[RESOLVED] [VS 2010] [Multi-Threading] Invoke textbox to apply message, from another class.

[Frekvens1]

[Visual Studio 2010]

Hello again!

I'm doing a TCP server project which works great. However, the chat output won't display in my textbox in the main form. I've analyzed the code a little, but I don't seem to find a workaround. Here's the following code I'm using.

[NOTE] The TCP server runs on a different thread than the UI main thread.

Public Class cmd
    Public Class doCode
        Public Shared Sub Chat(ByVal [Message] As String)
            Functions.OutputString = [Message]
            Functions.EditTextDocument()
        End Sub
    End Class

    Public Class Functions
        Public Shared OutputString As String
        Private Delegate Sub DoStuffDelegate()
        Public Shared Sub EditTextDocument()

            If (Form1.InvokeRequired) Then 'Checks if the form needs to be invoked.
                Form1.Invoke(New DoStuffDelegate(AddressOf EditTextDocument)) 'Invokes the form
            Else
                Form1.txt_Output.Text &= Environment.NewLine & OutputString 'Adds the output stream from the Chat
            End If
        End Sub

    End Class

End Class

When a message from my TCP server is received, it will call the cmd.doCode.Chat(MessageReceived) sub. The function cmd.doCode.Chat will then try to invoke the textbox and add the message for server monitor display.

What I've found out so far:

*When I'm using this code in the main class, with all private, the textbox will get updated.
*When I use it from a different class than the main class, it won't.

The conclusion I'm drawing from this, is the way I call it Form1.Invoke might create a new thread, instead of using the main UI thread. I then tested with creating some variables to take the Form1 (Me) object on the journey from the beginning, to the end. Still no luck. In another project I fixed this issue by calling a variable at startup,

Dim myForm as Form = Form1

but it didn't work in this case. I'm not an expert at threading, and might overlooked some important notes with multi-threading. From what I believe so far, if I use multi-threading in another class, objects on invoke won't get updated.

My question is therefore, how can I update my objects on main UI thread, while doing multi-threading in a different class?

Thanks for hearing me out, and I hope you can lead me on the right track!

- Frek