สอบถามเรื่องการนำค่าความดังของเสียงที่รับจากไมค์ไปแสดงค่าใน textbox ด้วยภาษา VB.NET

Imports System.ComponentModel
Imports VUMeter.SampleAudioAPI

Public Class Mixer
    Private AudioAPI As New SampleAudioAPI()
    Private WithEvents Observer As New Windows.Forms.Timer() With {.Interval = 10, .Enabled = True}

    Sub New()
        InitializeComponent()
        MICROPHONE_BAR.Maximum = 200
    End Sub
    Private Sub Start(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load

        IN_MasterScalarValue = AudioAPI.IN_MasterScalar
        RaiseEvent MicrophoneValueChanged(IN_MasterScalarValue)

    End Sub
    Private Sub Observer_Tick(ByVal sender As Object, ByVal e As EventArgs) Handles Observer.Tick

        If Not ((MICROPHONE.Checked = False) And (AudioAPI.IN_MUTE = True)) Then
            MICROPHONE.Checked = If(AudioAPI.IN_MUTE = True, False, True)
        End If

        Refresher()

    End Sub
    Private IN_MasterScalarValue As Single = 0.0F
    Private Event MicrophoneValueChanged(ByVal value As Single)
    Private Sub Microphone_ValueChanged(ByVal value As Single) Handles Me.MicrophoneValueChanged
        IN_MasterScalarValue = value
        MICROPHONE_BAR.Value = (SingleToIntPercentage(value))
    End Sub

    Dim _SMOOTHTRANSITION As Boolean = True
    Private Sub Refresher()
        'ไมค์
        VPB_IN_MASTER.Value = SingleToIntPercentage(AudioAPI.Value(Channels.IN_Master, _SmoothTransition))
    End Sub
    Private Sub Microphone_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MICROPHONE.CheckedChanged
        'เช็ค MUTE
        AudioAPI.IN_MUTE = If(MICROPHONE.Checked = True, False, True)
    End Sub
    Private Sub Microphone_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MICROPHONE_BAR.Scroll
        AudioAPI.IN_MasterScalar = IntToSinglePercentage(MICROPHONE_BAR.Value)
    End Sub

    Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
        Dim value As String = Convert.ToString(value)
        TextBox1.Text = value(0)
    End Sub

End Class

<BrowsableAttribute(True), DescriptionAttribute("Vertical ProgressBar.")>
Public NotInheritable Class VerticalProgressBar
    Inherits ProgressBar

    Protected Overloads Overrides ReadOnly Property CreateParams() As CreateParams
        Get
            Dim cp As CreateParams = MyBase.CreateParams
            cp.Style = cp.Style Or &H4
            Return cp
        End Get
    End Property
End Class

Code (VB.NET)