VB Net - Pass data from Thread to Main GUI - vb.net

Question

I've managed to get the data I want in a thread, however I'm having trouble getting my head around passing the data back into my main thread (GUI).
I'm grabbing data from a network stream in a thread, then need to pass it to my main thread in order to pass to other classes etc.
I've seen it mentioned to use backgroundworker for this, but as I'm expecting it to gather data periodically and never stop, I thought a separate thread for this would be best, but I'm very new to multithreading.
If threading is the correct way to go, how can I pass data from it back to my main thread in order to use this for other stuff? I've seen delegates and events mentioned a lot but can't see how I'd pass data with these?
Thanks

Answer 1

Please study this example, and let me know if it fits your requirements:
Controls required: lstItems (ListBox), btnStart (Button), btnStop (Button), Timer1 (Timer).
Form1 code:
Public Class Form1
Dim p_oStringProducer As StringProducer
Private Sub btnGo_Click(sender As Object, e As EventArgs) Handles btnGo.Click
p_oStringProducer = New StringProducer
p_oStringProducer.Start()
Timer1.Enabled = True
End Sub
Private Sub btnStop_Click(sender As Object, e As EventArgs) _
Handles btnStop.Click
Timer1.Enabled = False
p_oStringProducer.Stop()
End Sub
Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
Dim asQueue As Concurrent.ConcurrentQueue(Of String) =
p_oStringProducer.MessageQueue
While asQueue.Count > 0
Dim sItem As String = Nothing
asQueue.TryDequeue(sItem)
lstItems.Items.Add(sItem)
End While
End Sub
End Class
StringProducer code:
Imports System.Threading.Tasks
Public Class StringProducer
Private p_fKeepRunning As Boolean
Private p_oTask As task
Private p_aMessageQueue As Concurrent.ConcurrentQueue(Of String)
Private p_iNextMessageId As Integer
Public ReadOnly Property MessageQueue As _
Concurrent.ConcurrentQueue(Of String)
Get
Return p_aMessageQueue
End Get
End Property
Sub New()
p_oTask = New Task(AddressOf TaskBody)
p_aMessageQueue = New Concurrent.ConcurrentQueue(Of String)
p_iNextMessageId = 0
End Sub
Public Sub Start()
p_fKeepRunning = True
p_oTask.Start()
End Sub
Public Sub [Stop]()
p_fKeepRunning = False
End Sub
Private Sub TaskBody()
While p_fKeepRunning
Threading.Thread.Sleep(2000)
p_aMessageQueue.Enqueue("Message #" & p_iNextMessageId)
p_iNextMessageId += 1
End While
End Sub
Protected Overrides Sub Finalize()
MyBase.Finalize()
Me.Stop()
End Sub
End Class
This was not extensively tested, but it should give you a head start.