BackGroundWorke r.ProgressChang ed "Cross-thread operation not valid" at 2nd/3th/... progress

Hi,

I'm having some weird problem using the BackGroundWorke r in an Outlook
(2003) Add-In, with VB.NET 2005:
I'm using the BackGroundWorke r to get the info of some mailitems, and
after each item I want to raise the ProgressChanged-event to update the
DataGridView.
It works fine when only one Progresschanged is fired, but at the second,
third, fopurth etc it raises everytile a 'Cross-thread operation not
valid"-exception on lmy DataGridView (dgvAdd).

Any idea what causes this problem? What am I doing wrong? What is the
problem here?

Any help our hints would be really appreciated!

Thanks a lot in advance,

Pieter
This is my code:
Me.bgwInfoOutlo ok.RunWorkerAsy nc(Me.m_colItem s)

Private Sub bgwInfoOutlook_ DoWork(ByVal sender As Object, ByVal e As
System.Componen tModel.DoWorkEv entArgs) Handles bgwInfoOutlook. DoWork
Dim col As Collection = e.Argument
AddHandler docCtrl.InfoLis tChanged, AddressOf InfoListChanged
Dim str As String = docCtrl.GetOutl ookInfo(col,
Me.m_objOutlook Folder)
e.Result = docCtrl.AddedDo cMails
End Sub

Private Sub InfoListChanged (ByVal sender As Object, ByVal e As
EventArgs)
Me.bgwInfoOutlo ok.ReportProgre ss(0)
End Sub

Private Sub bgwInfoOutlook_ ProgressChanged (ByVal sender As Object,
ByVal e As System.Componen tModel.Progress ChangedEventArg s) Handles
bgwInfoOutlook. ProgressChanged
'bind the list to the datagridview
Try
Me.dgvAdd.DataS ource = Nothing
Me.dgvAdd.DataS ource = docCtrl.InfoLis t
Catch ex As Exception
ErrorMessage(ex )
End Try
End Sub
This is the exception:

