Passing Parameters using Invoke in multi-threaded app

[Phillip Taylor]

I'm having a problem with this code. I can't really understand why it
won't work if, for example, I pass in a linked list of 0 records.

Public Sub ConversionUpdateComplete(ByRef records As LinkedList(Of
ListViewItem))
If (Me.InvokeRequired) Then
Dim method As New MigrationCompleteEventHandler(AddressOf
ConversionUpdateComplete)
Me.Invoke(method, New Object() {records})
Else

lvUpdateSuggestions.Items.Clear()

For Each l As ListViewItem In records
lvUpdateSuggestions.Items.Add(l)
Next

lvUpdateSuggestions.View = True

pbConverting.Visible = False
lblConversionWait.Visible = False
lblSuggestionNotice.Visible = True
btnNext.Enabled = True
End If
End Sub

[Spam Catcher]

Phillip Taylor <Ph*****************@gmail.comwrote in
news:11*********************@g12g2000prg.googlegro ups.com:

I'm having a problem with this code. I can't really understand why it
won't work if, for example, I pass in a linked list of 0 records.

In anycase, what is happening in your app?

You should use BeginInvoke instead. Invoke may deadlock your app under
load.

Public Sub ConversionUpdateComplete(ByRef records As LinkedList(Of
ListViewItem))
If (Me.InvokeRequired) Then
Dim method As New MigrationCompleteEventHandler(AddressOf
ConversionUpdateComplete)
Me.Invoke(method, New Object() {records})
Else

lvUpdateSuggestions.Items.Clear()

For Each l As ListViewItem In records
lvUpdateSuggestions.Items.Add(l)
Next

lvUpdateSuggestions.View = True

pbConverting.Visible = False
lblConversionWait.Visible = False
lblSuggestionNotice.Visible = True
btnNext.Enabled = True
End If
End Sub

[Armin Zingler]

"Phillip Taylor" <Ph*****************@gmail.comschrieb

I'm having a problem with this code. I can't really understand why
it won't work if, for example, I pass in a linked list of 0 records.

What does "won't work" mean? The code looks ok (although I don't know why
the arg is declared ByRef).

Public Sub ConversionUpdateComplete(ByRef records As
LinkedList(Of ListViewItem))
If (Me.InvokeRequired) Then
Dim method As New MigrationCompleteEventHandler(AddressOf
ConversionUpdateComplete)
Me.Invoke(method, New Object() {records})
Else

lvUpdateSuggestions.Items.Clear()

For Each l As ListViewItem In records
lvUpdateSuggestions.Items.Add(l)
Next

lvUpdateSuggestions.View = True

pbConverting.Visible = False
lblConversionWait.Visible = False
lblSuggestionNotice.Visible = True
btnNext.Enabled = True
End If
End Sub

Armin

[Michel Posseth [MCP]]

I have seern lots of strange behavior of .net apps when used byref
parameters , as i also do not see the point why it should be passed byref in
this case , i recomend you to declare the parameter byval and try again it
might / or might not solve your problem :-)
Regards

Michel Posseth
"Armin Zingler" <az*******@freenet.deschreef in bericht
news:%2****************@TK2MSFTNGP02.phx.gbl...

"Phillip Taylor" <Ph*****************@gmail.comschrieb

>I'm having a problem with this code. I can't really understand why
it won't work if, for example, I pass in a linked list of 0 records.

What does "won't work" mean? The code looks ok (although I don't know why
the arg is declared ByRef).

> Public Sub ConversionUpdateComplete(ByRef records As
LinkedList(Of ListViewItem))
If (Me.InvokeRequired) Then
Dim method As New MigrationCompleteEventHandler(AddressOf
ConversionUpdateComplete)
Me.Invoke(method, New Object() {records})
Else

lvUpdateSuggestions.Items.Clear()

For Each l As ListViewItem In records
lvUpdateSuggestions.Items.Add(l)
Next

lvUpdateSuggestions.View = True

pbConverting.Visible = False
lblConversionWait.Visible = False
lblSuggestionNotice.Visible = True
btnNext.Enabled = True
End If
End Sub

Armin