1、给控件类加上IPerPropertyBrowsingImpl接口

public IPerPropertyBrowsingImpl

在BEGIN_COM_MAP/END_COM_MAP()中间加上

COM_INTERFACE_ENTRY_IMPL(IPerPropertyBrowsing)

2、 在该类中添加下列函数

(A)STDMETHOD(MapPropertyToPage)(DISPID dispid, CLSID *pClsid);
(B)STDMETHOD(GetPredefinedStrings)(DISPID dispid, CALPOLESTR *pCaStringOut, CADWORD *pCaCookiesOut);
(C)STDMETHOD(GetPredefinedValue)(DISPID dispid, DWORD dwCookie, VARIANT *pVarOut);
(D) STDMETHOD(GetDisplayString)(DISPID dispid, BSTR *pBstr);

STDMETHODIMP CCameraCtrl::MapPropertyToPage(DISPID dispid, CLSID *pClsid)
{
    switch (dispid)
    {
    case dispidDeviceSource:
        return E_NOTIMPL; // 如果要自己实现下拉列表则返回E_NOIMPL
    default:
        break;
    }
    return IPerPropertyBrowsingImpl<CCameraCtrl>::MapPropertyToPage(dispid, pClsid);
}

STDMETHODIMP CCameraCtrl::GetPredefinedStrings(DISPID dispid, CALPOLESTR *pCaStringOut, CADWORD *pCaCookiesOut)
{
    USES_CONVERSION;
    HRESULT hr = S_OK;

    if ((NULL == pCaStringOut) || (NULL == pCaCookiesOut))
    {
        return E_POINTER;
    }

    if (dispid == dispidDeviceSource)
    {
        ULONG ulElems = 3;
        pCaStringOut->pElems = (LPOLESTR*)::CoTaskMemAlloc(sizeof(LPOLESTR) * ulElems);
        if (NULL == pCaStringOut->pElems)
        {
            return E_OUTOFMEMORY;
        }
       
        pCaCookiesOut->pElems = (DWORD*)::CoTaskMemAlloc(sizeof(DWORD*) * ulElems);
        if (NULL == pCaCookiesOut->pElems)
        {
            CoTaskMemFree(pCaStringOut->pElems);
            return E_OUTOFMEMORY;
        }
       
        pCaStringOut->cElems = ulElems;
        pCaCookiesOut->cElems = ulElems;

        char *szName[3] = {"Device0", "Device1", "Device2"};

        pCaStringOut->pElems[0] = ATLA2WHELPER((LPWSTR)::CoTaskMemAlloc((sizeof(szName[0]) + 1) * 2), szName[0], lstrlen(szName[0]) + 1);
        pCaStringOut->pElems[1] = ATLA2WHELPER((LPWSTR)::CoTaskMemAlloc((sizeof(szName[0]) + 1) * 2), szName[1], lstrlen(szName[1]) + 1);
        pCaStringOut->pElems[2] = ATLA2WHELPER((LPWSTR)::CoTaskMemAlloc((sizeof(szName[0]) + 1) * 2), szName[2], lstrlen(szName[2]) + 1);

        pCaCookiesOut->pElems[0] = 0;
        pCaCookiesOut->pElems[1] = 1;
        pCaCookiesOut->pElems[2] = 2;
   
        hr = S_OK;
    }

    return hr;
}

STDMETHODIMP CCameraCtrl::GetPredefinedValue(DISPID dispid, DWORD dwCookie, VARIANT *pVarOut)
{
    BOOL bResult = FALSE;

    switch (dispid)
    {
    case dispidDeviceSource:
        VariantInit(pVarOut);
        pVarOut->vt = VT_I4;
        pVarOut->lVal = dwCookie;
        bResult = TRUE;
        break;
    default:
        break;
    }

    return bResult;
}

STDMETHODIMP CCameraCtrl::GetDisplayString(DISPID dispid, BSTR *pBstr)
{
    USES_CONVERSION;
    HRESULT hr = S_FALSE;

    switch (dispid)
    {
    case dispidDeviceSource:
        switch (m_lDeviceSource)
        {
        case 0:
            *pBstr = ::SysAllocString(T2OLE("Device0"));
            break;
        case 1:
            *pBstr = ::SysAllocString(T2OLE("Device1"));
            break;
        case 2:
            *pBstr = ::SysAllocString(T2OLE("Device2"));
            break;
        default:
            break;
        }
        hr = S_OK;
        break;
    default:
        break;
    }

    return hr;
}