Help Thread pooling ???

Dear all,

I have a function that I need to run in a thread due to the fact that it can
takes long time to execute according to the amount of data to collect.
This function is also populating a treeview control whne collected data gets
finished.

In order to achieve this I have used the following code :
System.Threading.ThreadPool.QueueUserWorkItem(New
System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))

Then my function definition is as follow :

===>>
private sub GetListOfReelsFromRemoteDB
m_objRemoteHist = New Remote(m_sRemoteDbPath)

m_objRemoteHist.Read()
Dim sParam(0) As Object

sParam(0) = m_objRemoteHist
tLogView.Invoke(AddReels, sParam)
Me.Cursor = Cursors.Default
end sub
<<===

The Read routine, collect data froma remote database
When Read return, it populates a tree view control with a delagate object by
using the Invoke.

Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
frees my whole application and gets "no responding status". I guess there
shuld be something wrong with the thread queue process but do not know why
and how to solve it

Does anyone could help ?

regards
serge

The necessary call to Invoke causes the update of the treeview to execute on
the thread of your form. This means that the UI will be unresponsive while
the treeview is being populated because the main thread is busy.

If you want the UI to be more responsive you might want to try changing the
code so that Invoke is called once for each item instead of once for all
items. This will give the main thread a little extra time to update the UI
inbetween the calls to Invoke. You may have to add some code to handle the
case where the user closes the form while the tree is being populated.

HTH, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

Dear all,

I have a function that I need to run in a thread due to the fact that it can
takes long time to execute according to the amount of data to collect.
This function is also populating a treeview control whne collected data gets
finished.

In order to achieve this I have used the following code :
System.Threading.ThreadPool.QueueUserWorkItem(New
System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))

Then my function definition is as follow :

===>>
private sub GetListOfReelsFromRemoteDB
m_objRemoteHist = New Remote(m_sRemoteDbPath)

m_objRemoteHist.Read()
Dim sParam(0) As Object

sParam(0) = m_objRemoteHist
tLogView.Invoke(AddReels, sParam)
Me.Cursor = Cursors.Default
end sub
<<===

The Read routine, collect data froma remote database
When Read return, it populates a tree view control with a delagate object by
using the Invoke.

Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
frees my whole application and gets "no responding status". I guess there
shuld be something wrong with the thread queue process but do not know why
and how to solve it

Does anyone could help ?

regards
serge

The necessary call to Invoke causes the update of the treeview to execute on
the thread of your form. This means that the UI will be unresponsive while
the treeview is being populated because the main thread is busy.

If you want the UI to be more responsive you might want to try changing the
code so that Invoke is called once for each item instead of once for all
items. This will give the main thread a little extra time to update the UI
inbetween the calls to Invoke. You may have to add some code to handle the
case where the user closes the form while the tree is being populated.

HTH, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

Dear all,

I have a function that I need to run in a thread due to the fact that it can
takes long time to execute according to the amount of data to collect.
This function is also populating a treeview control whne collected data gets
finished.

In order to achieve this I have used the following code :
System.Threading.ThreadPool.QueueUserWorkItem(New
System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))

Then my function definition is as follow :

===>>
private sub GetListOfReelsFromRemoteDB
m_objRemoteHist = New Remote(m_sRemoteDbPath)

m_objRemoteHist.Read()
Dim sParam(0) As Object

sParam(0) = m_objRemoteHist
tLogView.Invoke(AddReels, sParam)
Me.Cursor = Cursors.Default
end sub
<<===

The Read routine, collect data froma remote database
When Read return, it populates a tree view control with a delagate object by
using the Invoke.

Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
frees my whole application and gets "no responding status". I guess there
shuld be something wrong with the thread queue process but do not know why
and how to solve it

Does anyone could help ?

regards
serge

I just try your suggestion use the invoke at each node but it freeze
immediatly for ever.

It freeze as soon as the Invoke line start to be executed
I am stuck indeed out of idea.
"Jakob Christensen" wrote:

The necessary call to Invoke causes the update of the treeview to execute on
the thread of your form. This means that the UI will be unresponsive while
the treeview is being populated because the main thread is busy.

If you want the UI to be more responsive you might want to try changing the
code so that Invoke is called once for each item instead of once for all
items. This will give the main thread a little extra time to update the UI
inbetween the calls to Invoke. You may have to add some code to handle the
case where the user closes the form while the tree is being populated.

