Обновление формы после изменения данных

Imports NAudio.Wave
 
Public Class MainForm
    Dim Str As String
    Public Sub New()
        InitializeComponent()
    End Sub
 
    Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
 
        Str = TextBox1.Text
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim waveOut = New WaveOut()
        Dim osc = New SineWaveOscillator(44100)
        osc.Frequency = Str
        osc.Amplitude = 8192
        waveOut.Init(osc)
        waveOut.Play()
    End Sub
 
    Private Sub MainForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
 
    End Sub
 
End Class
 
Public Class SineWaveOscillator
    Inherits WaveProvider16
 
    Dim phaseAngle As Double
 
    Public Sub New(sampleRate As Int32)
        MyBase.New(sampleRate, 1)
    End Sub
 
    Public Property Frequency As Double
    Public Property Amplitude As Short
 
    Public Overrides Function Read(buffer() As Short, _
        offset As Integer, sampleCount As Integer) As Integer
        For index = 0 To sampleCount
            buffer(offset + index) = Amplitude * Math.Sin(phaseAngle)
            phaseAngle += 2 * Math.PI * Frequency / WaveFormat.SampleRate
            If phaseAngle > 2 * Math.PI Then
                phaseAngle -= 2 * Math.PI
            End If
        Next
        Return sampleCount
    End Function
End Class