{"Cross-thread operation not valid: Control 'dgvAdd' accessed from a
thread other than the thread it was created on."}
System.InvalidO perationExcepti on: {"Cross-thread operation not valid:
Control 'dgvAdd' accessed from a thread other than the thread it was
created on."}
Data: {System.Collect ions.ListDictio naryInternal}
HelpLink: Nothing
InnerException: Nothing
Message: "Cross-thread operation not valid: Control 'dgvAdd' accessed
from a thread other than the thread it was created on."
Source: "System.Windows .Forms"
StackTrace: " at System.Windows. Forms.Control.g et_Handle()
at System.Windows. Forms.Control.g et_InternalHand le()
at System.Windows. Forms.Control.g et_CreateParams ()
at System.Windows. Forms.ScrollBar .get_CreatePara ms()
at System.Windows. Forms.VScrollBa r.get_CreatePar ams()
at System.Windows. Forms.Control.U pdateBounds(Int 32 x, Int32 y, Int32
width, Int32 height)
at System.Windows. Forms.Control.S etBoundsCore(In t32 x, Int32 y, Int32
width, Int32 height, BoundsSpecified specified)
at System.Windows. Forms.Control.S etBounds(Int32 x, Int32 y, Int32 width,
Int32 height, BoundsSpecified specified)
at System.Windows. Forms.Control.s et_Bounds(Recta ngle value)
at System.Windows. Forms.DataGridV iew.LayoutScrol lBars()
at System.Windows. Forms.DataGridV iew.ComputeLayo ut()
at System.Windows. Forms.DataGridV iew.PerformLayo utPrivate(Boole an
useRowShortcut, Boolean computeVisibleR ows, Boolean
invalidInAdjust FillingColumns, Boolean repositionEditi ngControl)
at
System.Windows. Forms.DataGridV iew.OnColumnWid thChanged(DataG ridViewColumnEv entArgs
e)
at
System.Windows. Forms.DataGridV iew.OnBandThick nessChanged(Dat aGridViewBand
dataGridViewBan d)
at System.Windows. Forms.DataGridV iewBand.set_Thi cknessInternal( Int32
value)
at System.Windows. Forms.DataGridV iew.AdjustFilli ngColumns()
at System.Windows. Forms.DataGridV iew.ComputeLayo ut()
at System.Windows. Forms.DataGridV iew.PerformLayo utPrivate(Boole an
useRowShortcut, Boolean computeVisibleR ows, Boolean
invalidInAdjust FillingColumns, Boolean repositionEditi ngControl)
at System.Windows. Forms.DataGridV iew.ResetUIStat e(Boolean
useRowShortcut, Boolean computeVisibleR ows)
at
System.Windows. Forms.DataGridV iewRowCollectio n.OnCollectionC hanged_PreNotif ication(Collect ionChangeAction
cca, Int32 rowIndex, Int32 rowCount, DataGridViewRow & dataGridViewRow ,
Boolean changeIsInserti on)
at
System.Windows. Forms.DataGridV iewRowCollectio n.OnCollectionC hanged(Collecti onChangeEventAr gs
e, Int32 rowIndex, Int32 rowCount, Boolean changeIsDeletio n, Boolean
changeIsInserti on, Boolean recreateNewRow, Point newCurrentCell)
at System.Windows. Forms.DataGridV iewRowCollectio n.InsertInterna l(Int32
rowIndex, DataGridViewRow dataGridViewRow , Boolean force)
at
System.Windows. Forms.DataGridV iew.DataGridVie wDataConnection .ProcessListCha nged(ListChange dEventArgs
e)
at
System.Windows. Forms.DataGridV iew.DataGridVie wDataConnection .currencyManage r_ListChanged(O bject
sender, ListChangedEven tArgs e)
at
System.Windows. Forms.CurrencyM anager.OnListCh anged(ListChang edEventArgs e)
at System.Windows. Forms.CurrencyM anager.List_Lis tChanged(Object sender,
ListChangedEven tArgs e)
at
System.Componen tModel.BindingL ist`1.OnListCha nged(ListChange dEventArgs e)
at System.Componen tModel.BindingL ist`1.FireListC hanged(ListChan gedType
type, Int32 index)
at System.Componen tModel.BindingL ist`1.InsertIte m(Int32 index, T item)
at System.Collecti ons.ObjectModel .Collection`1.A dd(T item)
at BaseFramework.c lsBaseList`1.Ad d(T item) in D:\NET Projecten\Code
Source Sodimex - Ghost\BaseFrame work\clsBaseLis t.vb:line 461
at DocControl.clsD ocControl.GetOu tlookInfo(Colle ction colItems, Object
oFolder, Boolean blnAttachments) in D:\NET Projecten\Code Source Sodimex -
Ghost\DocContro l\Business Layer\clsDocCon trol.vb:line 597"
TargetSite: {System.Reflect ion.RuntimeMeth odInfo}

Hi Pieter,

As far as I know, .NET 2.0 strictly prohibits any access to the user
interface from background worker threads. This wasn't allowed in .NET 1.1
either, but in that version one sometimes could get away with violating
the rule. Now you'll get the "Cross-thread operation not valid" almost for
sure.

Therefore, to do any updates to the UI properly, you should use the
Control.Invoke method to run the UI update code on the UI thread.

Hi,

I've tryed it, but it didn't work either :-/
And isn't the BackGroundWorke r designed so we shouldn't worry anymore
about those Invoke and Delegates-stuff?

This is my new code with Invoke, which doesn't work either... :-/

Private Sub bgwInfoOutlook_ ProgressChanged (ByVal sender As Object,
ByVal e As System.Componen tModel.Progress ChangedEventArg s) Handles
bgwInfoOutlook. ProgressChanged
Try
SetDataSource()
Catch ex As Exception
ErrorMessage(ex )
End Try
End Sub

Delegate Sub SetDgvCallback( )

Private Sub SetDataSource()
If Me.dgvAdd.Invok eRequired Then
Dim d As New SetDgvCallback( AddressOf SetDataSource)
Me.Invoke(d, Nothing)
Else
Me.dgvAdd.DataS ource = Nothing
Me.dgvAdd.DataS ource = docCtrl.InfoLis t
End If
End Sub

And the werit thing is: the Me.dgvAdd.Invok eRequired returns False...