HTH, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

Dear all,

I have a function that I need to run in a thread due to the fact that it can
takes long time to execute according to the amount of data to collect.
This function is also populating a treeview control whne collected data gets
finished.

In order to achieve this I have used the following code :
System.Threading.ThreadPool.QueueUserWorkItem(New
System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))

Then my function definition is as follow :

===>>
private sub GetListOfReelsFromRemoteDB
m_objRemoteHist = New Remote(m_sRemoteDbPath)

m_objRemoteHist.Read()
Dim sParam(0) As Object

sParam(0) = m_objRemoteHist
tLogView.Invoke(AddReels, sParam)
Me.Cursor = Cursors.Default
end sub
<<===

The Read routine, collect data froma remote database
When Read return, it populates a tree view control with a delagate object by
using the Invoke.

Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
frees my whole application and gets "no responding status". I guess there
shuld be something wrong with the thread queue process but do not know why
and how to solve it

Does anyone could help ?

regards
serge

I wrote a small sample for you. Can you get this working (you need to create
a form with a button and a treeview first)?

Private Sub AddToTreeView(ByVal text As String)
Me.TreeView1.Nodes.Add(text)
End Sub

Delegate Sub AddToTreeViewDelegate(ByVal text As String)

Private Sub ReadData(ByVal state As Object)
Dim callback As New AddToTreeViewDelegate(AddressOf AddToTreeView)
Dim i As Integer
For i = 0 To 100000
Me.Invoke(callback, New Object() {i.ToString()})
Next
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ReadData))
End Sub

Regards, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

I just try your suggestion use the invoke at each node but it freeze
immediatly for ever.

It freeze as soon as the Invoke line start to be executed
I am stuck indeed out of idea.
"Jakob Christensen" wrote:

The necessary call to Invoke causes the update of the treeview to execute on
the thread of your form. This means that the UI will be unresponsive while
the treeview is being populated because the main thread is busy.

If you want the UI to be more responsive you might want to try changing the
code so that Invoke is called once for each item instead of once for all
items. This will give the main thread a little extra time to update the UI
inbetween the calls to Invoke. You may have to add some code to handle the
case where the user closes the form while the tree is being populated.

HTH, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

> Dear all,
>
> I have a function that I need to run in a thread due to the fact that it can
> takes long time to execute according to the amount of data to collect.
> This function is also populating a treeview control whne collected data gets
> finished.
>
> In order to achieve this I have used the following code :
> System.Threading.ThreadPool.QueueUserWorkItem(New
> System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))
>
> Then my function definition is as follow :
>
> ===>>
> private sub GetListOfReelsFromRemoteDB
> m_objRemoteHist = New Remote(m_sRemoteDbPath)
>
> m_objRemoteHist.Read()
> Dim sParam(0) As Object
>
> sParam(0) = m_objRemoteHist
> tLogView.Invoke(AddReels, sParam)
> Me.Cursor = Cursors.Default
> end sub
> <<===
>
> The Read routine, collect data froma remote database
> When Read return, it populates a tree view control with a delagate object by
> using the Invoke.
>
> Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
> frees my whole application and gets "no responding status". I guess there
> shuld be something wrong with the thread queue process but do not know why
> and how to solve it
>
> Does anyone could help ?
>
> regards
> serge

Yes I am able to make it work...

What is the difference between the way I am doing it and your sample then ?
I could not found any.

my treeView is ona main form, the procedure I called in the thread pool is
collecting data froma a remote database (no problem here) and I am populating
the tree when all data from databased gets collected.

Or should I remove the Invoke outside of the threadpool ?

Thanks for your help
Regards
"Jakob Christensen" wrote:

I wrote a small sample for you. Can you get this working (you need to create
a form with a button and a treeview first)?

Private Sub AddToTreeView(ByVal text As String)
Me.TreeView1.Nodes.Add(text)
End Sub

Delegate Sub AddToTreeViewDelegate(ByVal text As String)

Private Sub ReadData(ByVal state As Object)
Dim callback As New AddToTreeViewDelegate(AddressOf AddToTreeView)
Dim i As Integer
For i = 0 To 100000
Me.Invoke(callback, New Object() {i.ToString()})
Next
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ReadData))
End Sub

Regards, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

I just try your suggestion use the invoke at each node but it freeze
immediatly for ever.

