如何运行我刚刚从BHO动态插入的<script>标记

Question

我非常擅长使用Browser Helper Objects开发IE扩展.

我设法创建了一个BHO,它成功地插入了一个脚本标记,该标记引用了HTML页面头部的javascript文件(参见下面的代码).

但是脚本标记只是位于DOM中,并且不执行外部javascript文件.

有没有办法告诉浏览器运行外部JavaScript文件？

谢谢!

代码详细信息: 我在OnDocumentComplete事件上调用以下方法:

void CHelloWorldBHO::InsertScriptTag(IDispatch* pDispDoc)
{
HRESULT hr = S_OK;
// query for an HTML document.
CComQIPtr<IHTMLDocument3> pDocument3 = pDispDoc;
CComQIPtr<IHTMLDocument2> pDocument2 = pDispDoc;
if (pDocument2 != NULL && pDocument3 != NULL)
{
    // **********************   create our script tag Element  (pHtmlElem) ****************************
    IHTMLElement* pHtmlElem;
    CComVariant vAlert="http://www.gnpcb.org/esv/share/js/?action=getDailyVerse"; // example referencing external JS code
    CComVariant vJavascript="text/javascript";
    hr = pDocument2->createElement(_T("script"), &pHtmlElem); 
    if (SUCCEEDED(hr) && pHtmlElem != NULL)
    {
        hr = pHtmlElem->setAttribute(_T("type"), vJavascript); 
        hr = pHtmlElem->setAttribute(_T("src"), vAlert);            
    }

    // **********************   insert Element  (pHtmlElem) in HTML Head ****************************
    // Get the head from the DOM.
    static const CComBSTR sbstrHead(L"head");
    CComPtr<IHTMLElementCollection> objects;
    hr = pDocument3->getElementsByTagName(sbstrHead, &objects);
    if(SUCCEEDED(hr) && objects != NULL)
    {
        // Get the number of elements in the collection.
        long nElements = 0;
        hr = objects->get_length(&nElements);
        if (hr == S_OK && nElements > 0)
        {
            CComVariant svarItemIndex(0); // we will get the first element
            CComVariant svarEmpty;
            CComPtr<IDispatch> spdispElement;

            // Get the element out of the collection with index 0 (the first element, that is, the head)
            hr = objects->item(svarItemIndex, svarEmpty, &spdispElement);
            if (hr == S_OK && spdispElement != NULL)
            {
                CComQIPtr<IHTMLDOMNode, &IID_IHTMLDOMNode> spHeadNode = spdispElement; // query for DOM interfaces
                CComQIPtr<IHTMLDOMNode, &IID_IHTMLDOMNode> spNodeNew; 
                spNodeNew = pHtmlElem; 

                if (spHeadNode)
                {
                    spHeadNode->appendChild(spNodeNew, NULL); 
                }
            }
        }
    }
}

}

Answer 1

您应该使用execScript而不是appendChild.你需要执行的语法是非常非常奇怪的.但它完成了你想要的 - 即,一个外部JavaScript被添加到DOM.在OnDocumentComplete期间调用此方法:

VARIANT vrt = {0};
CComQIPtr<IHTMLWindow2> win;
spHTMLDoc->get_parentWindow(&win);
CComBSTR bstrScript = L"var html_doc = document.getElementsByTagName('head')[0]; var _js = document.createElement('script');  _js.setAttribute('type', 'text/javascript'); _js.setAttribute('id', 'bho_js'); _js.setAttribute('src', 'http://domain.com/script.js'); if(!document.getElementById('bho_js')) html_doc.appendChild(_js);";
CComBSTR bstrLanguage = L"javascript";
HRESULT hrexec = win->execScript(bstrScript,bstrLanguage, &vrt);

这将添加<script type="text/javascript" id="bho_js" src="http://domain.com/script.js"></script>到DOM HEAD中.