摘自：http://stackoverflow.com/questions/4615940/how-can-i-customize-the-system-menu-of-a-windows-form

在单击窗体左上角图标，或标题栏右击时，显示自定义菜单

 

Imports System.Windows.FormsImports System.Runtime.InteropServicesPublic Class CustomForm    Inherits Form    ' P/Invoke constants    Private Const WM_SYSCOMMAND As Integer = &H112    Private Const MF_STRING As Integer = &H0    Private Const MF_SEPARATOR As Integer = &H800    ' P/Invoke declarations    
     
          Private Shared Function GetSystemMenu(hWnd As IntPtr, bRevert As Boolean) As IntPtr    End Function    
      
           Private Shared Function AppendMenu(hMenu As IntPtr, uFlags As Integer, uIDNewItem As Integer, lpNewItem As String) As Boolean    End Function    
       
            Private Shared Function InsertMenu(hMenu As IntPtr, uPosition As Integer, uFlags As Integer, uIDNewItem As Integer, lpNewItem As String) As Boolean    End Function    ' ID for the About item on the system menu    Private SYSMENU_ABOUT_ID As Integer = &H1    Public Sub New()    End Sub    Protected Overrides Sub OnHandleCreated(e As EventArgs)        MyBase.OnHandleCreated(e)        ' Get a handle to a copy of this form's system (window) menu        Dim hSysMenu As IntPtr = GetSystemMenu(Me.Handle, False)        ' Add a separator        AppendMenu(hSysMenu, MF_SEPARATOR, 0, String.Empty)        ' Add the About menu item        AppendMenu(hSysMenu, MF_STRING, SYSMENU_ABOUT_ID, "&About…")    End Sub    Protected Overrides Sub WndProc(ByRef m As Message)        MyBase.WndProc(m)        ' Test if the About item was selected from the system menu        If m.Msg = WM_SYSCOMMAND AndAlso m.WParam.ToInt32 = SYSMENU_ABOUT_ID Then            MessageBox.Show("Custom About Dialog")        End If    End SubEnd Class