How to interupt code execution in a method

[Frank]

I need to make a program that will import data from a
text file into a database.
I have already designed the user interface, and I am
coding a class to open the file and handle the data. Now
an object of the class will be initialised and I will
call the data procedure in it though a method, and pass
it ref parameter for update of a counter in the user
interface, when the user press a start button. All that
seems fine.

However, if the user needs to stop the operation, I need
to somehow be able to break the import. I guess that I
could have a stop button, which could call another method
in the object, that would set a private cancel variable
for the object to the value true. The running import
procedure could then check on the cancel variable.
However, would that ever work, since the first method
that is doing the import, is not complete yet?

Is this a situation where another thread needs to be
used? I have not been working with threads before, so if
this is the case, perhaps someone can explain a bit, and
direct me to some articles in the help system that will
clarify this.
With kind regards,

Frank

[Frank]

Hi Crirus,

There is no attachment the posting. I don't think you can
attach to newsgroup postings.
Perhaps you can include a link to a webpage instead.
Regards,

Frank

-----Original Message-----
Hi!
Check out this attach...!
Regards,

Crirus

[Crirus]

Yes, there is I use outlook express and I can see my zip attached ....
"Frank" <an*******@discussions.microsoft.com> wrote in message
news:0a****************************@phx.gbl...

Hi Crirus,

There is no attachment the posting. I don't think you can
attach to newsgroup postings.
Perhaps you can include a link to a webpage instead.
Regards,

Frank

-----Original Message-----
Hi!
Check out this attach...!
Regards,

Crirus

[Frank]

Hi Crisus,

Ok, I won't argue with you there :-).
However, I access the newsgroups through the MSDN website
(http://msdn.microsoft.com/newsgroups/) and I think they
strip all attachments for security reasons. Also, I
access the newsgroups from more than one computer, so
prefer to read them this way).

Perhaps you could be so kind as to direct me to a
webpage, or perhaps there is no such?
With kind regards,

Frank

-----Original Message-----
Yes, there is I use outlook express and I can see my zip attached ....

"Frank" <an*******@discussions.microsoft.com> wrote in messagenews:0a****************************@phx.gbl...

Hi Crirus,

There is no attachment the posting. I don't think you can attach to newsgroup postings.
Perhaps you can include a link to a webpage instead.
Regards,

Frank

>-----Original Message-----
>Hi!
>Check out this attach...!
>
>
>Regards,
>
>Crirus
>
>
>

.

[Fergus Cooney]

Hi Frank,

I use OE too, so the attachment's fine.
Here's Crirus's code.

Regards,
Fergus

ps. This uses a TextBox for demonstation which is fine here, but is not the
recommended way to interact with UI Controls. For that you need to call
oControl.BeginInvoke.

===========================================
<ThreadWorker.vb>
Imports System.Threading

Public Class ThreadWorker

' members...
Public TextBox As TextBox
Private _thread As Thread

' Start - this method is the entry-point for the thread...
Private Sub Start()

' just set some text on the textbox...
TextBox.Text = "Hello, world from thread " & _
_thread.Name & " #" & _
Thread.CurrentThread.GetHashCode() & "!"
End Sub

' SpinUp - this method is called by the main application thread...
Public Sub SpinUp()

' create a thread start object that refers to our worker...
Dim threadStart As ThreadStart
threadStart = New ThreadStart(AddressOf Me.Start)

' now, create the thread object and start it...
_thread = New Thread(threadStart)
_thread.Name = "Worker"
_thread.Start()

End Sub

End Class
</ThreadWorker.vb>

<Form1.vb>
Imports System.Threading

Add a TextBox - txtResult
Add a Button - btnStartThread

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

Thread.CurrentThread.Name = "Main"
Me.Text &= " - Thread Main #" & Thread.CurrentThread.GetHashCode
End Sub

Private Sub btnStartThread_Click(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles btnStartThread.Click

' create a new worker...
Dim worker As New ThreadWorker()
worker.TextBox = txtResult

' spin up the thread...
worker.SpinUp()
End Sub
</Form1.vb>

Thanks,

Frank

-----Original Message-----
Hi Frank,

I use OE too, so the attachment's fine.
Here's Crirus's code.