It freeze as soon as the Invoke line start to be executed
I am stuck indeed out of idea.
"Jakob Christensen" wrote:

> The necessary call to Invoke causes the update of the treeview to execute on
> the thread of your form. This means that the UI will be unresponsive while
> the treeview is being populated because the main thread is busy.
>
> If you want the UI to be more responsive you might want to try changing the
> code so that Invoke is called once for each item instead of once for all
> items. This will give the main thread a little extra time to update the UI
> inbetween the calls to Invoke. You may have to add some code to handle the
> case where the user closes the form while the tree is being populated.
>
> HTH, Jakob.
> --
> http://www.dotninjas.dk
> http://www.powerbytes.dk
>
>
> "serge calderara" wrote:
>
> > Dear all,
> >
> > I have a function that I need to run in a thread due to the fact that it can
> > takes long time to execute according to the amount of data to collect.
> > This function is also populating a treeview control whne collected data gets
> > finished.
> >
> > In order to achieve this I have used the following code :
> > System.Threading.ThreadPool.QueueUserWorkItem(New
> > System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))
> >
> > Then my function definition is as follow :
> >
> > ===>>
> > private sub GetListOfReelsFromRemoteDB
> > m_objRemoteHist = New Remote(m_sRemoteDbPath)
> >
> > m_objRemoteHist.Read()
> > Dim sParam(0) As Object
> >
> > sParam(0) = m_objRemoteHist
> > tLogView.Invoke(AddReels, sParam)
> > Me.Cursor = Cursors.Default
> > end sub
> > <<===
> >
> > The Read routine, collect data froma remote database
> > When Read return, it populates a tree view control with a delagate object by
> > using the Invoke.
> >
> > Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
> > frees my whole application and gets "no responding status". I guess there
> > shuld be something wrong with the thread queue process but do not know why
> > and how to solve it
> >
> > Does anyone could help ?
> >
> > regards
> > serge

I wrote a small sample for you. Can you get this working (you need to create
a form with a button and a treeview first)?

Private Sub AddToTreeView(ByVal text As String)
Me.TreeView1.Nodes.Add(text)
End Sub

Delegate Sub AddToTreeViewDelegate(ByVal text As String)

Private Sub ReadData(ByVal state As Object)
Dim callback As New AddToTreeViewDelegate(AddressOf AddToTreeView)
Dim i As Integer
For i = 0 To 100000
Me.Invoke(callback, New Object() {i.ToString()})
Next
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ReadData))
End Sub

Regards, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

I just try your suggestion use the invoke at each node but it freeze
immediatly for ever.

It freeze as soon as the Invoke line start to be executed
I am stuck indeed out of idea.
"Jakob Christensen" wrote:

The necessary call to Invoke causes the update of the treeview to execute on
the thread of your form. This means that the UI will be unresponsive while
the treeview is being populated because the main thread is busy.

If you want the UI to be more responsive you might want to try changing the
code so that Invoke is called once for each item instead of once for all
items. This will give the main thread a little extra time to update the UI
inbetween the calls to Invoke. You may have to add some code to handle the
case where the user closes the form while the tree is being populated.

HTH, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

> Dear all,
>
> I have a function that I need to run in a thread due to the fact that it can
> takes long time to execute according to the amount of data to collect.
> This function is also populating a treeview control whne collected data gets
> finished.
>
> In order to achieve this I have used the following code :
> System.Threading.ThreadPool.QueueUserWorkItem(New
> System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))
>
> Then my function definition is as follow :
>
> ===>>
> private sub GetListOfReelsFromRemoteDB
> m_objRemoteHist = New Remote(m_sRemoteDbPath)
>
> m_objRemoteHist.Read()
> Dim sParam(0) As Object
>
> sParam(0) = m_objRemoteHist
> tLogView.Invoke(AddReels, sParam)
> Me.Cursor = Cursors.Default
> end sub
> <<===
>
> The Read routine, collect data froma remote database
> When Read return, it populates a tree view control with a delagate object by
> using the Invoke.
>
> Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
> frees my whole application and gets "no responding status". I guess there
> shuld be something wrong with the thread queue process but do not know why
> and how to solve it
>
> Does anyone could help ?
>
> regards
> serge

Try posting your code (the essential parts) and I will have a look at it.

Regards, Jakob.

