile.chm", HelpNavigator.Topic, "Page.html")
Help.ShowHelp(ParentForm, "HelpFile.chm", HelpNavigator.TopicId, 123)
Help.ShowHelp(ParentForm, "HelpFile.chm", HelpNavigator.Keyword, "Keyword")
Doing a Process.Start with a verb of open does the trick:
Module Module1
Sub Main()
Dim p As New Process()
Dim psi As New ProcessStartInfo("path to my CHM file")
psi.Verb = "open"
p.StartInfo = psi
p.Start()
Console.ReadKey()
End Sub
End Module
Note that .chm files are heavily restricted by the OS from about WinXP SP3 (SP2?) onwards - they are considered to be a reasonble security risk, so you can't open them directly from a network or remote location. You will need to code accordingly, and expect exceptions when trying to open them.
on Button click event write this code
Dim RetVal
RetVal = Shell("hh.exe " & App.HelpFile, vbNormalFocus)
Where hh.exe is any name App.Helpfile is your chm file name
You can also use HH.EXE to display a specified topic.
In the example code
replace [topicid] with the real topic id
and replace [yourhelpfile.chm] with the full path and name of your .chm file
If a return value is required
Dim RetVal As Integer = Shell("HH.EXE -mapid [topicid] ms-its:[yourhelpfile.chm]", AppWinStyle.NormalFocus)
otherwise just this
Shell("HH.EXE -mapid [topicid] ms-its:[yourhelpfile.chm]", AppWinStyle.NormalFocus)