To create an Internet browser, you must define a class for the browser that inherits OLE interfaces to facilitate OLE activation. The following table shows the interfaces that the class must inherit.
| Interface | Description |
|---|---|
| IOleContainer | This interface is used to enumerate objects in a compound document or to lock a container in the running state. Container and object applications both implement this interface. |
| IOleClientSite | This interface is the primary means by which an embedded object obtains information about the ___location and the extent of its display site, moniker, user interface, and other resources provided by its container. |
| IOleInPlaceSite | This interface manages interaction between the container and the object's in-place client site. The client site is the display site for embedded objects, and provides position and conceptual information about the object. |
| IOleControlSite | This interface provides the methods that enable a site object to manage each embedded control within a container. A site object provides this interface as well as other site interfaces such as IOleClientSite and IOleInPlaceSite. When a control requires the services expressed through this interface, it will query one of the other client site interfaces for IOleControlSite. |
| DWebBrowserEvents2 | This interface designates an event sink interface that an application must implement in order to receive event notifications from a WebBrowser control or from the Internet Explorer application. |
The following code example shows a browser class, CBrowser, that implements the browser object.
class CBrowser :
public IOleContainer,
public IOleClientSite,
public IOleInPlaceSite,
public IOleControlSite,
public DWebBrowserEvents2
{
public:
// Declare new and delete clear allocators.
inline void * __cdecl operator new(size_t cb) { return LocalAlloc(LPTR, cb); }
inline void __cdecl operator delete(void * pv) { LocalFree(pv); }
// Constructor and Destructor
CBrowser();
~CBrowser();
//IUnknown methods
STDMETHOD(QueryInterface) (REFIID riid, LPVOID * ppv)
{
//QueryInterface for IoleContainer.
if ((riid == IID_IOleContainer) || (riid == IID_IUnknown))
{
RETAILMSG(1, (L"Browser QueryInterface for IOleContainer"));
*ppv = (IOleContainer *) this;
}
else if (...//Inerface)
{
...//Query Interface for other interfaces.
}
AddRef();
return S_OK;
}
STDMETHOD_(ULONG, AddRef) (void)
{
...
}
STDMETHOD_(ULONG, Release) (void)
{
...
}
...// IOleContainer methods
...// IOleClientSite methods
...// IOleWindow methods
...// IOleInPlaceSite methods
...// IOleControlSite methods
...// DWebBrowserEvents
...// IDispatch methods
// public methods
HRESULT StartBrowser(LPWSTR szURL); // Start a browser.
HRESULT NavigateToURL(LPWSTR szURL); // Browse to a URL.
void CloseBrowser(); // Close the browser.
//static WndProc wrapper and actual WndProc
static LRESULT CALLBACK s_BrowseWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
LRESULT BrowseWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
private:
HRESULT CreateBrowserWindow(); // Create the main window.
HRESULT CreateBrowserObject(); // Create a web browser object.
HRESULT RegisterBrowserEventSink(); // Connect up the event sink
// private members
HWND _hWnd; //The main window
IoleObject *_pObject; // The browser object
IConnectionPoint *_pCP; // Pointer to the browser event connection-point (for DWebBrowserEvents2)
IWebBrowser2 *_pWB2; // Pointer to the Web browser object
BOOL _bInPlaceActive; // Determines if the document is active
DWORD _dwEventCookie; // Stores cookies that will be received when the
// browser registers to receive DWebBrowserEvents2
ULONG _ulRefs; //reference count for the interfaces supported by the
//container.
};
See Also
Registering the Browser Window | Creating an Internet Browser
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