"Nathan Sokalski" <njsokalski@hotmail.com> wrote in message
news:uK8sGmZZGHA.4836@TK2MSFTNGP05.phx.gbl...
>I have a directory on my site that I keep a bunch of text files in (this
>directory is "/poetry/poems/"). The Application keeps the first line of
>each of these files in an HttpApplicationState variable as a SortedList.
>When I add or modify a file in this directory, I want to delete this
>HttpApplicationState variable. I tried to do this using the following lines
>of code in Global.asax.vb:
>
>
> Private WithEvents poemfilewatcher As New
> IO.FileSystemWatcher(HttpContext.Current.Server.MapPath("/poetry/poems/"))
>
> Private Sub PoemDirModified(ByVal sender As Object, ByVal e As
> System.IO.FileSystemEventArgs) Handles poemfilewatcher.Changed,
> poemfilewatcher.Created, poemfilewatcher.Deleted
> HttpContext.Current.Application.Lock()
> HttpContext.Current.Application.Remove("poemlist")
> HttpContext.Current.Application.UnLock()
> End Sub
>
> Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
> poemfilewatcher.IncludeSubdirectories = True
> poemfilewatcher.EnableRaisingEvents = True
> End Sub
>
>
> The Function that I use to return this SortedList, whether it is stored in
> an HttpApplicationState variable or not, is the following, which is also
> located in Global.asax.vb:
>
>
> Public Shared Function GetPoems() As SortedList 'Key=Title, Value=File
> If HttpContext.Current.Application("poemlist") Is Nothing Then
> Dim Poems As New SortedList(New CaseInsensitiveComparer)
> Dim poemfiles As String() =
> System.IO.Directory.GetFiles(HttpContext.Current.Server.MapPath("/poetry/poems/"))
> Dim poemstreamreader As System.IO.StreamReader
> Poems.Capacity = 50 'Not quite 50 poems, so call Poems.TrimToSize()
> before caching
> For Each poemfile As String In poemfiles
> poemstreamreader = System.IO.File.OpenText(poemfile)
> Poems.Add(poemstreamreader.ReadLine(), poemfile)
> poemstreamreader.Close()
> Next
> Poems.TrimToSize()
> HttpContext.Current.Application.Lock()
> HttpContext.Current.Application.Add("poemlist", Poems)
> HttpContext.Current.Application.UnLock()
> Return Poems
> Else
> Return CType(HttpContext.Current.Application("poemlist"),
> SortedList)
> End If
> End Function
>
>
> However, when I add, delete, or modify a file in the directory it does not
> seem to delete the HttpApplicationState variable. Am I forgetting to do
> something? Am I doing something wrong? Any help would be appreciated, or
> possibly an example that mentions all the necessary & required steps.
> Thank you to anyone who can give me any help with this.
> --
> Nathan Sokalski
> njsokalski@hotmail.com
> http://www.nathansokalski.com/
>

> The responses that you and Peter have given me

"Nathan Sokalski" <njsokalski@hotmail.com> wrote in message
news:ug9WfjaZGHA.4424@TK2MSFTNGP05.phx.gbl...
> The responses that you and Peter have given me both seem like very good
> advice, but like I have said, I don't really have any experience using
> threads in VB.NET. This fact combined with what you have said about the
> event needing to be fired while processing a request when used with
ASP.NET
> is making it kind of hard for me to figure out what to do about figuring
out
> a solution. Do you have any suggestions/ideas/recommended sites that could
> help? Thanks.
> --
> Nathan Sokalski
> njsokalski@hotmail.com
> http://www.nathansokalski.com/
>
> "bruce barker (sqlwork.com)" <b_r_u_c_e_removeunderscores@sqlwork.com>
wrote
> in message news:%23WbQrAaZGHA.4752@TK2MSFTNGP02.phx.gbl...
> > you have a couple issues.
> >
> > 1) you need to dedicate a thread to the filewatcher. currently you are
> > using the first request thread. if no request come for a couple a
seconds.
> > request threads come from a pool. if not reused, the thread is killed.
> >
> > 2) you are using HttpContext.Current. this will not be valid unless the
> > the event is fired while processing a request.
> >
> > you should start a background thread, pass it a reference to the
context,
> > and process the event.
> >
> > -- bruce (sqlwork.com)
> >
> >
> > "Nathan Sokalski" <njsokalski@hotmail.com> wrote in message
> > news:uK8sGmZZGHA.4836@TK2MSFTNGP05.phx.gbl...
> >>I have a directory on my site that I keep a bunch of text files in (this
> >>directory is "/poetry/poems/"). The Application keeps the first line of
> >>each of these files in an HttpApplicationState variable as a SortedList.
> >>When I add or modify a file in this directory, I want to delete this
> >>HttpApplicationState variable. I tried to do this using the following
> >>lines of code in Global.asax.vb:
> >>
> >>
> >> Private WithEvents poemfilewatcher As New
> >>
IO.FileSystemWatcher(HttpContext.Current.Server.MapPath("/poetry/poems/"))
> >>
> >> Private Sub PoemDirModified(ByVal sender As Object, ByVal e As
> >> System.IO.FileSystemEventArgs) Handles poemfilewatcher.Changed,
> >> poemfilewatcher.Created, poemfilewatcher.Deleted
> >> HttpContext.Current.Application.Lock()
> >> HttpContext.Current.Application.Remove("poemlist")
> >> HttpContext.Current.Application.UnLock()
> >> End Sub
> >>
> >> Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
> >> poemfilewatcher.IncludeSubdirectories = True
> >> poemfilewatcher.EnableRaisingEvents = True
> >> End Sub
> >>
> >>
> >> The Function that I use to return this SortedList, whether it is stored
> >> in an HttpApplicationState variable or not, is the following, which is
> >> also located in Global.asax.vb:
> >>
> >>
> >> Public Shared Function GetPoems() As SortedList 'Key=Title, Value=File
> >> If HttpContext.Current.Application("poemlist") Is Nothing Then
> >> Dim Poems As New SortedList(New CaseInsensitiveComparer)
> >> Dim poemfiles As String() =
> >>