Regards,
Fergus

ps. This uses a TextBox for demonstation which is fine here, but is not therecommended way to interact with UI Controls. For that you need to calloControl.BeginInvoke.

===========================================
<ThreadWorker.vb>
Imports System.Threading

Public Class ThreadWorker

' members...
Public TextBox As TextBox
Private _thread As Thread

' Start - this method is the entry-point for the thread... Private Sub Start()

' just set some text on the textbox...
TextBox.Text = "Hello, world from thread " & _
_thread.Name & " #" & _
Thread.CurrentThread.GetHashCode() & "!"
End Sub

' SpinUp - this method is called by the main application thread... Public Sub SpinUp()

' create a thread start object that refers to our worker... Dim threadStart As ThreadStart
threadStart = New ThreadStart(AddressOf Me.Start)

' now, create the thread object and start it...
_thread = New Thread(threadStart)
_thread.Name = "Worker"
_thread.Start()

End Sub

End Class
</ThreadWorker.vb>

<Form1.vb>
Imports System.Threading

Add a TextBox - txtResult
Add a Button - btnStartThread

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

Thread.CurrentThread.Name = "Main"
Me.Text &= " - Thread Main #" & Thread.CurrentThread.GetHashCode End Sub

Private Sub btnStartThread_Click(ByVal sender As Object, _ ByVal e As System.EventArgs) Handles btnStartThread.Click
' create a new worker...
Dim worker As New ThreadWorker()
worker.TextBox = txtResult

' spin up the thread...
worker.SpinUp()
End Sub
</Form1.vb>
.

[Crirus]

Thanks Fergus...

There is a post where you dont have a helpfull post? :)

Crirus
"Fergus Cooney" <fi******@tesco.net> wrote in message
news:eu**************@TK2MSFTNGP12.phx.gbl...

Hi Frank,

I use OE too, so the attachment's fine.
Here's Crirus's code.

Regards,
Fergus

ps. This uses a TextBox for demonstation which is fine here, but is not the recommended way to interact with UI Controls. For that you need to call
oControl.BeginInvoke.

===========================================
<ThreadWorker.vb>
Imports System.Threading

Public Class ThreadWorker

' members...
Public TextBox As TextBox
Private _thread As Thread

' Start - this method is the entry-point for the thread...
Private Sub Start()

' just set some text on the textbox...
TextBox.Text = "Hello, world from thread " & _
_thread.Name & " #" & _
Thread.CurrentThread.GetHashCode() & "!"
End Sub

' SpinUp - this method is called by the main application thread...
Public Sub SpinUp()

' create a thread start object that refers to our worker...
Dim threadStart As ThreadStart
threadStart = New ThreadStart(AddressOf Me.Start)

' now, create the thread object and start it...
_thread = New Thread(threadStart)
_thread.Name = "Worker"
_thread.Start()

End Sub

End Class
</ThreadWorker.vb>

<Form1.vb>
Imports System.Threading

Add a TextBox - txtResult
Add a Button - btnStartThread

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

Thread.CurrentThread.Name = "Main"
Me.Text &= " - Thread Main #" & Thread.CurrentThread.GetHashCode
End Sub

Private Sub btnStartThread_Click(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles btnStartThread.Click

' create a new worker...
Dim worker As New ThreadWorker()
worker.TextBox = txtResult

' spin up the thread...
worker.SpinUp()
End Sub
</Form1.vb>

[Fergus Cooney]

Hi Crirus,

ROFL. Fingers in many pies, but in some I'm the bad guy!! I'm not all
sweetness and light, much to the occasional annoyance of a couple of people
and permanent (perhaps not, that's a long time) distaste of a couple of
others.

But more friends than otherwise. ;-))

Regards,
Fergus