[.NET] VB .NET 08 AppBar Problem

Imports System.Runtime.InteropServices
Public Class frmMain
 Private Sub frmMain_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
 RegisterBar(Me, ABEdge.ABE_TOP)
 End Sub
 Private Sub frmMain_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
 RegisterBar(Me)
 End Sub


 <StructLayout(LayoutKind.Sequential)> Structure RECT
 Public left As Integer
 Public top As Integer
 Public right As Integer
 Public bottom As Integer
 End Structure
 <StructLayout(LayoutKind.Sequential)> Structure APPBARDATA
 Public cbSize As Integer
 Public hWnd As IntPtr
 Public uCallbackMessage As Integer
 Public uEdge As Integer
 Public rc As RECT
 Public lParam As IntPtr
 End Structure
 Enum ABMsg
 ABM_NEW = 0
 ABM_REMOVE = 1
 ABM_QUERYPOS = 2
 ABM_SETPOS = 3
 ABM_GETSTATE = 4
 ABM_GETTASKBARPOS = 5
 ABM_ACTIVATE = 6
 ABM_GETAUTOHIDEBAR = 7
 ABM_SETAUTOHIDEBAR = 8
 ABM_WINDOWPOSCHANGED = 9
 ABM_SETSTATE = 10
 End Enum
 Enum ABNotify
 ABN_STATECHANGE = 0
 ABN_POSCHANGED
 ABN_FULLSCREENAPP
 ABN_WINDOWARRANGE
 End Enum
 Enum ABEdge
 ABE_LEFT = 0
 ABE_TOP
 ABE_RIGHT
 ABE_BOTTOM
 End Enum
 Private fBarRegistered As Boolean = False
 <DllImport("SHELL32", CallingConvention:=CallingConvention.StdCall)> _
 Public Shared Function SHAppBarMessage(ByVal dwMessage As Integer, ByRef BarrData As APPBARDATA) As Integer
 End Function
 <DllImport("USER32")> _
 Public Shared Function GetSystemmetric(ByVal Index As Integer) As Integer
 End Function
 <DllImport("User32.dll", ExactSpelling:=True, CharSet:=System.Runtime.InteropServices.CharSet.Auto)> _
 Public Shared Function MoveWindow(ByVal hWnd As IntPtr, ByVal x As Integer, ByVal y As Integer, ByVal cX As Integer, ByVal cY As Integer, ByVal repaint As Boolean) As Boolean
 End Function
 <DllImport("User32.dll", CharSet:=CharSet.Auto)> _
 Public Shared Function RegisterWindowMessage(ByVal msg As String) As Integer
 End Function
 Private uCallBack As Integer

 Public Sub RegisterBar(ByVal frm As Form, Optional ByVal dockEdge As ABEdge = ABEdge.ABE_TOP)
 Dim abd As New APPBARDATA
 Dim ret As Integer
 abd.cbSize = Marshal.SizeOf(abd)
 abd.hWnd = Me.Handle
 If Not fBarRegistered Then
 uCallBack = RegisterWindowMessage("AppBarMessage")
 abd.uCallbackMessage = uCallBack

 ret = SHAppBarMessage(ABMsg.ABM_NEW, abd)
 fBarRegistered = True

 ABSetPos()
 Else
 ret = SHAppBarMessage(ABMsg.ABM_REMOVE, abd)
 fBarRegistered = False
 End If
 End Sub

 Private Sub ABSetPos()
 Dim abd As New APPBARDATA
 abd.cbSize = Marshal.SizeOf(abd)
 abd.hWnd = Me.Handle
 abd.uEdge = ABEdge.ABE_TOP

 If abd.uEdge = ABEdge.ABE_LEFT OrElse abd.uEdge = ABEdge.ABE_RIGHT Then
 abd.rc.top = 0
 abd.rc.bottom = SystemInformation.PrimaryMonitorSize.Height
 If abd.uEdge = ABEdge.ABE_LEFT Then
 abd.rc.left = 0
 abd.rc.right = Size.Width
 Else
 abd.rc.right = SystemInformation.PrimaryMonitorSize.Width
 abd.rc.left = abd.rc.right - Size.Width
 End If
 Else
 abd.rc.left = 0
 abd.rc.right = SystemInformation.PrimaryMonitorSize.Width
 If abd.uEdge = ABEdge.ABE_TOP Then
 abd.rc.top = 0
 abd.rc.bottom = Size.Height
 Else
 abd.rc.bottom = SystemInformation.PrimaryMonitorSize.Height
 abd.rc.top = abd.rc.bottom - Size.Height
 End If
 End If

 'Query the system for an approved size and position.
 SHAppBarMessage(ABMsg.ABM_QUERYPOS, abd)

 'Adjust the rectangle, depending on the edge to which the appbar is anchored.
 Select Case abd.uEdge
 Case ABEdge.ABE_LEFT
 abd.rc.right = abd.rc.left + Size.Width
 Case ABEdge.ABE_RIGHT
 abd.rc.left = abd.rc.right - Size.Width
 Case ABEdge.ABE_TOP
 abd.rc.bottom = abd.rc.top + Size.Height
 Case ABEdge.ABE_BOTTOM
 abd.rc.top = abd.rc.bottom - Size.Height
 End Select

 'Pass the final bounding rectangle to the system.
 SHAppBarMessage(ABMsg.ABM_SETPOS, abd)

 'Move and size the appbar so that it conforms to the bounding rectangle passed to the system.
 MoveWindow(abd.hWnd, abd.rc.left, abd.rc.top, abd.rc.right - abd.rc.left, abd.rc.bottom - abd.rc.top, True)

 End Sub


 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 End
 End Sub
End Class