multithread method invoke

[m.posseth]

Hello

does someone know how i can invoke a method in the underlying thread without
the usage of a window handle ??


This works perfect in a form

Me.Invoke(New MethodInvoker(A ddressOf ShowRecvdMessag e))



however in a control i receive the folowing error

"Cannot call Invoke or InvokeAsync on a control until the window handle has
been created."







the complete routine that runs on a background thread:

Private Sub Listener()

done = False

Try

While Not done

Dim iPEndPoint As IPEndPoint = Nothing

Dim bs As Byte() = client.Receive( iPEndPoint)

Dim m As IMessage = NHS.Messaging.U til.RetrieveMes sage(bs)

If Not m Is Nothing Then 'Return

message = m.MessageText

' need to use Invoke or BeginInvoke Syntax as message is on different
thread--

Me.Invoke(New MethodInvoker(A ddressOf ShowRecvdMessag e))

End If

End While

Catch e As Exception

multicastExcept ion(e)

End Try

End Sub

[rawCoder]

Re: multithread method invoke

Just a trick, see if it works,

try doing dim nHandle as integer = Me.Handle
before the invoke line

HTH
rawCoder

"m.posseth" <michelp@nohaus ystems.nl> wrote in message
news:429de7f7$0 $17462$ba620dc5 @nova.planet.nl ...[color=blue]
> Hello
>
> does someone know how i can invoke a method in the underlying thread[/color]
without[color=blue]
> the usage of a window handle ??
>
>
> This works perfect in a form
>
> Me.Invoke(New MethodInvoker(A ddressOf ShowRecvdMessag e))
>
>
>
> however in a control i receive the folowing error
>
> "Cannot call Invoke or InvokeAsync on a control until the window handle[/color]
has[color=blue]
> been created."
>
>
>
>
>
>
>
> the complete routine that runs on a background thread:
>
> Private Sub Listener()
>
> done = False
>
> Try
>
> While Not done
>
> Dim iPEndPoint As IPEndPoint = Nothing
>
> Dim bs As Byte() = client.Receive( iPEndPoint)
>
> Dim m As IMessage = NHS.Messaging.U til.RetrieveMes sage(bs)
>
> If Not m Is Nothing Then 'Return
>
> message = m.MessageText
>
> ' need to use Invoke or BeginInvoke Syntax as message is on different
> thread--
>
> Me.Invoke(New MethodInvoker(A ddressOf ShowRecvdMessag e))
>
> End If
>
> End While
>
> Catch e As Exception
>
> multicastExcept ion(e)
>
> End Try
>
> End Sub
>
>[/color]

[m.posseth]

Re: multithread method invoke

Well ,,,, after a slight conversion :-)
Dim nHandle As IntPtr = Me.Handle

This seems to work ( the error isn`t raised annymore , now see if it is
receiving data )

The problem is solved however i am still curious why it occured :-)

Private Sub Listener()

done = False

Try

While Not done

Dim iPEndPoint As IPEndPoint = Nothing

Dim bs As Byte() = client.Receive( iPEndPoint)

Dim m As IMessage = NHS.Messaging.U til.RetrieveMes sage(bs)

If Not m Is Nothing Then Return

message = m.MessageText

Dim nHandle As IntPtr = Me.Handle

' need to use Invoke or BeginInvoke Syntax as message is on different
thread--

Me.Invoke(New MethodInvoker(A ddressOf ShowRecvdMessag e))

End While

Catch e As Exception

multicastExcept ion(e)

End Try

End Sub

Thanks for helping me out

Regards

Michel Posseth






"rawCoder" <rawCoder@hotma il.com> wrote in message
news:%23hrXDLtZ FHA.3676@TK2MSF TNGP10.phx.gbl. ..[color=blue]
> Just a trick, see if it works,
>
> try doing dim nHandle as integer = Me.Handle
> before the invoke line
>
> HTH
> rawCoder
>
> "m.posseth" <michelp@nohaus ystems.nl> wrote in message
> news:429de7f7$0 $17462$ba620dc5 @nova.planet.nl ...[color=green]
>> Hello
>>
>> does someone know how i can invoke a method in the underlying thread[/color]
> without[color=green]
>> the usage of a window handle ??
>>
>>
>> This works perfect in a form
>>
>> Me.Invoke(New MethodInvoker(A ddressOf ShowRecvdMessag e))
>>
>>
>>
>> however in a control i receive the folowing error
>>
>> "Cannot call Invoke or InvokeAsync on a control until the window handle[/color]
> has[color=green]
>> been created."
>>
>>
>>
>>
>>
>>
>>
>> the complete routine that runs on a background thread:
>>
>> Private Sub Listener()
>>
>> done = False
>>
>> Try
>>
>> While Not done
>>
>> Dim iPEndPoint As IPEndPoint = Nothing
>>
>> Dim bs As Byte() = client.Receive( iPEndPoint)
>>
>> Dim m As IMessage = NHS.Messaging.U til.RetrieveMes sage(bs)
>>
>> If Not m Is Nothing Then 'Return
>>
>> message = m.MessageText
>>
>> ' need to use Invoke or BeginInvoke Syntax as message is on different
>> thread--
>>
>> Me.Invoke(New MethodInvoker(A ddressOf ShowRecvdMessag e))
>>
>> End If
>>
>> End While
>>
>> Catch e As Exception
>>
>> multicastExcept ion(e)
>>
>> End Try
>>
>> End Sub
>>
>>[/color]
>
>[/color]

[rawCoder]

Re: multithread method invoke

I read this solution some times ago on the newsgroup and was in the back of
my mind, but I forgot the datatype catch.
Well I think someone said that this line forces the handle to be created.
If this is THE window handle, then its very strange.
Some one has recommended to call the CreateHandle/CreateControl method as
well.

HTH
rawCoder