紧急求助，不能隐藏开始按钮！

代码以下：
Public Class Form1
    Structure RECT
        Public Left As Long
        Public Top As Long
        Public Right As Long
        Public Bottom As Long
    End Structure
    Private Declare Function ShowWindow Lib "user32" (ByVal hwnd As Long, ByVal nCmdShow As Long) As Long
    '控制窗口的可见性
    'hwnd窗口句柄，要向这个窗口应用由nCmdShow指定的命令
    'nCmdShow为窗口指定可视性方面的一个命令
    Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
    '寻找窗口列表中第一个符合指定条件的顶级窗口
    'lpClassName指向包含了窗口类名的空中止（C语言）字串的指针；或设为零，'表示接收任何类
    'lpWindowName指向包含了窗口文本（或标签）的空中止（C语言）字串的指针；'或设为零，表示接收任何窗口标题
    Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long
    '在窗口列表中寻找与指定条件相符的第一个子窗口
    'hWnd1在其中查找子的父窗口
    'hWnd2从这个窗口后开始查找。这样便可利用对FindWindowEx的多次调用找到符合条件的所有子窗口。如设为零，表示从第一个子窗口开始搜索
    Private Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Long, ByVal dwReserved As Long)
    '退出windows，并用特定的选项重新启动
    Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, ByRef lpvParam As RECT, ByVal fuWinIni As Long) As Long
    '允许获取和设置数量众多的windows系统参数
    'uAction指定要设置的参数
    Public Declare Function IsWindowVisible Lib "user32" (ByVal hwnd As Long) As Long '判断窗口是否可见

    Private Sub hideBut_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles hideBut.Click
        Dim Handle As Long, FindClass As Long
        FindClass = FindWindow("Shell_TrayWnd", "")
        Handle = FindWindowEx(FindClass, 0, "Button", vbNullString)
        ShowWindow(Handle, 0)
    End Sub

    Private Sub showBut_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles showBut.Click
        Dim Handle As Long, FindClass As Long
        MessageBox.Show("WorkAreaLeft: ")
        FindClass = FindWindow("Shell_TrayWnd", "")
        Handle = FindWindowEx(FindClass, 0, "Button", vbNullString)
        ShowWindow(Handle, 1)
    End Sub
End Class

运行后点按钮就是隐藏不了开始菜单，什么反应没有，这是怎么回事呢？我看网上都是这么写的啊！ --------------------编程问答-------------------- 我求助啊！！！！！ --------------------编程问答-------------------- Long -> Integer

补充：.NET技术 ,  VB.NET