Form crashes when uploading file on background thread - vb.net

Question

I am trying to upload a file using a thread. I have placed a simple file upload control and a button on a page.The code looks like this-
Protected Sub btnUpload_Click(ByVal sender As Object,
ByVal e As EventArgs) Handles btnUpload.Click
Dim timeStart As TimeSpan = Nothing
Dim timeEnd As TimeSpan = Nothing
Dim timeDiff As TimeSpan = Nothing
Dim ex As Exception = Nothing
Dim FileNameWithoutExtension As String = String.Empty
Try
Dim objTh As Thread = Nothing
objTh = New Thread(AddressOf SaveFileByBuffering)
timeStart = DateTime.Now.TimeOfDay
objTh.IsBackground = True
FileNameWithoutExtension = System.IO.Path.GetFileName(FldUploadThreading.FileName)
objTh.Start("New_" + FileNameWithoutExtension)
objTh.Name = "ARAThreadFileBuffer"
objTh.Join()
timeEnd = DateTime.Now.TimeOfDay
timeDiff = timeEnd - timeStart
Catch exThAbort As ThreadAbortException
ex = exThAbort
Catch exTh As ThreadStartException
ex = exTh
Catch exCommon As Exception
ex = exCommon
End Try
End Sub
Method to be called using thread:
Public Function SaveFileByBuffering(ByVal lstrFilePath As String)
Dim bufferSize As Integer = 512
Dim buffer As Byte() = New Byte(bufferSize - 1) {}
Dim pathUrl As String = ConfigurationManager.AppSettings("strFilePath").ToString()
Dim uploadObj As UploadDetail = New UploadDetail()
uploadObj.IsReady = True
uploadObj.FileName = lstrFilePath
uploadObj.ContentLength = Me.FldUploadThreading.PostedFile.ContentLength
Me.Session("UploadXDetail") = uploadObj
Dim Upload As UploadDetail = DirectCast(Me.Session("UploadXDetail"), UploadDetail)
Dim fileName As String = Path.GetFileName(Me.FldUploadThreading.PostedFile.FileName)
Using fs As New FileStream(Path.Combine(pathUrl, lstrFilePath), FileMode.Create)
While Upload.UploadedLength < Upload.ContentLength
Dim bytes As Integer = Me.FldUploadThreading.PostedFile.InputStream.Read(buffer, 0, bufferSize)
fs.Write(buffer, 0, bytes)
Upload.UploadedLength += bytes
End While
End Using
End Function
There are two issues:
When someone clicks on the same button simultaneously the thread behavior works in a different way, some time page crashes.
When this process I have tested on multi-user environment with 60 users and file size is 25 mb each user the page crashed.
I have to use .NET 3.5 so I cannot use the advanced version of file upload in 2010 or later.
Error : 1-File uploding is more than 15 minutes but still in progress 2- Internet explorer cannot explore the page -Diagnose Internet problems 3- some user get login probem to the server on which the site has hosted

Answer 1

The course I usually take in .NET is to use ThreadPool.QueueUserWorkItem
If you do this with anonymous lambdas, I find it makes the syntax and life rather nice. You can do something like this:
btnUpload.Enabled = False
ThreadPool.QueueUserWorkItem(Sub()
SaveFileByBuffering(FldUploadThreading.FileName)
RaiseEvent EnableButton
End Sub)
With this event handler:
Public Sub EnableButton() Handles EnableButton
If Me.InvokeRequired Then
Me.BeginInvoke(Sub() EnableButton())
Else
btnUpload.Enabled = True
EndIf
EndSub
My .NET is rusty and I don't have a compiler anywhere, but doing something like this should handle most of your issues.