UIAutomation not catching all elements

Question

Im using the code above to walk through the descendants of an element, however its not catching everything like i can see using inspect.exe.
inspect-objects

I'm testing in the chrome browser, in this current webpage, its catching just current opened pages, bookmarks, and browser buttons, its missing to catch the page content.

While testing in others windows like a folder for example, it does catch everything correctly, but its taking too much time, in a folder with 120 elements it takes up to 1.4 seconds, i wonder if the code could be improved in any manner?

WCHAR window[250] = L"Ask a question - Microsoft Q&A";  
IUIAutomationElement *element = GetTopLevelWindowByName(window);  
ListDescendants(element, 2);  
  
IUIAutomationElement* GetTopLevelWindowByName(LPWSTR windowName)  
{  
    if (windowName == NULL)  
        return NULL;  
  
	CComPtr<IUIAutomation> g_pAutomation;  
	if (SUCCEEDED(CoInitialize(NULL)))  
	{  
		if (!SUCCEEDED(g_pAutomation.CoCreateInstance(CLSID_CUIAutomation8))) // or CLSID_CUIAutomation  
			return NULL;  
	}  
  
    VARIANT varProp;  
    varProp.vt = VT_BSTR;  
    varProp.bstrVal = SysAllocString(windowName);  
    if (varProp.bstrVal == NULL)  
        return NULL;  
  
    IUIAutomationElement* pRoot        = NULL;  
    IUIAutomationElement* pFound       = NULL;  
    IUIAutomationCondition* pCondition = NULL;  
  
    // Get the desktop element.   
    HRESULT hr = g_pAutomation->GetRootElement(&pRoot);  
    if (FAILED(hr) || pRoot == NULL)  
        goto cleanup;  
  
    // Get a top-level element by name, such as "Program Manager"  
    hr = g_pAutomation->CreatePropertyCondition(UIA_NamePropertyId, varProp, &pCondition);  
    if (FAILED(hr))  
        goto cleanup;  
  
    pRoot->FindFirst(TreeScope_Children, pCondition, &pFound);  
  
cleanup:  
    if (pRoot != NULL)  
        pRoot->Release();  
  
    if (pCondition != NULL)  
        pCondition->Release();  
  
    VariantClear(&varProp);  
    return pFound;  
}  
  
  
  
void ListDescendants(IUIAutomationElement* pParent, int indent)  
{  
	static CComPtr<IUIAutomation> g_pAutomation;  
  
	if (!g_pAutomation) {  
		if (SUCCEEDED(CoInitialize(NULL)))  
		{  
			if (!SUCCEEDED(g_pAutomation.CoCreateInstance(CLSID_CUIAutomation8))) // or CLSID_CUIAutomation  
				return;  
		}  
	}  
  
  
	if (pParent == NULL)  
		return;  
  
	IUIAutomationTreeWalker* pControlWalker = NULL;  
	IUIAutomationElement* pNode = NULL;  
  
	g_pAutomation->get_ControlViewWalker(&pControlWalker);  
	if (pControlWalker == NULL)  
		goto cleanup;  
  
	pControlWalker->GetFirstChildElement(pParent, &pNode);  
	if (pNode == NULL)  
		goto cleanup;  
  
	while (pNode)  
	{  
		BSTR sName;  
		pNode->get_CurrentName(&sName);  
  
		UIA_HWND uia_hwnd;  
		pNode->get_CurrentNativeWindowHandle(&uia_hwnd);  
  
		RECT rect;  
		pNode->get_CurrentBoundingRectangle(&rect);  
  
		ListDescendants(pNode, indent + 1);  
		IUIAutomationElement* pNext;  
		pControlWalker->GetNextSiblingElement(pNode, &pNext);  
		pNode->Release();  
		pNode = pNext;  
	}  
  
cleanup:  
	if (pControlWalker != NULL)  
		pControlWalker->Release();  
  
	if (pNode != NULL)  
		pNode->Release();  
  
	return;  
}  

Answer 1

Perhaps page contents are not IUIAutomationElement nodes. It is a UI Automation document content client sample which can access the content of a document that is being displayed in another application's window.

Answer 2

Hello XiaopoYang, the source code compiles only in vs2012? no chance to compile in vs19?

Answer 3

You can get all the elements in the hierarchy with IUIAutomationElement::FindAll or IUIAutomationElement::FindAllBuildCache and TreeScope_Descendants
There are returned in an IUIAutomationElementArray array, so it is faster than IUIAutomationTreeWalker
If I test with Edge Chromium on this page, I get all the elements inside the page, like all your code