如何识别网页选择中的不同元素？

• 下载源代码文件 - 1.41 Kb
• 下载演示项目 - 159 Kb

引言

首先，我获取浏览器组件的 IHTMLDocument2 接口，然后获取该接口的 selection 属性以获取 IHTMLSelectionObject 接口。现在到了困难的部分，实际解析这些内容。我假设如果我能够使用 createRange 方法为所选内容创建一个控制范围，那么我就能够获得一个列表，其中 HTML 标签及其属性会整齐地分隔开。

现在，使用 IMarkupServices，我可以enum 网页浏览器所选部分的全部元素。以下是代码

//File:IESelection.CPP

#include <afxwin.h>
#include <afxdisp.h>

#include <atlbase.h>
//You may derive a class from CComModule and use it
//if you want to override
//something, but do not change the name of _Module
extern CComModule _Module;
#include <atlcom.h>

///
#include <mshtml.h>
#include <MsHtmcid.h>

///
HRESULT GetMarkupServices(IDispatch *pDocument, 
        IMarkupServices ** pMarkupServices );
HRESULT EnumSelectionElements(IDispatch *pDocument, CString &msg);

HRESULT PrintElement(IHTMLElement *pElement, CString &msg);
///
HRESULT EnumSelectionElements(IDispatch * pDocument, CString &msg)
{
    HRESULT                         hr     = S_OK;
    CComQIPtr<IHTMLDOCUMENT2>       pDoc;
    CComQIPtr<IHTMLSELECTIONOBJECT> pSel;
    CComQIPtr<IHTMLTXTRANGE>        pRange;
    CComQIPtr<IMARKUPSERVICES>      pMarkupServices;
    CComQIPtr<IMARKUPPOINTER>       pHtmlStart;
    CComQIPtr<IMARKUPPOINTER>       pHtmlEnd;
    CComQIPtr<IHTMLELEMENT>         pElement;
    CComBSTR                        bstrTagName;
   BOOL                            bRight = FALSE;
    CComBSTR                        bstrinnerText;
   
   ///
   msg = L"";

   ///
    if( ! (pDoc = pDocument) )
      return E_FAIL;
   
    hr = pDoc->get_selection( & pSel );
    if (hr || (!pSel) )
        return E_FAIL;
   
    hr = pSel->createRange((IDispatch **)&pRange);
    if (hr || (!pRange))
        return E_FAIL;
   
    hr = GetMarkupServices(pDocument, &pMarkupServices);
    if (hr || (!pMarkupServices) )
        return E_FAIL;
   
    hr = pMarkupServices->CreateMarkupPointer( &pHtmlStart );
    if (hr || (!pHtmlStart) )
        return E_FAIL;
   
    hr = pMarkupServices->CreateMarkupPointer( &pHtmlEnd );
    if (hr || (!pHtmlEnd))
        return E_FAIL;
   
    hr = pMarkupServices->MovePointersToRange( pRange, 
         pHtmlStart, pHtmlEnd );
    if (hr)
        return E_FAIL;
   
   ///
    while (TRUE)
    {
      pElement = (IUnknown*)NULL;

      hr = pHtmlStart->IsRightOf(pHtmlEnd, &bRight);
      if( hr )
         return E_FAIL;
      if( bRight )
         break;

      hr = pHtmlStart->CurrentScope( &pElement );
      if (hr)
         return E_FAIL;
      hr = pElement->get_tagName( &bstrTagName );
      if (hr)
         return E_FAIL;
      hr = pElement->get_innerText( &bstrinnerText);
      if (hr)
         return E_FAIL;
      //   
      CString ele_msg;
      PrintElement( pElement, ele_msg);
      
      msg += ele_msg;

      //move to next element
      hr = pHtmlStart->MoveUnit(MOVEUNIT_NEXTBLOCK);
      if (hr)
         return E_FAIL;
   }
   
   return S_OK;
}

HRESULT GetMarkupServices(IDispatch *pDocument, 
        IMarkupServices ** pMarkupServices)
{
    CComQIPtr<IHTMLDOCUMENT2>    pDoc;
    CComQIPtr<IHTMLWINDOW2>      pWindow;
    CComQIPtr<ISERVICEPROVIDER>  pService;
    HRESULT                      hr = S_OK;
   
    pDoc = pDocument;
   if( ! pDoc)
      return E_FAIL;

    hr = pDoc->get_parentWindow( &pWindow );
    if (hr)
      return E_FAIL;
   
    pService = pWindow;
    if ( !pService )
      return E_FAIL;
   
    hr = pService->QueryService( CLSID_HTMLDocument,
      IID_IMarkupServices,
      (void **) pMarkupServices);
    if (hr)
      return E_FAIL;
   return S_OK;
}

////////////////////////////////////////
HRESULT PrintElement(IHTMLElement *pElement, CString &msg)
{
   CComQIPtr<IHTMLIMGELEMENT>  pImg( pElement );
   CComBSTR  bstrTagName;
   CComBSTR  bstrinnerText;
   CComBSTR  bstrSrc;
   HRESULT   hr = S_OK;
   
   hr = pElement->get_tagName( &bstrTagName );
   if (FAILED(hr))
      return hr;
   hr = pElement->get_innerText( &bstrinnerText);
   if (FAILED(hr))
      return hr;
   if( pImg )
   {
      hr = pImg->get_src( &bstrSrc );
      if (FAILED(hr))
         return hr;
   }
   //
   CString ele_msg;
   ele_msg.Format("tagName=%S", bstrTagName);
   if( bstrinnerText.Length())
   {
      ele_msg += ",innerText=";
      ele_msg += CString(bstrinnerText);
   }
   if( bstrSrc.Length())
   {
      ele_msg += ",src=";
      ele_msg += CString(bstrSrc);
   }
   ele_msg += "\n";

   //enum childres
   CComQIPtr<IHTMLELEMENTCOLLECTION> pAll;
   hr = pElement->get_all( (IDispatch**)& pAll );
   if (FAILED(hr))
      return hr;

   long count = 0;
   hr = pAll->get_length( & count );
   if (FAILED(hr))
      return hr;
   for(long i=0; i<COUNT; CComQIPtr<IDispatch index(i); 
          CComVariant { i++)> pdisp;
          CComQIPtr<IHTMLELEMENT> pitem;
          hr = pAll->item( index, index, & pdisp );
        if (FAILED(hr))
           return hr;
      //
      pitem = pdisp;
      if( !pitem )
         continue;
      PrintElement( pitem, ele_msg);
      //
   }
   //
   msg += ele_msg;
   //
   TRACE0( ele_msg );
   return S_OK;
}