.NET (Core and Framework)

Imports System.Threading

Public Class Form1
  Dim MyNewThread As Thread
  Dim tmp As Int32 = 0

  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    'create the thread
    MyNewThread = New Thread(AddressOf SubDelThread)
    MyNewThread.Name = "NuovoThread"
    'start the thread
    MyNewThread.Start()
  End Sub


  Private Sub SubDelThread()
    Do
      tmp = tmp + 1
      AggLab()
      Thread.Sleep(1000)
    Loop
  End Sub

  Private Delegate Sub AggLabDel()
  Private Sub AggLab()

    If Me.InvokeRequired Then
      Me.BeginInvoke(New AggLabDel(AddressOf AggLab))
      Return
    End If

    Label1.Text = tmp.ToString

  End Sub

End Class

'file Form1.vb

Imports System.Threading

Public Class Form1
  Dim MyNewThread As Thread

  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    'create the thread 
    MyNewThread = New Thread(AddressOf MyThread.MyThreadExecute)
    MyNewThread.Name = "NuovoThread"
    'start the thread
    MyNewThread.Start()
  End Sub

  Private Delegate Sub AggiornaLabelDelegate()
  Public Sub AggiornaLabel()

    If Me.InvokeRequired Then
      Me.BeginInvoke(New AggiornaLabelDelegate(AddressOf AggiornaLabel))
      Return
    End If

    Label1.Text = MyThread.iii.ToString

  End Sub

'file MyThread.vb

Imports System.Threading

Public Class MyThread
  Private Shared miii As Int32 = 0

  Public Shared Property iii() As Int32
    Get
      Return miii
    End Get
    Set(ByVal value As Int32)
      miii = value
    End Set
  End Property

  Public Shared Sub MyThreadExecute()
    Do
      iii = iii + 1
      Form1.AggiornaLabel()
      Thread.Sleep(1000)
    Loop
  End Sub

End Class