Связать ProgressBar + скорлинг в Texbox

public class MyTextBox : TextBox
    {
        public delegate void OnScrollEvent(object sender, int Min, int Max, int Pos);


        public event OnScrollEvent OnScrollChanged;

        public int VerticalScrollPosition
        { 
            get { return GetScroll(WinApi.SB_VERT); }
        }

        private int GetScroll(int scrollBarMessage)
        {
            return WinApi.GetScrollPos((System.IntPtr)this.Handle, scrollBarMessage);
        }         

        protected override void WndProc(ref System.Windows.Forms.Message message)
        {
            base.WndProc(ref message);
            if (message.Msg == WinApi.WM_VSCROLL || message.Msg == WinApi.WM_HSCROLL || message.Msg == WinApi.WM_MOUSEWHEEL)
            {
            }

            if (message.Msg == WinApi.WM_VSCROLL )
            {
                WinApi.SCROLLINFO info = new WinApi.SCROLLINFO();
                info.cbSize = Marshal.SizeOf(info);
                info.fMask = WinApi.ScrollInfoMask.SIF_ALL;
                WinApi.GetScrollInfo(this.Handle, WinApi.SB_VERT, ref info);
                OnScrollChanged?.Invoke(this, info.nMin, info.nMax, info.nPos);
            }
        }
    }


    public static class WinApi
    {
        public enum ScrollInfoMask : uint
        {
            SIF_RANGE = 0x1,
            SIF_PAGE = 0x2,
            SIF_POS = 0x4,
            SIF_DISABLENOSCROLL = 0x8,
            SIF_TRACKPOS = 0x10,
            SIF_ALL = (SIF_RANGE | SIF_PAGE | SIF_POS | SIF_TRACKPOS),
        }

        public const uint WM_HSCROLL = 0x114;
        public const uint WM_VSCROLL = 0x115;
        public const uint WM_MOUSEWHEEL = 0x20A;
        public const int SB_VERT = 0x1;
        public const int SB_HORZ = 0x0;

        [Serializable, StructLayout(LayoutKind.Sequential)]
        public struct SCROLLINFO
        {
            public int cbSize; // (uint) int is because of Marshal.SizeOf
            public ScrollInfoMask fMask;
            public int nMin;
            public int nMax;
            public uint nPage;
            public int nPos;
            public int nTrackPos;
        }

        [System.Runtime.InteropServices.DllImport("user32.dll")]
        public static extern int SetScrollPos(System.IntPtr hWnd, int nBar, int nPos, bool bRedraw);

        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool GetScrollInfo(IntPtr hwnd, int fnBar, ref SCROLLINFO lpsi);


        [System.Runtime.InteropServices.DllImport("user32.dll")]
        public static extern int GetScrollPos(System.IntPtr hWnd, int nBar);

        [System.Runtime.InteropServices.DllImport("User32.Dll", EntryPoint = "PostMessageA")]
        public static extern bool PostMessage(System.IntPtr hWnd, uint msg, int wParam, int lParam);
    }

 myTextBox1.OnScrollChanged += (ox, a, b, c) =>
              {
                  this.BeginInvoke(new MethodInvoker(() =>
                  {
                      if (progressBar1.Minimum != a)
                          progressBar1.Minimum = a;
                      if (progressBar1.Maximum != b)
                          progressBar1.Maximum = b;
                      progressBar1.Step = 1;
                      progressBar1.Value = Math.Min(b, c);
                  }));
              };