"sameer" wrote:

> Hi guys, thanks in advance.
>
> trying to implement some multithreading here :
> VS 2003
> VB.net winforms
>
>
> I have a dropdown on a form which has list of vendors, when the user selects
> a vendor from this dropdown, a new thread is created which calls a webservice
> and the webservice returns the list of cities the vendor is in and this data
> is set as the datasource of the city dropdown on the same screen. The thread
> takes 4-5 seconds to do all this and all this Works like a charm, by the time
> the user some to the city dropdown , it already has the list of cities the
> user has selected .
>
> Now what i want to do is when the user selects mutiple values from the
> Source dropdown and if there is already a thread created from the user
> selection of the previous value (I.e within this 4-5 sec time preriod), i
> want to suspend the old thread and then start a new thread which gets the
> cities for the new vendor the user has selected and below is the code that i
> have. But the problem is when user selects multiple values from the vendor
> dropdown in the 4-5 second time period, the thread takes forever, what is
> happening here, is it that all the thread that were started at queyed even if
> i am suspending it or what how can i stop this from happening, i.e when the
> user selects a vendor then i want to suspend any previous thread which was
> getting the list of cities for the previous vendor and get the thread started
> with the new vaendor selection. Could  the problem be due to the webserivce
> that the thread creates? please suggest
> Waiting for a suggestion.
>
>
> Below is the code that i am running.
>
> Creating the thread when the user selects a new vendor from the dropdown :
>
> Private function Vendorchanged()
>              Try
>
>    
>                 'Checking to suspend any old thread which might still be acttive from
> previous selection
>                             If Not thread_refreshcontact Is Nothing AndAlso
> thread_refreshcontact.IsAlive = True Then
>
>                                 thread_refreshcontact.Suspend()
>
>                             End If
>
>                             'Beging to re-initialized the thread
>                             thread_refreshcontact = Nothing
>                             thread_refreshcontact = New
> Threading.Thread(AddressOf RefreshCity)
>                             thread_refreshcontact.Name = "vendorcity"
>                             thread_refreshcontact.IsBackground = True
>
>
>                            
>                             thread_refreshcontact.Start()
>                            
>
>                         Catch ex As Exception
>                             MsgBox(ex.ToString)
>                         End Try
>
> End function
>
>
> 'Function being called by the thread above
> Private Sub RefreshCity()
>
>         Dim custid As Int32 = 0
>         Dim Dr As DataRow
>         Dim vendorid As Int32 = 0
>
>         Try
>
>     DtCity = <CAll the webserivce which returns the datatable with the cities>
>
>
>         Catch ex As Exception
>
>             MsgBox(ex.ToString)
>         End Try
>
> End Sub
>
> Sameer

"Dennis" wrote:

> Are you sure you want to get the cities on a different thread..it seems that
> that is the critical path execution and you would want to wait until you have
> the cities listed in the listbox anyway?
> --
> Dennis in Houston
>
>
> "sameer" wrote:
>
> > Hi guys, thanks in advance.
> >
> > trying to implement some multithreading here :
> > VS 2003
> > VB.net winforms
> >
> >
> > I have a dropdown on a form which has list of vendors, when the user selects
> > a vendor from this dropdown, a new thread is created which calls a webservice
> > and the webservice returns the list of cities the vendor is in and this data
> > is set as the datasource of the city dropdown on the same screen. The thread
> > takes 4-5 seconds to do all this and all this Works like a charm, by the time
> > the user some to the city dropdown , it already has the list of cities the
> > user has selected .
> >
> > Now what i want to do is when the user selects mutiple values from the
> > Source dropdown and if there is already a thread created from the user
> > selection of the previous value (I.e within this 4-5 sec time preriod), i
> > want to suspend the old thread and then start a new thread which gets the
> > cities for the new vendor the user has selected and below is the code that i
> > have. But the problem is when user selects multiple values from the vendor
> > dropdown in the 4-5 second time period, the thread takes forever, what is
> > happening here, is it that all the thread that were started at queyed even if
> > i am suspending it or what how can i stop this from happening, i.e when the
> > user selects a vendor then i want to suspend any previous thread which was
> > getting the list of cities for the previous vendor and get the thread started
> > with the new vaendor selection. Could  the problem be due to the webserivce
> > that the thread creates? please suggest
> > Waiting for a suggestion.
> >
> >
> > Below is the code that i am running.
> >
> > Creating the thread when the user selects a new vendor from the dropdown :
> >
> > Private function Vendorchanged()
> >              Try
> >
> >    
> >                 'Checking to suspend any old thread which might still be acttive from
> > previous selection
> >                             If Not thread_refreshcontact Is Nothing AndAlso
> > thread_refreshcontact.IsAlive = True Then
> >
> >                                 thread_refreshcontact.Suspend()
> >
> >                             End If
> >
> >                             'Beging to re-initialized the thread
> >                             thread_refreshcontact = Nothing
> >                             thread_refreshcontact = New
> > Threading.Thread(AddressOf RefreshCity)
> >                             thread_refreshcontact.Name = "vendorcity"
> >                             thread_refreshcontact.IsBackground = True
> >
> >
> >                            
> >                             thread_refreshcontact.Start()
> >                            
> >
> >                         Catch ex As Exception
> >                             MsgBox(ex.ToString)
> >                         End Try
> >
> > End function
> >
> >
> > 'Function being called by the thread above
> > Private Sub RefreshCity()
> >
> >         Dim custid As Int32 = 0
> >         Dim Dr As DataRow
> >         Dim vendorid As Int32 = 0
> >
> >         Try
> >
> >     DtCity = <CAll the webserivce which returns the datatable with the cities>
> >
> >
> >         Catch ex As Exception
> >
> >             MsgBox(ex.ToString)
> >         End Try
> >
> > End Sub
> >
> > Sameer