Синхронизация scrollbar из datagridview и кастомного трекбара

Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms
Imports System.Diagnostics
 
Public Partial Class Form1
    Inherits Form
 
    Private pt As Point
 
    Public Sub New()
        InitializeComponent()
 
        Dim b As New Button()
        b.Location = New Point(0, 300)
        b.Text = "test"
        Me.innerPanel.Controls.Add(b)
 
        pt = New Point(Me.innerPanel.AutoScrollPosition.X, Me.innerPanel.AutoScrollPosition.Y)
        Me.customScrollbar1.Minimum = 0
        Me.customScrollbar1.Maximum = Me.innerPanel.DisplayRectangle.Height
        Me.customScrollbar1.LargeChange = customScrollbar1.Maximum \ customScrollbar1.Height + Me.innerPanel.Height
        Me.customScrollbar1.SmallChange = 15
        Me.customScrollbar1.Value = Math.Abs(Me.innerPanel.AutoScrollPosition.Y)
 
        Me.vScrollBar1.Minimum = 0
        Me.vScrollBar1.Maximum = Me.innerPanel.DisplayRectangle.Height
        Me.vScrollBar1.LargeChange = vScrollBar1.Maximum \ vScrollBar1.Height + Me.innerPanel.Height
        Me.vScrollBar1.SmallChange = 15
 
        Me.vScrollBar1.Value = Math.Abs(Me.innerPanel.AutoScrollPosition.Y)
    End Sub
 
    Private Sub customScrollbar1_Scroll(ByVal sender As Object, ByVal e As EventArgs) Handles CustomScrollbar1.Scroll
        innerPanel.AutoScrollPosition = New Point(0, CustomScrollbar1.Value)
        VScrollBar1.Value = CustomScrollbar1.Value
        CustomScrollbar1.Invalidate()
        Application.DoEvents()
        Debug.WriteLine("vscroll: " & VScrollBar1.Value.ToString() & "  custom: " & CustomScrollbar1.Value.ToString())
    End Sub
 
    Private Sub vScrollBar1_Scroll(ByVal sender As Object, ByVal e As ScrollEventArgs)
        innerPanel.AutoScrollPosition = New Point(0, VScrollBar1.Value)
        CustomScrollbar1.Value = VScrollBar1.Value
        Application.DoEvents()
        Debug.WriteLine("vscroll: " & VScrollBar1.Value.ToString() & "  custom: " & CustomScrollbar1.Value.ToString())
    End Sub
 
    Private Sub btnHidePanelScrollbar_Click(ByVal sender As Object, ByVal e As EventArgs)
        If btnHidePanelScrollbar.Text = "Hide Panel Scrollbar" Then
            outerPanel.Width -= 20
            CustomScrollbar1.Left -= 20
            btnHidePanelScrollbar.Text = "Show Panel Scrollbar"
        Else
            outerPanel.Width += 20
            CustomScrollbar1.Left += 20
            btnHidePanelScrollbar.Text = "Hide Panel Scrollbar"
        End If
    End Sub
End Class