--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

Yes I am able to make it work...

What is the difference between the way I am doing it and your sample then ?
I could not found any.

my treeView is ona main form, the procedure I called in the thread pool is
collecting data froma a remote database (no problem here) and I am populating
the tree when all data from databased gets collected.

Or should I remove the Invoke outside of the threadpool ?

Thanks for your help
Regards
"Jakob Christensen" wrote:

I wrote a small sample for you. Can you get this working (you need to create
a form with a button and a treeview first)?

Private Sub AddToTreeView(ByVal text As String)
Me.TreeView1.Nodes.Add(text)
End Sub

Delegate Sub AddToTreeViewDelegate(ByVal text As String)

Private Sub ReadData(ByVal state As Object)
Dim callback As New AddToTreeViewDelegate(AddressOf AddToTreeView)
Dim i As Integer
For i = 0 To 100000
Me.Invoke(callback, New Object() {i.ToString()})
Next
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ReadData))
End Sub

Regards, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

> I just try your suggestion use the invoke at each node but it freeze
> immediatly for ever.
>
> It freeze as soon as the Invoke line start to be executed
> I am stuck indeed out of idea.
>
>
> "Jakob Christensen" wrote:
>
> > The necessary call to Invoke causes the update of the treeview to execute on
> > the thread of your form. This means that the UI will be unresponsive while
> > the treeview is being populated because the main thread is busy.
> >
> > If you want the UI to be more responsive you might want to try changing the
> > code so that Invoke is called once for each item instead of once for all
> > items. This will give the main thread a little extra time to update the UI
> > inbetween the calls to Invoke. You may have to add some code to handle the
> > case where the user closes the form while the tree is being populated.
> >
> > HTH, Jakob.
> > --
> > http://www.dotninjas.dk
> > http://www.powerbytes.dk
> >
> >
> > "serge calderara" wrote:
> >
> > > Dear all,
> > >
> > > I have a function that I need to run in a thread due to the fact that it can
> > > takes long time to execute according to the amount of data to collect.
> > > This function is also populating a treeview control whne collected data gets
> > > finished.
> > >
> > > In order to achieve this I have used the following code :
> > > System.Threading.ThreadPool.QueueUserWorkItem(New
> > > System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))
> > >
> > > Then my function definition is as follow :
> > >
> > > ===>>
> > > private sub GetListOfReelsFromRemoteDB
> > > m_objRemoteHist = New Remote(m_sRemoteDbPath)
> > >
> > > m_objRemoteHist.Read()
> > > Dim sParam(0) As Object
> > >
> > > sParam(0) = m_objRemoteHist
> > > tLogView.Invoke(AddReels, sParam)
> > > Me.Cursor = Cursors.Default
> > > end sub
> > > <<===
> > >
> > > The Read routine, collect data froma remote database
> > > When Read return, it populates a tree view control with a delagate object by
> > > using the Invoke.
> > >
> > > Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
> > > frees my whole application and gets "no responding status". I guess there
> > > shuld be something wrong with the thread queue process but do not know why
> > > and how to solve it
> > >
> > > Does anyone could help ?
> > >
> > > regards
> > > serge

Try posting your code (the essential parts) and I will have a look at it.

Regards, Jakob.

--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

Yes I am able to make it work...

What is the difference between the way I am doing it and your sample then ?
I could not found any.

my treeView is ona main form, the procedure I called in the thread pool is
collecting data froma a remote database (no problem here) and I am populating
the tree when all data from databased gets collected.

Or should I remove the Invoke outside of the threadpool ?

Thanks for your help
Regards
"Jakob Christensen" wrote:

I wrote a small sample for you. Can you get this working (you need to create
a form with a button and a treeview first)?

Private Sub AddToTreeView(ByVal text As String)
Me.TreeView1.Nodes.Add(text)
End Sub

Delegate Sub AddToTreeViewDelegate(ByVal text As String)

Private Sub ReadData(ByVal state As Object)
Dim callback As New AddToTreeViewDelegate(AddressOf AddToTreeView)
Dim i As Integer
For i = 0 To 100000
Me.Invoke(callback, New Object() {i.ToString()})
Next
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ReadData))
End Sub

