很早之前我写过一篇Blog：网页通过External接口与WebBrowser交互，文中的交互其实只介绍了JS调用C++的部分，而C++调用JS由于微软自己的例子太多，那篇文章就没介绍，不过我最近遇到了一个新问题，和C++调用JS有关，所以重新梳理了下这块的逻辑，把之前的代码完善了下。
我遇到的问题：
内嵌IE浏览器控件WebBrowser的内嵌页host.html中使用iframe又嵌套了一个页面iframe.html，iframe.html上有个JS方法，我用C++调用不到，而host.html上的JS方法可以正常调用到。
问题分析：
从JS来说，这是个跨域问题，host.html和iframe.html不在一个域内；
JS解决跨域问题的方案其实也是有的，但这个不是我们本文的重点，本文的重点是怎么通过WebBrowser控件直接来解决这个“跨域调用”的问题。
问题的根本原因在于：
调用网页的JS需要拿到IHTMLDocument2接口，而每个iframe都有自己对应的IHTMLDocument2，所以我们只要能拿到iframe对应的IHTMLDocument2就能解决问题了。
解决方案：直接上代码吧
/* -------------------------------------------------------------------------
// FileName : calljs_helper.h
// Creator : linyehui
// Date : 2013/11/16 01:18:09
// Brief : 调用WebBrowser控件内嵌页上的JS函数，iframe中的也能调到
//
// $Id: $
// -----------------------------------------------------------------------*/
#ifndef __CALLJS_HELPER_H__
#define __CALLJS_HELPER_H__ // -------------------------------------------------------------------------
namespace calljs_helper
{
bool CallFunction(
CComPtr<IWebBrowser2> spIWebBrowser,
LPCTSTR lpFuncName,
const vector<wstring>& paramArray,
CComVariant * pVarResult = NULL,
bool bEnumFrame = true); } // namespace // -------------------------------------------------------------------------
// $Log: $ #endif /* __CALLJS_HELPER_H__ */
/* -------------------------------------------------------------------------
// FileName : calljs_helper.cpp
// Creator : linyehui
// Date : 2013/11/16 01:18:14
// Brief : 调用WebBrowser控件内嵌页上的JS函数，iframe中的也能调到
//
// $Id: $
// -----------------------------------------------------------------------*/ #include "stdafx.h"
#include "calljs_helper.h" // ------------------------------------------------------------------------- CComPtr<IWebBrowser2> HtmlWindowToHtmlWebBrowser(CComPtr<IHTMLWindow2> spWindow)
{
ATLASSERT(spWindow != NULL);
CComQIPtr<IServiceProvider> spServiceProvider = spWindow;
if (spServiceProvider == NULL)
{
return CComPtr<IWebBrowser2>();
} CComPtr<IWebBrowser2> spWebBrws;
HRESULT hRes = spServiceProvider->QueryService(IID_IWebBrowserApp, IID_IWebBrowser2, (void**)&spWebBrws);
if (hRes != S_OK)
{
return CComPtr<IWebBrowser2>();
} return spWebBrws;
} // Converts a IHTMLWindow2 object to a IHTMLDocument2. Returns NULL in case of failure.
// It takes into account accessing the DOM across frames loaded from different domains.
CComPtr<IHTMLDocument2> HtmlWindowToHtmlDocument(CComPtr<IHTMLWindow2> spWindow)
{
ATLASSERT(spWindow != NULL);
CComPtr<IHTMLDocument2> spDocument;
HRESULT hRes = spWindow->get_document(&spDocument);
if ((S_OK == hRes) && (spDocument != NULL))
{
// The html document was properly retrieved.
return spDocument;
} // hRes could be E_ACCESSDENIED that means a security restriction that
// prevents scripting across frames that loads documents from different internet domains.
CComPtr<IWebBrowser2> spBrws = HtmlWindowToHtmlWebBrowser(spWindow);
if (spBrws == NULL)
{
return CComPtr<IHTMLDocument2>();
} // Get the document object from the IWebBrowser2 object.
