ATL & DHTML

Leesen

I write an ATL control to implement the onunload event of the html. I set the onunload handle through IHTMLBodyElement. But it did not work. Source code as follow: //definition of IDHTMLTest2 in IDL interface IDHTMLTest2 : IDispatch { [id(1), helpstring("method ShowMsg")] HRESULT ShowMsg(); }; //selection of the source code CComPtrspIE; m_spClientSite->GetContainer(&spIE); CComQIPtrspDoc(spIE); if (spDoc){ CComPtr spElement; spDoc->get_body(&spElement); CComQIPtr spBody(spElement); IDispatch* pShowMsg; QueryInterface(IID_IDHTMLTest2,(void**)&pShowMsg); VARIANT v; v.vt=VT_DISPATCH; v.pdispVal=pShowMsg; //this event can't be invoke ,when close the ie-window spBody->put_onunload(v); //this invoke works well ((IDHTMLTest2*)pShowMsg)->ShowMsg(); //code below can works well // v.vt=VT_BSTR; // v.bstrVal = L"#DA70D6"; // spBody->put_bgColor(v); } Thank you for your advanced help. Regards.

Peter Molnar

If I were to decide, this code should work. Some remarks: 1.Shouldn't you write

CComQIPtr<IID_IHTMLBodyElement> spBody(spElement); //CComQIPtr spBody(spElement);

Otherwise how does QI know wich interface to query for? Same with spDoc. 2.I would reccomend you to use smart dispatch pointer: IDispatchPtr. This way you don't have the trouble with QI and releasing it. 3.Since

spBody->put_bgColor(v); //and
((IDHTMLTest2*)pShowMsg)->ShowMsg();

seem to work, the problem should be with "v" or put_onunload. Maybe 2. will solve the issue? Eventuelly you could try a CComVariant on "v". 4.What if setting with spElement's setAttribute onunload=ExitFunction, additionally inserting the ExitFunction with an alert? Peter Molnar

Leesen

I have tried by your advice. But it sitll not work. And I set the default method. [id(0), helpstring("method Prompt")] HRESULT ShowMsg(); The DHTML will invoke the default method with DISPID=0; It still not work. Have you any source code which can run smoothly .Could you send me for reference ? Thank You. Email: fengrux@hotmail.com

Peter Molnar

The last resort I see is to implement 4./ For this you will have to insert another attribute into the body tag with the name onunload. you have two choices:

or

Your code:

spElement->setAttribute(CComBSTR("onunload"),CComVariant("\"alert('This is my onunload message!')\""),0);

or

spElement->insertAdjacentHTML(CComBSTR("beforeBegin"),CComBSTR("...the entire script tag..."));
spElement->setAttribute(CComBSTR("onunload"),CComVariant("ExitFunction()"),0);

Peter Molnar

Leesen

You mean insert code in the HTML ?? My intention is to fire the Event in the ActiveX control . Thus , web designer without konwing about the Activex can simply using "" tag to deploy the ActiveX.

Peter Molnar

Yes, you should definitly insert code into the HTML. Of course this is not the HTML the user of your ActiveX creates but the HTML your ActiveX "perceives" of the user's HTML code or "thinks" the user wrote. All this has the aim to fire the onunload event. You know: the aim justifies the means... Peter Molnar

ATL &amp; DHTML

ATL & DHTML