Regards, Jakob.
--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

> I just try your suggestion use the invoke at each node but it freeze
> immediatly for ever.
>
> It freeze as soon as the Invoke line start to be executed
> I am stuck indeed out of idea.
>
>
> "Jakob Christensen" wrote:
>
> > The necessary call to Invoke causes the update of the treeview to execute on
> > the thread of your form. This means that the UI will be unresponsive while
> > the treeview is being populated because the main thread is busy.
> >
> > If you want the UI to be more responsive you might want to try changing the
> > code so that Invoke is called once for each item instead of once for all
> > items. This will give the main thread a little extra time to update the UI
> > inbetween the calls to Invoke. You may have to add some code to handle the
> > case where the user closes the form while the tree is being populated.
> >
> > HTH, Jakob.
> > --
> > http://www.dotninjas.dk
> > http://www.powerbytes.dk
> >
> >
> > "serge calderara" wrote:
> >
> > > Dear all,
> > >
> > > I have a function that I need to run in a thread due to the fact that it can
> > > takes long time to execute according to the amount of data to collect.
> > > This function is also populating a treeview control whne collected data gets
> > > finished.
> > >
> > > In order to achieve this I have used the following code :
> > > System.Threading.ThreadPool.QueueUserWorkItem(New
> > > System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))
> > >
> > > Then my function definition is as follow :
> > >
> > > ===>>
> > > private sub GetListOfReelsFromRemoteDB
> > > m_objRemoteHist = New Remote(m_sRemoteDbPath)
> > >
> > > m_objRemoteHist.Read()
> > > Dim sParam(0) As Object
> > >
> > > sParam(0) = m_objRemoteHist
> > > tLogView.Invoke(AddReels, sParam)
> > > Me.Cursor = Cursors.Default
> > > end sub
> > > <<===
> > >
> > > The Read routine, collect data froma remote database
> > > When Read return, it populates a tree view control with a delagate object by
> > > using the Invoke.
> > >
> > > Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
> > > frees my whole application and gets "no responding status". I guess there
> > > shuld be something wrong with the thread queue process but do not know why
> > > and how to solve it
> > >
> > > Does anyone could help ?
> > >
> > > regards
> > > serge

Hi jakob, some more info about my trouble.
I have paste only the necessary code into your sample application to see if
I am able to collect and update the treview.
It works reaaly fine.

Then I keep it as it is and do exactly the same thing again from scratch
into my own aplication and same situation occurs, it freeze my all application

According to my test what I have notice is that it freeze, as long as the
Invoke try to execute as following code:

For Each m_Reel In m_objRemoteHist.ListOfReels
Param(0) = m_Reel
Me.tLogView.Invoke(callback, Param)
ProgressBar1.Value = ProgressBar1.Value + 1
Next

I have the remove everything into that callback function, so I have just the
definition and a simple msgbox message inside, it do not even jum to the
message box. For me sounds that it cannot jump to the call back routine or
paramete is badly pass, but it so strange that same sytax works fine on your
code.

I ma lost any more idea or how to debug that stuff ?

thnaks again
serge

"Jakob Christensen" wrote:

Try posting your code (the essential parts) and I will have a look at it.

Regards, Jakob.

--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

Yes I am able to make it work...

What is the difference between the way I am doing it and your sample then ?
I could not found any.

my treeView is ona main form, the procedure I called in the thread pool is
collecting data froma a remote database (no problem here) and I am populating
the tree when all data from databased gets collected.

Or should I remove the Invoke outside of the threadpool ?

Thanks for your help
Regards
"Jakob Christensen" wrote:

