More VB 2005 Express dilemmas .
I need a way of finding out whether a file exists (i know this bit), but it needs to keep on checking from Form1.Load to kill.

I don't like using timers.

Is it possible?

You can start with telling us what programming language you're programming. If you're programming with the Win32 API, you should use CreateFileEx.
If you're using a dotNet based language, I think you can find it easily at  Google.

vikke

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Originally posted by vikke
you should use CreateFileEx.

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Yeah, my bad, I meant CreateFile.

And make sure you call GetLastError directly after your CreateFile call, otherwise you could get: "Error: Operation Successfully Completed".

vikke

If you're using .NET, this may be of some interest.
http://msdn2.microsoft.com/en-us/library/system.io.file.exists.aspx

I think he already knows how to check if a file exists, but he wants to know a way to keep continually checking untill the program exits. Without using Timers

I think the best way is to check if the file exists the first time and after that register a handle to watch filechanges in that directory.

EDIT: Watching filechanges is possible with FileSystemWatcher in .NET

If you open a file with CreateFile, the file cannot get deleted, only renamed.
If you don't want it to get removed, that's probably the best way.

vikke

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Originally posted by vikke
You can start with telling us what programming language you're programming.

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quote:

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Originally posted by me
More VB 2005 Express dilemmas

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quote:

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Originally posted by Ryxpia
The program it needs to be in opens and sends a file, to be exact "PP5022.mi4" to a dynamic drive label, and all the while there is a Label that will either say "Theme not loaded. Please load theme." or "Theme loaded". Is there something you can put in Form1.Load that will just keep on checking?

If you don't get me, here's the diagram as I see it:

Private Sub Form1.Load [all the rest of that args stuff]
If Form1.Active Then
Keep.On.Checking.If.File.Exists(tillKill)
Using My.Computer.FileSystem.FileExists("E:\PP5022.mi4")

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Never tried this in .NET but I suppose the classic, create a file pointer and check if its null should work perfectly fine
ie handle to file is null, file doesn't exist, else it does

Not exactly what I wanted... (or maybe it was...? I'm not too flashy with VB)

anyway, I've set the path in Form1.Load, now all I need is to link up the FileSystemWatcher with _exist_ (the label) somehow, and keep it checking whether PP5022.mi4 exists or not.

So how is that to be done?

I made a little example:

code:

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Public Class Form1

    Private File As String = "C:\DataFile.dat"
    Private mywatcher As New IO.FileSystemWatcher 'Create new instance of FileSystemWatcher

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        'Check the first time if the File Exists
        If System.IO.File.Exists(File) Then
            mywatcher.Path = File 'Specify Path to File or Directory. Which ever you need
            mywatcher.IncludeSubdirectories = False
            mywatcher.NotifyFilter = IO.NotifyFilters.DirectoryName Or IO.NotifyFilters.FileName Or IO.NotifyFilters.LastWrite Or IO.NotifyFilters.Security

            AddHandler mywatcher.Deleted, AddressOf OnDeleted  'Use intellisense to see what others are open to you

            mywatcher.EnableRaisingEvents = True     'Start the process
        End If
    End Sub

    Private Sub OnDeleted(ByVal sender As Object, ByVal e As System.IO.FileSystemEventArgs)
        If e.FullPath = File And e.ChangeType = IO.WatcherChangeTypes.Deleted Then
            'FILE HAS BEEN REMOVED!!
        End If
    End Sub

End Class

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WDZ implement auto code coloring

quote:

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Originally posted by Ryxpia

quote:

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Originally posted by vikke
You can start with telling us what programming language you're programming.

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quote:

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Originally posted by me
More VB 2005 Express dilemmas

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The program it needs to be in opens and sends a file, to be exact "PP5022.mi4" to a dynamic drive label, and all the while there is a Label that will either say "Theme not loaded. Please load theme." or "Theme loaded". Is there something you can put in Form1.Load that will just keep on checking?

If you don't get me, here's the diagram as I see it:

Private Sub Form1.Load [all the rest of that args stuff]
If Form1.Active Then
Keep.On.Checking.If.File.Exists(tillKill)
Using My.Computer.FileSystem.FileExists("E:\PP5022.mi4")

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Ezra, will your code work as I want:

-App is executed
-Code starts
-Person enters and sends a file
-Code sees this and changes label to appropriate text
-App is killed

Hope this is a bit clearer.

EDIT: It seems to work. How do I make an event for -Code sees this and changes label to appropriate text ?

make an event and pop in this code:

code:

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objname.Text = "whatever"
' blah blah blah

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