Which state I can invoke interface methods safely in BHO?

Question

I want to develop a tool for Web Automation test.

I write a BHO for obtaining the attributes of an element. such as text, position and so on.

but it sometimes cores dump when invoking some methods, for example, IHTMLElement->get_parentElement

if IWebBrowser2->Busy is VARIANT_FALSE and IHTMLDocument->readyState is complete, the dump never happens.

but it seems the verification is too strict. sometimes, some of web pages keep interactive state and the page seems normal. the operation will be blocked.

so how to call methods safely? is there any better ways?

Answer 1

Did you try to debug your tool, so that the cores dump

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NEU_ShieldEdge

Answer 2

yes. I debug.

dump happens when invoking some methods of the HTML object. but the object seems normal. only in different state.

Answer 3

I get some IHTMLElement objects and put them in the list.

then the page may refresh or load another page.

so the control does not exist but IHTMLElement objects in list still exist, not released.

when invoking their method, sometimes, it cores dump.