> I wrote a small sample for you. Can you get this working (you need to create
> a form with a button and a treeview first)?
>
> Private Sub AddToTreeView(ByVal text As String)
> Me.TreeView1.Nodes.Add(text)
> End Sub
>
> Delegate Sub AddToTreeViewDelegate(ByVal text As String)
>
> Private Sub ReadData(ByVal state As Object)
> Dim callback As New AddToTreeViewDelegate(AddressOf AddToTreeView)
> Dim i As Integer
> For i = 0 To 100000
> Me.Invoke(callback, New Object() {i.ToString()})
> Next
> End Sub
>
> Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
> System.EventArgs) Handles Button1.Click
> ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ReadData))
> End Sub
>
> Regards, Jakob.
> --
> http://www.dotninjas.dk
> http://www.powerbytes.dk
>
>
> "serge calderara" wrote:
>
> > I just try your suggestion use the invoke at each node but it freeze
> > immediatly for ever.
> >
> > It freeze as soon as the Invoke line start to be executed
> > I am stuck indeed out of idea.
> >
> >
> > "Jakob Christensen" wrote:
> >
> > > The necessary call to Invoke causes the update of the treeview to execute on
> > > the thread of your form. This means that the UI will be unresponsive while
> > > the treeview is being populated because the main thread is busy.
> > >
> > > If you want the UI to be more responsive you might want to try changing the
> > > code so that Invoke is called once for each item instead of once for all
> > > items. This will give the main thread a little extra time to update the UI
> > > inbetween the calls to Invoke. You may have to add some code to handle the
> > > case where the user closes the form while the tree is being populated.
> > >
> > > HTH, Jakob.
> > > --
> > > http://www.dotninjas.dk
> > > http://www.powerbytes.dk
> > >
> > >
> > > "serge calderara" wrote:
> > >
> > > > Dear all,
> > > >
> > > > I have a function that I need to run in a thread due to the fact that it can
> > > > takes long time to execute according to the amount of data to collect.
> > > > This function is also populating a treeview control whne collected data gets
> > > > finished.
> > > >
> > > > In order to achieve this I have used the following code :
> > > > System.Threading.ThreadPool.QueueUserWorkItem(New
> > > > System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))
> > > >
> > > > Then my function definition is as follow :
> > > >
> > > > ===>>
> > > > private sub GetListOfReelsFromRemoteDB
> > > > m_objRemoteHist = New Remote(m_sRemoteDbPath)
> > > >
> > > > m_objRemoteHist.Read()
> > > > Dim sParam(0) As Object
> > > >
> > > > sParam(0) = m_objRemoteHist
> > > > tLogView.Invoke(AddReels, sParam)
> > > > Me.Cursor = Cursors.Default
> > > > end sub
> > > > <<===
> > > >
> > > > The Read routine, collect data froma remote database
> > > > When Read return, it populates a tree view control with a delagate object by
> > > > using the Invoke.
> > > >
> > > > Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
> > > > frees my whole application and gets "no responding status". I guess there
> > > > shuld be something wrong with the thread queue process but do not know why
> > > > and how to solve it
> > > >
> > > > Does anyone could help ?
> > > >
> > > > regards
> > > > serge

Hey Serge,

The following two lines taken from your sample looks wrong:

Me.tLogView.Invoke(callback, Param)
ProgressBar1.Value = ProgressBar1.Value + 1

The call to ProgressBar1 is not legal since you are not allowed to call any
controls from another thread. So you have to update the progress bar using
Invoke. What is tLogView? Is that your Windows form?

Regards, Jakob.

--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

Hi jakob, some more info about my trouble.
I have paste only the necessary code into your sample application to see if
I am able to collect and update the treview.
It works reaaly fine.

Then I keep it as it is and do exactly the same thing again from scratch
into my own aplication and same situation occurs, it freeze my all application

According to my test what I have notice is that it freeze, as long as the
Invoke try to execute as following code:

For Each m_Reel In m_objRemoteHist.ListOfReels
Param(0) = m_Reel
Me.tLogView.Invoke(callback, Param)
ProgressBar1.Value = ProgressBar1.Value + 1
Next

I have the remove everything into that callback function, so I have just the
definition and a simple msgbox message inside, it do not even jum to the
message box. For me sounds that it cannot jump to the call back routine or
paramete is badly pass, but it so strange that same sytax works fine on your
code.

I ma lost any more idea or how to debug that stuff ?

thnaks again
serge

"Jakob Christensen" wrote:

Try posting your code (the essential parts) and I will have a look at it.

Regards, Jakob.

