vb.net多线程

Public Class Form1

    Dim myThread As Threading.Thread
    Public Delegate Sub SetTextStringDelegate(ByVal tb As TextBox, ByVal str As String)
    Public Sub SetTextStringInvoke(ByVal tb As TextBox, ByVal str As String)
        tb.Text = str
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        myThread = New Threading.Thread(AddressOf SetTextString)
        myThread.Start()
    End Sub
    Private Sub SetTextString()

        TextBox1.Invoke(New SetTextStringDelegate(AddressOf SetTextStringInvoke), New Object() {TextBox1, "多线程访问界面"})

    End Sub

End Class