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]

Just a trick, see if it works,

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

HTH
rawCoder

"m.posseth" <mi*****@nohaus ystems.nl> wrote in message
news:42******** *************** @nova.planet.nl ...

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

[m.posseth]

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" <ra******@hotma il.com> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..

Just a trick, see if it works,

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

HTH
rawCoder

"m.posseth" <mi*****@nohaus ystems.nl> wrote in message
news:42******** *************** @nova.planet.nl ...

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]

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