"Dmytro Lapshyn [MVP]" <x-****@no-spam-please.hotpop.c om> wrote in message
news:%2******** ********@TK2MSF TNGP11.phx.gbl. ..

Hi Pieter,

As far as I know, .NET 2.0 strictly prohibits any access to the user
interface from background worker threads. This wasn't allowed in .NET 1.1
either, but in that version one sometimes could get away with violating
the rule. Now you'll get the "Cross-thread operation not valid" almost
for sure.

Therefore, to do any updates to the UI properly, you should use the
Control.Invoke method to run the UI update code on the UI thread.

Hi,

I've tryed it, but it didn't work either :-/
And isn't the BackGroundWorke r designed so we shouldn't worry anymore
about those Invoke and Delegates-stuff?

This is my new code with Invoke, which doesn't work either... :-/

Private Sub bgwInfoOutlook_ ProgressChanged (ByVal sender As Object,
ByVal e As System.Componen tModel.Progress ChangedEventArg s) Handles
bgwInfoOutlook. ProgressChanged
Try
SetDataSource()
Catch ex As Exception
ErrorMessage(ex )
End Try
End Sub

Delegate Sub SetDgvCallback( )

Private Sub SetDataSource()
If Me.dgvAdd.Invok eRequired Then
Dim d As New SetDgvCallback( AddressOf SetDataSource)
Me.Invoke(d, Nothing)
Else
Me.dgvAdd.DataS ource = Nothing
Me.dgvAdd.DataS ource = docCtrl.InfoLis t
End If
End Sub

And the werit thing is: the Me.dgvAdd.Invok eRequired returns False...

"Dmytro Lapshyn [MVP]" <x-****@no-spam-please.hotpop.c om> wrote in message
news:%2******** ********@TK2MSF TNGP11.phx.gbl. ..

Hi Pieter,

As far as I know, .NET 2.0 strictly prohibits any access to the user
interface from background worker threads. This wasn't allowed in .NET 1.1
either, but in that version one sometimes could get away with violating
the rule. Now you'll get the "Cross-thread operation not valid" almost
for sure.

Therefore, to do any updates to the UI properly, you should use the
Control.Invoke method to run the UI update code on the UI thread.

Your error message here is the same thing Dmytro said about cross-thread
UI calls. Something you are doing in DoWork (which is in a background
thread) is modifying the data grid.

The problem is more serious. You shouldn't be accessing any Outlook
objects from a background thread. It just won't work right and you'll have
all sorts of problems ranging from error messages to mysterious
OUTLOOK.EXE processes that won't shut down.

I'm afraid all of your communication with Outlook has to be done on the
same thread that calls your connect method. That would be the UI thread.
The only "async" methods you can use are the advanced search api's but I
believe even they are single-threaded much like a UI timer is.

--
Josh Einstein
Einstein Technologies
Microsoft Tablet PC MVP
Tablet Enhancements for Outlook 2.0 - Try it free for 14 days
www.tabletoutlook.com
"Pieter" <pi**********@h otmail.com> wrote in message
news:uO******** ******@TK2MSFTN GP11.phx.gbl...

Hi,

I've tryed it, but it didn't work either :-/
And isn't the BackGroundWorke r designed so we shouldn't worry anymore
about those Invoke and Delegates-stuff?

This is my new code with Invoke, which doesn't work either... :-/

Private Sub bgwInfoOutlook_ ProgressChanged (ByVal sender As Object,
ByVal e As System.Componen tModel.Progress ChangedEventArg s) Handles
bgwInfoOutlook. ProgressChanged
Try
SetDataSource()
Catch ex As Exception
ErrorMessage(ex )
End Try
End Sub

Delegate Sub SetDgvCallback( )

Private Sub SetDataSource()
If Me.dgvAdd.Invok eRequired Then
Dim d As New SetDgvCallback( AddressOf SetDataSource)
Me.Invoke(d, Nothing)
Else
Me.dgvAdd.DataS ource = Nothing
Me.dgvAdd.DataS ource = docCtrl.InfoLis t
End If
End Sub

And the werit thing is: the Me.dgvAdd.Invok eRequired returns False...

