[code] Enumerate IE instances and retrieve interfaces.

[anonytmouse]

No problems, just thought this code may be of use to someone.

I wanted to enumerate open Internet Explorer windows and retrieve the corresponding COM interfaces. The standard solution, detailed in Q176792 only found 8 of the 30 ie windows I had opened. Fortunately, Active Accessibility provides another solution (detailed in Q249232). This code provides a function, EnumIEWindows(), that allows one to easily enumerate IE instances.

// Implementation 

#include <mshtml.h>
#include <oleacc.h>

typedef BOOL (CALLBACK * IEENUMPROC)(HWND hwnd, LPVOID pif, LPARAM lParam);

static BOOL CALLBACK EnumIEChildWindows(HWND hwnd, LPARAM lParam)
{
	TCHAR szClassName[100];

	if (GetClassName(hwnd, szClassName, 100) &&
	    lstrcmp(szClassName, TEXT("Internet Explorer_Server")) == 0)
	{
		*((HWND *) lParam) = hwnd;
		return FALSE;
	}

	return TRUE;
}

BOOL WINAPI EnumIEWindows(IEENUMPROC lpEnumFunc, REFIID riid, LPARAM lParam)
{
	HWND hwnd;
	HINSTANCE hInst;
	LPFNOBJECTFROMLRESULT pfObjectFromLresult;
	UINT uMsg     = RegisterWindowMessage(TEXT("WM_HTML_GETOBJECT"));

	if (!(hInst = LoadLibrary(TEXT("OLEACC.DLL"))))
	{
		// Active Accessibility is not available on this machine.
		// Windows 2000/XP have AA installed. It is available for other
		// platforms as a redistributable.
		return FALSE;
	}

	if (!(pfObjectFromLresult = (LPFNOBJECTFROMLRESULT) GetProcAddress(hInst, "ObjectFromLresult")))
	{
		FreeLibrary(hInst);
		return FALSE;
	}

	hwnd = FindWindowEx(NULL, NULL, TEXT("IEFrame"), NULL);

	while (hwnd != NULL)
	{
		HWND hwndChild = NULL;
		EnumChildWindows(hwnd, EnumIEChildWindows, (LPARAM) &hwndChild);

		if (hwndChild)
		{
			void * pif;
			LRESULT lr;
			HRESULT hr;
		
			if (SendMessageTimeout(hwndChild, uMsg, 0L, 0L, SMTO_ABORTIFHUNG, 1000, (DWORD_PTR *) &lr))
			{
				hr = pfObjectFromLresult(lr, riid, 0, &pif);

				if (SUCCEEDED(hr))
				{
					if (!lpEnumFunc(hwnd, pif, lParam)) break;
				}
			} // else document is not ready.
		}

		hwnd = FindWindowEx(NULL, hwnd, TEXT("IEFrame"), NULL);
	}

	FreeLibrary(hInst);
	return TRUE;
}

// Optional header file

#ifndef IEENUM_INCLUDED
#define IEENUM_INCLUDED
#include <objbase.h>
typedef BOOL (CALLBACK * IEENUMPROC)(HWND hwnd, LPVOID pif, LPARAM lParam);
BOOL WINAPI EnumIEWindows(IEENUMPROC lpEnumFunc, REFIID riid, LPARAM lParam);
#endif

// Sample usage

#include <mshtml.h>
#include <exdisp.h>

BOOL CALLBACK EnumIEWindowsProc(HWND hwnd, LPVOID pif, LPARAM lParam)
{
	IHTMLDocument2 * pDoc = (IHTMLDocument2 *) pif;
	BSTR bstr = NULL;
	VARIANT vt;


	// -- Manipulate document object. --

	pDoc->get_URL(&bstr);
	MessageBoxW(NULL, bstr, NULL, 0);
	SysFreeString(bstr);

	V_VT(&vt)   = VT_BSTR;
	V_BSTR(&vt) = SysAllocString(L"yellow");
	pDoc->put_bgColor(vt);
	VariantClear(&vt);


	// -- Shows how to get parent window. --
	
	IHTMLWindow2 * pWindow = NULL;

	pDoc->get_parentWindow(&pWindow);
	if (pWindow)
	{
		bstr = SysAllocString(L"Hello World");
		pWindow->alert(bstr);
		SysFreeString(bstr);
		pWindow->Release();
	}


	// -- Shows how to get parent web browser (See Q172763). --
	
	IWebBrowser2 * pBrowser  = NULL;
	IServiceProvider * psp   = NULL;

	pDoc->QueryInterface(IID_IServiceProvider, (void **) &psp);
	if (psp)
	{
		psp->QueryService(IID_IWebBrowserApp, IID_IWebBrowser2, (void **) &pBrowser);
		if (pBrowser)
		{
			pBrowser->get_LocationName(&bstr);
			MessageBoxW(NULL, bstr, NULL, 0);
			SysFreeString(bstr);
			pBrowser->Release();
		}

		psp->Release();
	}

	// Generic release of pif.
	((IUnknown *) pif)->Release();

	// Return true to conntinue enumeration.
	return TRUE;
}


int main(void)
{
	CoInitialize(NULL);

	if (!EnumIEWindows(EnumIEWindowsProc, IID_IHTMLDocument2, 0))
	{
		MessageBox(NULL, TEXT("Active Accessibility is not installed. Please install Active Accessibility."),
		           TEXT("Fatal Error"), MB_ICONSTOP);
		return GetLastError();
	}

	CoUninitialize();
	return 0;
}

[Fordy]

I've been messing with some VC++/COM stuff recently...

Here's another stab at enumerating Internet Explorer references but using some of VC++'s IDispatch wrapper abilities

#include <iostream>
#include <string>
#include <windows.h>
#include <comip.h>	
#include <comdef.h>

//Paths to system dlls containing the interfaces we need
#import "C:\WINDOWS\system32\shell32.DLL"
#import "C:\WINDOWS\system32\SHDOCVW.DLL" 

struct COM_INIT_ //Get COM ready
{
	COM_INIT_(){CoInitialize(0);}
	~COM_INIT_(){CoUninitialize();}
}COMINIT;


int main(int argc, char *argv[])
{
	try
	{
		SHDocVw::IShellWindowsPtr lpIWins; //Shell Windows Enumeration
		SHDocVw::IWebBrowser2Ptr lpIWeb; //WebBrowser/InternetExplorer Interface
		Shell32::IShellDispatchPtr lpIShell; //Shell.Application Object
		
		lpIShell.CreateInstance(L"Shell.Application");	//Create a Shell.Application Object

		lpIWins = lpIShell->Windows();	//Get references to all shell windows

		for(LONG i = 0;i < lpIWins->Count;++i)
		{			
			//For each Shell Window check if it's using http for the protocol
			//If so it's acting as a web browser, so show the URL
			lpIWeb = lpIWins->Item(i);	
			if(std::string(lpIWeb->GetLocationURL()).substr(0,4) == "http") 
			{
                std::cout << static_cast<char*>(lpIWeb->GetLocationURL()) << std::endl;
			}
		}
		std::cout << "Success";
	}
	catch(_com_error& e)
	{		
		std::cout << "Com Error - " << e.ErrorMessage();
	}
}