CComPtr<IDispatch> spDisp;
hRes = spBrws->get_Document(&spDisp);
spDocument = spDisp;
return spDocument;
} bool CallFunctionInDocument(
CComPtr<IHTMLDocument2> spDocument2,
LPCTSTR lpFuncName,
const vector<wstring>& paramArray,
CComVariant * pVarResult)
{
if (!spDocument2)
return false; CComPtr<IDispatch> spScript;
if (FAILED(spDocument2->get_Script(&spScript))) { return false; } CComBSTR bstrMember(lpFuncName);
DISPID dispid = NULL;
HRESULT hr = spScript->GetIDsOfNames(IID_NULL, &bstrMember, , LOCALE_SYSTEM_DEFAULT, &dispid);
if (FAILED(hr)) { return false; } const int arraySize = paramArray.size(); DISPPARAMS dispparams;
memset(&dispparams, , sizeof dispparams);
dispparams.cArgs = arraySize;
dispparams.rgvarg = new VARIANT[dispparams.cArgs]; for (int i = ; i < arraySize; i++)
{
CComBSTR bstr = paramArray[arraySize - - i].c_str(); // back reading
bstr.CopyTo(&dispparams.rgvarg[i].bstrVal);
dispparams.rgvarg[i].vt = VT_BSTR;
}
dispparams.cNamedArgs = ; EXCEPINFO excepInfo;
memset(&excepInfo, , sizeof excepInfo);
CComVariant vaResult;
UINT nArgErr = (UINT)-; // initialize to invalid arg hr = spScript->Invoke(dispid, IID_NULL, , DISPATCH_METHOD, &dispparams, &vaResult, &excepInfo, &nArgErr); delete [] dispparams.rgvarg;
if (FAILED(hr)) { return false; } if (pVarResult) { *pVarResult = vaResult; } return true;
} void EnumFrame(
CComPtr<IHTMLDocument2> spIHTMLDocument2,
LPCTSTR lpFuncName,const vector<wstring>& paramArray,
CComVariant* pVarResult)
{
if ( !spIHTMLDocument2 )
return; CComPtr< IHTMLFramesCollection2 > spFramesCollection2;
spIHTMLDocument2->get_frames( &spFramesCollection2 ); long nFrameCount=;
HRESULT hr = spFramesCollection2->get_length( &nFrameCount );
if ( FAILED ( hr ) || == nFrameCount )
return; for(long i = ; i < nFrameCount; i++)
{
CComVariant vDispWin2;
hr = spFramesCollection2->item( &CComVariant(i), &vDispWin2 );
if ( FAILED ( hr ) )
continue; CComQIPtr< IHTMLWindow2 > spWin2 = vDispWin2.pdispVal;
if( !spWin2 )
continue; CComPtr < IHTMLDocument2 > spDoc2;
spDoc2 = HtmlWindowToHtmlDocument(spWin2);
if (!spDoc2)
continue; CallFunctionInDocument(spDoc2, lpFuncName, paramArray, pVarResult);
}
} bool calljs_helper::CallFunction(
CComPtr<IWebBrowser2> spIWebBrowser,
LPCTSTR lpFuncName,
const vector<wstring>& paramArray,
CComVariant * pVarResult,
bool bEnumFrame)
{
if (!spIWebBrowser)
return false; CComPtr<IDispatch> spDispDoc;
HRESULT hr = spIWebBrowser->get_Document(&spDispDoc);
if (FAILED(hr))
return false; CComQIPtr<IHTMLDocument2> spDocument2 = spDispDoc;
if (!spDocument2)
return false; CallFunctionInDocument(spDocument2, lpFuncName, paramArray, pVarResult); if (bEnumFrame)
{
EnumFrame(spDocument2, lpFuncName, paramArray, pVarResult);
} return true;
} // -------------------------------------------------------------------------
// $Log: $
完整的例子代码在：这里下载
另外再附上帮助我解决问题的参考资料:
[http://blog.csdn.net/skyremember/article/details/3422841 IHTMLWindow2的get_document方法有时候会返回E_ACCESSDENIED]
[http://blog.csdn.net/nvidiacuda/article/details/9300869 VC++实现浏览器自动填表]
[http://www.itdelphi.com/delphibbs/doc/2007/3845499.htm webbrowser控件的IHTMLDocument3 or2接口的iframe问题（非安全设置）]
[http://www.cnblogs.com/rainman/archive/2011/02/21/1960044.html window.name实现的跨域数据传输]
[http://www.cnblogs.com/rainman/archive/2011/02/20/1959325.html JavaScript跨域总结与解决办法]
The End.