--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

> Yes I am able to make it work...
>
> What is the difference between the way I am doing it and your sample then ?
> I could not found any.
>
> my treeView is ona main form, the procedure I called in the thread pool is
> collecting data froma a remote database (no problem here) and I am populating
> the tree when all data from databased gets collected.
>
> Or should I remove the Invoke outside of the threadpool ?
>
> Thanks for your help
> Regards
>
>
> "Jakob Christensen" wrote:
>
> > I wrote a small sample for you. Can you get this working (you need to create
> > a form with a button and a treeview first)?
> >
> > Private Sub AddToTreeView(ByVal text As String)
> > Me.TreeView1.Nodes.Add(text)
> > End Sub
> >
> > Delegate Sub AddToTreeViewDelegate(ByVal text As String)
> >
> > Private Sub ReadData(ByVal state As Object)
> > Dim callback As New AddToTreeViewDelegate(AddressOf AddToTreeView)
> > Dim i As Integer
> > For i = 0 To 100000
> > Me.Invoke(callback, New Object() {i.ToString()})
> > Next
> > End Sub
> >
> > Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
> > System.EventArgs) Handles Button1.Click
> > ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ReadData))
> > End Sub
> >
> > Regards, Jakob.
> > --
> > http://www.dotninjas.dk
> > http://www.powerbytes.dk
> >
> >
> > "serge calderara" wrote:
> >
> > > I just try your suggestion use the invoke at each node but it freeze
> > > immediatly for ever.
> > >
> > > It freeze as soon as the Invoke line start to be executed
> > > I am stuck indeed out of idea.
> > >
> > >
> > > "Jakob Christensen" wrote:
> > >
> > > > The necessary call to Invoke causes the update of the treeview to execute on
> > > > the thread of your form. This means that the UI will be unresponsive while
> > > > the treeview is being populated because the main thread is busy.
> > > >
> > > > If you want the UI to be more responsive you might want to try changing the
> > > > code so that Invoke is called once for each item instead of once for all
> > > > items. This will give the main thread a little extra time to update the UI
> > > > inbetween the calls to Invoke. You may have to add some code to handle the
> > > > case where the user closes the form while the tree is being populated.
> > > >
> > > > HTH, Jakob.
> > > > --
> > > > http://www.dotninjas.dk
> > > > http://www.powerbytes.dk
> > > >
> > > >
> > > > "serge calderara" wrote:
> > > >
> > > > > Dear all,
> > > > >
> > > > > I have a function that I need to run in a thread due to the fact that it can
> > > > > takes long time to execute according to the amount of data to collect.
> > > > > This function is also populating a treeview control whne collected data gets
> > > > > finished.
> > > > >
> > > > > In order to achieve this I have used the following code :
> > > > > System.Threading.ThreadPool.QueueUserWorkItem(New
> > > > > System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))
> > > > >
> > > > > Then my function definition is as follow :
> > > > >
> > > > > ===>>
> > > > > private sub GetListOfReelsFromRemoteDB
> > > > > m_objRemoteHist = New Remote(m_sRemoteDbPath)
> > > > >
> > > > > m_objRemoteHist.Read()
> > > > > Dim sParam(0) As Object
> > > > >
> > > > > sParam(0) = m_objRemoteHist
> > > > > tLogView.Invoke(AddReels, sParam)
> > > > > Me.Cursor = Cursors.Default
> > > > > end sub
> > > > > <<===
> > > > >
> > > > > The Read routine, collect data froma remote database
> > > > > When Read return, it populates a tree view control with a delagate object by
> > > > > using the Invoke.
> > > > >
> > > > > Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
> > > > > frees my whole application and gets "no responding status". I guess there
> > > > > shuld be something wrong with the thread queue process but do not know why
> > > > > and how to solve it
> > > > >
> > > > > Does anyone could help ?
> > > > >
> > > > > regards
> > > > > serge

Hey Serge,

The following two lines taken from your sample looks wrong:

Me.tLogView.Invoke(callback, Param)
ProgressBar1.Value = ProgressBar1.Value + 1

The call to ProgressBar1 is not legal since you are not allowed to call any
controls from another thread. So you have to update the progress bar using
Invoke. What is tLogView? Is that your Windows form?

Regards, Jakob.

--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

Hi jakob, some more info about my trouble.
I have paste only the necessary code into your sample application to see if
I am able to collect and update the treview.
It works reaaly fine.

Then I keep it as it is and do exactly the same thing again from scratch
into my own aplication and same situation occurs, it freeze my all application

According to my test what I have notice is that it freeze, as long as the
Invoke try to execute as following code:

For Each m_Reel In m_objRemoteHist.ListOfReels
Param(0) = m_Reel
Me.tLogView.Invoke(callback, Param)
ProgressBar1.Value = ProgressBar1.Value + 1
Next

I have the remove everything into that callback function, so I have just the
definition and a simple msgbox message inside, it do not even jum to the
message box. For me sounds that it cannot jump to the call back routine or
paramete is badly pass, but it so strange that same sytax works fine on your
code.