"Dmytro Lapshyn [MVP]" <x-****@no-spam-please.hotpop.c om> wrote in
message news:%2******** ********@TK2MSF TNGP11.phx.gbl. ..

Hi Pieter,

As far as I know, .NET 2.0 strictly prohibits any access to the user
interface from background worker threads. This wasn't allowed in .NET
1.1 either, but in that version one sometimes could get away with
violating the rule. Now you'll get the "Cross-thread operation not
valid" almost for sure.

Therefore, to do any updates to the UI properly, you should use the
Control.Invoke method to run the UI update code on the UI thread.

"Josh Einstein" <jo**********@h otmail.com> wrote in message
news:OW******** ******@TK2MSFTN GP14.phx.gbl...

Your error message here is the same thing Dmytro said about cross-thread
UI calls. Something you are doing in DoWork (which is in a background
thread) is modifying the data grid.

Well actually it isn't :-/
And I don't have the exception while the Dowork is performing its actions:
it happens when the ProgressChanged-event fires...

Why? COM in general (especially out-of-proc COM), and Outlook is
particular can handle cross thread/process calls just fine - all Outlook
objects are apartment threaded, so all calls will end up on the main
Outlook thread anyway.

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

"Josh Einstein" <jo**********@h otmail.com> wrote in message
news:OR******** ******@TK2MSFTN GP09.phx.gbl...

The problem is more serious. You shouldn't be accessing any Outlook
objects from a background thread. It just won't work right and you'll
have all sorts of problems ranging from error messages to mysterious
OUTLOOK.EXE processes that won't shut down.

I'm afraid all of your communication with Outlook has to be done on the
same thread that calls your connect method. That would be the UI thread.
The only "async" methods you can use are the advanced search api's but I
believe even they are single-threaded much like a UI timer is.

--
Josh Einstein
Einstein Technologies
Microsoft Tablet PC MVP
Tablet Enhancements for Outlook 2.0 - Try it free for 14 days
www.tabletoutlook.com
"Pieter" <pi**********@h otmail.com> wrote in message
news:uO******** ******@TK2MSFTN GP11.phx.gbl...

Hi,

I've tryed it, but it didn't work either :-/
And isn't the BackGroundWorke r designed so we shouldn't worry anymore
about those Invoke and Delegates-stuff?

This is my new code with Invoke, which doesn't work either... :-/

Private Sub bgwInfoOutlook_ ProgressChanged (ByVal sender As Object,
ByVal e As System.Componen tModel.Progress ChangedEventArg s) Handles
bgwInfoOutlook. ProgressChanged
Try
SetDataSource()
Catch ex As Exception
ErrorMessage(ex )
End Try
End Sub

Delegate Sub SetDgvCallback( )

Private Sub SetDataSource()
If Me.dgvAdd.Invok eRequired Then
Dim d As New SetDgvCallback( AddressOf SetDataSource)
Me.Invoke(d, Nothing)
Else
Me.dgvAdd.DataS ource = Nothing
Me.dgvAdd.DataS ource = docCtrl.InfoLis t
End If
End Sub

And the werit thing is: the Me.dgvAdd.Invok eRequired returns False...

"Dmytro Lapshyn [MVP]" <x-****@no-spam-please.hotpop.c om> wrote in
message news:%2******** ********@TK2MSF TNGP11.phx.gbl. ..
Hi Pieter,

As far as I know, .NET 2.0 strictly prohibits any access to the user
interface from background worker threads. This wasn't allowed in .NET
1.1 either, but in that version one sometimes could get away with
violating the rule. Now you'll get the "Cross-thread operation not
valid" almost for sure.

Therefore, to do any updates to the UI properly, you should use the
Control.Invoke method to run the UI update code on the UI thread.