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向COM对象的VBScript用户公开事件处理程序

c++builder vbscript com events

Carl · 技术社区 · 16 年前

假设我有一个COM对象,用户可以通过调用访问该对象,例如:

Set s = CreateObject("Server")

Function ServerEvent

   MsgBox "Event handled"

End Function

s.OnDoSomething = ServerEvent

这是可能的吗?如果是,我如何在C++中的我的类型库中公开这个(具体地说是BCB 2007)?

3 回复 | 直到 15 年前

Jeff Hillman 16 年前

[
    object,
    uuid(6EDA5438-0915-4183-841D-D3F0AEDFA466),
    nonextensible,
    oleautomation,
    pointer_default(unique)
]
interface IServerEvents : IDispatch
{
    [id(1)]
    HRESULT OnServerEvent();
}

//...

[
    uuid(FA8F24B3-1751-4D44-8258-D649B6529494),
]
coclass ServerEvents
{
    [default] interface IServerEvents;
    [default, source] dispinterface IServerEvents;
};

以下是CServerEvents类的声明:

class ATL_NO_VTABLE CServerEvents :
    public CComObjectRootEx<CComSingleThreadModel>,
    public CComCoClass<CServerEvents, &CLSID_ServerEvents>,
    public IDispatchImpl<IServerEvents, &IID_IServerEvents , &LIBID_YourLibrary, -1, -1>,
    public IConnectionPointContainerImpl<CServerEvents>,
    public IConnectionPointImpl<CServerEvents,&__uuidof(IServerEvents)>
{
public:
    CServerEvents()
    {
    }

    // ...

BEGIN_COM_MAP(CServerEvents)
    COM_INTERFACE_ENTRY(IServerEvents)
    COM_INTERFACE_ENTRY(IDispatch)
    COM_INTERFACE_ENTRY(IConnectionPointContainer)
END_COM_MAP()

BEGIN_CONNECTION_POINT_MAP(CServerEvents)
    CONNECTION_POINT_ENTRY(__uuidof(IServerEvents))
END_CONNECTION_POINT_MAP()

    // ..

    // IServerEvents
    STDMETHOD(OnServerEvent)();

private:
    CRITICAL_SECTION m_csLock;        
};

这里的关键是IConnectionPointImpl和IConnectionPointContainerImpl接口和连接点映射的实现。OnServerEvent方法的定义如下所示:

STDMETHODIMP CServerEvents::OnServerEvent()
{
    ::EnterCriticalSection( &m_csLock );

    IUnknown* pUnknown;

    for ( unsigned i = 0; ( pUnknown = m_vec.GetAt( i ) ) != NULL; ++i )
    {       
        CComPtr<IDispatch> spDisp;
        pUnknown->QueryInterface( &spDisp );

        if ( spDisp )
        {
            spDisp.Invoke0( CComBSTR( L"OnServerEvent" ) );
        }
    }

    ::LeaveCriticalSection( &m_csLock );

    return S_OK;
}

STDMETHOD(DoSomethingAsynchronous)( IServerEvents *pCallback );

存储指向IServerEvents的指针,然后当您要激发事件时,只需调用方法:

m_pCallback->OnServerEvent();

对于VB代码,处理事件的语法与您建议的略有不同:

Private m_server As Server
Private WithEvents m_serverEvents As ServerEvents

Private Sub MainMethod()
    Set s = CreateObject("Server")
    Set m_serverEvents = New ServerEvents

    Call m_searchService.DoSomethingAsynchronous(m_serverEvents)
End Sub

Private Sub m_serverEvents_OnServerEvent()
    MsgBox "Event handled"
End Sub

希望这有帮助。

1800 INFORMATION 16 年前

http://msdn.microsoft.com/en-us/library/ms974564.aspx

看起来您的服务器对象需要实现 IProvideClassInfo 然后你打电话来 ConnectObject

http://blogs.msdn.com/ericlippert/archive/2005/02/15/373330.aspx

Brian Webster Jason 13 年前

我最终还是采用了描述的技术 here .