> >> Dim poemstreamreader As System.IO.StreamReader
> >> Poems.Capacity = 50 'Not quite 50 poems, so call
> >> Poems.TrimToSize() before caching
> >> For Each poemfile As String In poemfiles
> >> poemstreamreader = System.IO.File.OpenText(poemfile)
> >> Poems.Add(poemstreamreader.ReadLine(), poemfile)
> >> poemstreamreader.Close()
> >> Next
> >> Poems.TrimToSize()
> >> HttpContext.Current.Application.Lock()
> >> HttpContext.Current.Application.Add("poemlist", Poems)
> >> HttpContext.Current.Application.UnLock()
> >> Return Poems
> >> Else
> >> Return CType(HttpContext.Current.Application("poemlist"),
> >> SortedList)
> >> End If
> >> End Function
> >>
> >>
> >> However, when I add, delete, or modify a file in the directory it does
> >> not seem to delete the HttpApplicationState variable. Am I forgetting
to
> >> do something? Am I doing something wrong? Any help would be
appreciated,
> >> or possibly an example that mentions all the necessary & required
steps.
> >> Thank you to anyone who can give me any help with this.
> >> --
> >> Nathan Sokalski
> >> njsokalski@hotmail.com
> >> http://www.nathansokalski.com/
> >>
> >
> >
>
>

"bruce barker (sqlwork.com)" <b_r_u_c_e_removeunderscores@sqlwork.com> wrote
in message news:%23WbQrAaZGHA.4752@TK2MSFTNGP02.phx.gbl...
> you have a couple issues.
>
> 1) you need to dedicate a thread to the filewatcher. currently you are
> using the first request thread. if no request come for a couple a seconds.
> request threads come from a pool. if not reused, the thread is killed.
>
> 2) you are using HttpContext.Current. this will not be valid unless the
> the event is fired while processing a request.
>
> you should start a background thread, pass it a reference to the context,
> and process the event.
>
> -- bruce (sqlwork.com)
>
>
> "Nathan Sokalski" <njsokalski@hotmail.com> wrote in message
> news:uK8sGmZZGHA.4836@TK2MSFTNGP05.phx.gbl...
>>I have a directory on my site that I keep a bunch of text files in (this
>>directory is "/poetry/poems/"). The Application keeps the first line of
>>each of these files in an HttpApplicationState variable as a SortedList.
>>When I add or modify a file in this directory, I want to delete this
>>HttpApplicationState variable. I tried to do this using the following
>>lines of code in Global.asax.vb:
>>
>>
>> Private WithEvents poemfilewatcher As New
>> IO.FileSystemWatcher(HttpContext.Current.Server.MapPath("/poetry/poems/"))
>>
>> Private Sub PoemDirModified(ByVal sender As Object, ByVal e As
>> System.IO.FileSystemEventArgs) Handles poemfilewatcher.Changed,
>> poemfilewatcher.Created, poemfilewatcher.Deleted
>> HttpContext.Current.Application.Lock()
>> HttpContext.Current.Application.Remove("poemlist")
>> HttpContext.Current.Application.UnLock()
>> End Sub
>>
>> Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
>> poemfilewatcher.IncludeSubdirectories = True
>> poemfilewatcher.EnableRaisingEvents = True
>> End Sub
>>
>>
>> The Function that I use to return this SortedList, whether it is stored
>> in an HttpApplicationState variable or not, is the following, which is
>> also located in Global.asax.vb:
>>
>>
>> Public Shared Function GetPoems() As SortedList 'Key=Title, Value=File
>> If HttpContext.Current.Application("poemlist") Is Nothing Then
>> Dim Poems As New SortedList(New CaseInsensitiveComparer)
>> Dim poemfiles As String() =
>> System.IO.Directory.GetFiles(HttpContext.Current.Server.MapPath("/poetry/poems/"))
>> Dim poemstreamreader As System.IO.StreamReader
>> Poems.Capacity = 50 'Not quite 50 poems, so call
>> Poems.TrimToSize() before caching
>> For Each poemfile As String In poemfiles
>> poemstreamreader = System.IO.File.OpenText(poemfile)
>> Poems.Add(poemstreamreader.ReadLine(), poemfile)
>> poemstreamreader.Close()
>> Next
>> Poems.TrimToSize()
>> HttpContext.Current.Application.Lock()
>> HttpContext.Current.Application.Add("poemlist", Poems)
>> HttpContext.Current.Application.UnLock()
>> Return Poems
>> Else
>> Return CType(HttpContext.Current.Application("poemlist"),
>> SortedList)
>> End If
>> End Function
>>
>>
>> However, when I add, delete, or modify a file in the directory it does
>> not seem to delete the HttpApplicationState variable. Am I forgetting to
>> do something? Am I doing something wrong? Any help would be appreciated,
>> or possibly an example that mentions all the necessary & required steps.
>> Thank you to anyone who can give me any help with this.
>> --
>> Nathan Sokalski
>> njsokalski@hotmail.com
>> http://www.nathansokalski.com/
>>
>
>