用VB编写一个弹出菜单类

'类的名称为cPopupMenu

Option Explicit

'

Private Type POINT

x As Long

y As Long

End Type

'

Private Const MF_ENABLED = &H0&

Private Const MF_SEPARATOR = &H800&

Private Const MF_STRING = &H0&

Private Const TPM_RIGHTBUTTON = &H2&

Private Const TPM_LEFTALIGN = &H0&

Private Const TPM_NONOTIFY = &H80&

Private Const TPM_RETURNCMD = &H100&

Private Declare Function CreatePopupMenu Lib "user32" () As Long

Private Declare Function AppendMenu Lib "user32" Alias "AppendMenuA" (ByVal hMenu As Long, ByVal wFlags As Long, ByVal wIDNewItem As Long, ByVal sCaption As String) As Long

Private Declare Function TrackPopupMenu Lib "user32" (ByVal hMenu As Long, ByVal wFlags As Long, ByVal x As Long, ByVal y As Long, ByVal nReserved As Long, ByVal hwnd As Long, nIgnored As Long) As Long

Private Declare Function DestroyMenu Lib "user32" (ByVal hMenu As Long) As Long

Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINT) As Long

Private Declare Function GetForegroundWindow Lib "user32" () As Long

Private Declare Function GetMenuString Lib "user32" Alias "GetMenuStringA" (ByVal hMenu As Long, ByVal wIDItem As Long, ByVal lpString As String, ByVal nMaxCount As Long, ByVal wFlag As Long) As Long

Private mSelMenuString As String

Public Property Get SelMenuString() As String

SelMenuString = mSelMenuString

End Property

'

Public Function Popup(ParamArray param()) As Long

Dim iMenu As Long

Dim hMenu As Long

Dim nMenus As Long

Dim p As POINT

' get the current cursor pos in screen coordinates

GetCursorPos p

' create an empty popup menu

hMenu = CreatePopupMenu()

' determine # of strings in paramarray

nMenus = 1 + UBound(param)

' put each string in the menu

For iMenu = 1 To nMenus

' the AppendMenu function has been superseeded by the InsertMenuItem

' function, but it is a bit easier to use.

If Trim$(CStr(param(iMenu - 1))) = "-" Then

' if the parameter is a single dash, a separator is drawn

AppendMenu hMenu, MF_SEPARATOR, iMenu, ""

Else

AppendMenu hMenu, MF_STRING + MF_ENABLED, iMenu, CStr(param(iMenu - 1))

End If

Next iMenu

' show the menu at the current cursor location;

' the flags make the menu aligned to the right (!); enable the right button to select

' an item; prohibit the menu from sending messages and make it return the index of

' the selected item.

' the TrackPopupMenu function returns when the user selected a menu item or cancelled

' the window handle used here may be any window handle from your application

' the return value is the (1-based) index of the menu item or 0 in case of cancelling

iMenu = TrackPopupMenu(hMenu, TPM_RIGHTBUTTON + TPM_LEFTALIGN + TPM_NONOTIFY + TPM_RETURNCMD, p.x, p.y, 0, GetForegroundWindow(), 0)

Dim result As Long

Dim buffer As String

Const MF_BYPOSITION = &H400&

buffer = Space(255)

result = GetMenuString(hMenu, (iMenu - 1), buffer, _

Len(buffer), MF_BYPOSITION)

'Debug.Print buffer

mSelMenuString = Trim(buffer)

' release and destroy the menu (for sanity)

DestroyMenu hMenu

' return the selected menu item's index

Popup = iMenu

End Function

'结束

'以下是实例，在Form上添加一个ListBox控件

Option Explicit

Private Sub Form_Load()

List1.AddItem "Right-Click here for a menu"

End Sub

Private Sub List1_MouseUp(Button As Integer, Shift As Integer, x As Single, y As Single)

Dim oMenu As cPopupMenu

Dim lMenuChosen As Long

'

If Button = vbRightButton Then

Set oMenu = New cPopupMenu

'

' Pass in the desired menu, use '-' for a separator

'

lMenuChosen = oMenu.Popup("Menu 1", "Menu 2", "Menu 3", _

"-", "Menu 4")

'

Debug.Print lMenuChosen

Debug.Print oMenu.SelMenuString

End If

'

End Sub