I ma lost any more idea or how to debug that stuff ?

thnaks again
serge

"Jakob Christensen" wrote:

Try posting your code (the essential parts) and I will have a look at it.

Regards, Jakob.

--
http://www.dotninjas.dk
http://www.powerbytes.dk
"serge calderara" wrote:

> Yes I am able to make it work...
>
> What is the difference between the way I am doing it and your sample then ?
> I could not found any.
>
> my treeView is ona main form, the procedure I called in the thread pool is
> collecting data froma a remote database (no problem here) and I am populating
> the tree when all data from databased gets collected.
>
> Or should I remove the Invoke outside of the threadpool ?
>
> Thanks for your help
> Regards
>
>
> "Jakob Christensen" wrote:
>
> > I wrote a small sample for you. Can you get this working (you need to create
> > a form with a button and a treeview first)?
> >
> > Private Sub AddToTreeView(ByVal text As String)
> > Me.TreeView1.Nodes.Add(text)
> > End Sub
> >
> > Delegate Sub AddToTreeViewDelegate(ByVal text As String)
> >
> > Private Sub ReadData(ByVal state As Object)
> > Dim callback As New AddToTreeViewDelegate(AddressOf AddToTreeView)
> > Dim i As Integer
> > For i = 0 To 100000
> > Me.Invoke(callback, New Object() {i.ToString()})
> > Next
> > End Sub
> >
> > Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
> > System.EventArgs) Handles Button1.Click
> > ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ReadData))
> > End Sub
> >
> > Regards, Jakob.
> > --
> > http://www.dotninjas.dk
> > http://www.powerbytes.dk
> >
> >
> > "serge calderara" wrote:
> >
> > > I just try your suggestion use the invoke at each node but it freeze
> > > immediatly for ever.
> > >
> > > It freeze as soon as the Invoke line start to be executed
> > > I am stuck indeed out of idea.
> > >
> > >
> > > "Jakob Christensen" wrote:
> > >
> > > > The necessary call to Invoke causes the update of the treeview to execute on
> > > > the thread of your form. This means that the UI will be unresponsive while
> > > > the treeview is being populated because the main thread is busy.
> > > >
> > > > If you want the UI to be more responsive you might want to try changing the
> > > > code so that Invoke is called once for each item instead of once for all
> > > > items. This will give the main thread a little extra time to update the UI
> > > > inbetween the calls to Invoke. You may have to add some code to handle the
> > > > case where the user closes the form while the tree is being populated.
> > > >
> > > > HTH, Jakob.
> > > > --
> > > > http://www.dotninjas.dk
> > > > http://www.powerbytes.dk
> > > >
> > > >
> > > > "serge calderara" wrote:
> > > >
> > > > > Dear all,
> > > > >
> > > > > I have a function that I need to run in a thread due to the fact that it can
> > > > > takes long time to execute according to the amount of data to collect.
> > > > > This function is also populating a treeview control whne collected data gets
> > > > > finished.
> > > > >
> > > > > In order to achieve this I have used the following code :
> > > > > System.Threading.ThreadPool.QueueUserWorkItem(New
> > > > > System.Threading.WaitCallback(AddressOf GetListOfReelsFromRemoteDB))
> > > > >
> > > > > Then my function definition is as follow :
> > > > >
> > > > > ===>>
> > > > > private sub GetListOfReelsFromRemoteDB
> > > > > m_objRemoteHist = New Remote(m_sRemoteDbPath)
> > > > >
> > > > > m_objRemoteHist.Read()
> > > > > Dim sParam(0) As Object
> > > > >
> > > > > sParam(0) = m_objRemoteHist
> > > > > tLogView.Invoke(AddReels, sParam)
> > > > > Me.Cursor = Cursors.Default
> > > > > end sub
> > > > > <<===
> > > > >
> > > > > The Read routine, collect data froma remote database
> > > > > When Read return, it populates a tree view control with a delagate object by
> > > > > using the Invoke.
> > > > >
> > > > > Problem I have is that when tLogView.Invoke(AddReels,sparam) execute, it
> > > > > frees my whole application and gets "no responding status". I guess there
> > > > > shuld be something wrong with the thread queue process but do not know why
> > > > > and how to solve it
> > > > >
> > > > > Does anyone could help ?
> > > > >
> > > > > regards
> > > > > serge