---- 启动Visual Basic，新建标准EXE工程，在工程中添加一标准模块，名称可以是默认的。在标准模块的声明部分加入下列代码： '菜单API函数声明 Public Declare Function GetSystemMenu Lib "user32" (ByVal hwnd As Long, ByVal bRevert As Long) As Long Public Declare Function AppendMenu Lib "user32" Alias "AppendMenuA" (ByVal hMenu As Long, ByVal wFlags As Long, ByVal wIDNewItem As Long, ByVal lpNewItem As Any) As Long '菜单API函数常数声明 Public Const MF_BYCOMMAND = "H0" Public Const MF_SEPARATOR ="H800" Public Const MF_STRING = "H0" '有关窗口函数的API函数声明 Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long,ByVal dwNewLong As Long) As Long Public Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long Public Declare Function DefWindowProc Lib "user32" Alias "DefWindowProcA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long '消息 Public Const GWL_WNDPROC = (-4) Public Const WM_NCLBUTTONDOWN = "HA1" Public Const WM_NCRBUTTONDOWN = "HA4" Public Const WM_USER = "H400" Public Const WM_SYSCOMMAND = "H112" Public Const HTSYSMENU = 3 Public Const HTCAPTION = 2 '自定义菜单项的标识号偏移量 Public Const IDM_SEPARATOR = 1 Public Const IDM_MYABOUT = 2 '其他变量 Dim sHwnd As Long Dim OldProc As Long 接着可向标准模块添加下面两个过程： Public Sub AddMenu(frm As Form) '置换窗口函数过程 sHwnd = frm.hwnd OldProc = SetWindowLong(frm.hwnd, GWL_WNDPROC, AddressOf AddCallBack) End Sub Public Sub Release() '释放自定义窗口函数过程 SetWindowLong sHwnd,GWL_WNDPROC, OldProc End Sub 最后向标准模块中添加一自定义窗口函数过程： Public Function AddCallBack(ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long Select Case wMsg Case WM_SYSCOMMAND '系统消息 Select Case wParam '测试 Case WM_USER + IDM_MYABOUT '"关于..."菜单项 '此处可加入用户需要自己处理"关于…" 菜单项的代码 MsgBox "单击了添加的菜单条目",vbOKOnly Case Else '其它菜单项交换系统处理 AddCallBack =DefWindowProc(hwnd, wMsg, wParam, lParam) End Select Exit Function Case Else AddCallBack = CallWindowProc(OldProc, hwnd, wMsg, wParam, lParam) End Select End Function 关闭标准模块的代码窗口，打开窗体的代码窗口， 在Form_Load()过程中加入下列代码： '加载自定义窗口过程 AddMenu Me '获得系统菜单的句柄 Dim hMenu As Long hMenu = GetSystemMenu(Me.hwnd, 0) '在系统菜单中添加自定义2条菜单项 AppendMenu hMenu, MF_SEPARATOR Or MF_BYCOMMAND, IDM_SEPARATOR, vbNullString '分隔符 AppendMenu hMenu, MF_BYCOMMAND Or MF_STRING, WM_USER + IDM_MYABOUT, "关于..." ' "关于…"菜单项 在Form_Unload过程中加入下列代码： Release '释放自定义窗口过程