StrataFrame Forum » .NET Forums » General .NET Discussion » Few questions about threads and waitwindow

Few questions about threads and waitwindow

Robin J Giltner — Mon, 02 Jul 2007 14:50:45 GMT

I need to invoke the vb threading gods of the forum. I'm very new to delegates and cross form method calls etc.

I have a main form with a class level WaitWindow that methods on the form can show, hide, update whatever. This form makes several calls to a class that performs a lot of data manipulation. Some of these take a long time, so I decided updating the WaitWindow would be nice to let the user know something is going on.

My declaration of the WaitWindow on the form.

[codesnippet]

Public WithEvents loWaitWindow As New MicroFour.StrataFrame.Messaging.WaitWindow

[/codesnippet]

Here is my method to Update that WaitWindow

[codesnippet]

Public Sub UpdateWaitWindow(ByVal lcMessage As String)

'-- Update the Wait Window Message

Me.loWaitwindow.Message = lcMessage

End Sub

[/codesnippet]

And on my class that does the data manipulation, I added this delegate

[codesnippet]

Public Delegate Sub UpdateWaitWindow(ByVal lcMessage As String)

[/codesnippet]

And I added a Reference to the main Form to call UpdateWaitWindow on

[codesnippet]

Public Shared loForm As frmProjectMain = CType(Application.OpenForms("frmProjectMain"), frmProjectMain)

[/codesnippet]

Now should I be able to call this UpdateWaitWindow by simply ?

[codesnippet]

loForm.Invoke(New UpdateWaitWindow(AddressOf loForm.UpdateWaitWindow), "new message")

[/codesnippet]

RE: Few questions about threads and waitwindow

Robin J Giltner — Mon, 02 Jul 2007 14:50:45 GMT

Great. Thanks Ben.

Robin Giltner

RE: Few questions about threads and waitwindow

StrataFrame Team — Mon, 02 Jul 2007 08:46:51 GMT

Yes, that's how you would do it. Now, when you're calling the Invoke of the ISynchronizeInvoke interface (on any Control object, like a form), you have to make sure that the control's thread is not busy. Meaning, if you try to Invoke() from the main thread back to the main thread, you'll enter deadlock... the CLR waits until the main thread is not busy before calling the invoked method.

RE: Few questions about threads and waitwindow

Greg McGuffey — Fri, 29 Jun 2007 11:10:11 GMT

[quote]I need to invoke the vb threading gods of the forum. [/quote]

Well, that leaves me out, even though I do own a sewing machine and I'm not afraid to use it! :P

Sorry for the unhelpful reply...it's been a hard week, it's friday, I've been up way too long and it's summer time, and silliness just bubble to the fore. :hehe:

I'll be watching the thread (er...no pun intended) to learn more about threads though!