创建和自动化Internet Explorer和资源管理器窗口
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我在很久之前就开始用程序自动化Shell窗口——主要对象是IE窗口。有时浏览器控件或者MFC类CHTMLView可以满足我的需要，但是很多时候我需要从头嵌入浏览器控件并且尽可能模拟IE的行为，例如实现IDocHostUIHandler来启用自动完成功能。一个很自然的替代方案是直接操作IE窗口。
创建新的Internet Explorer窗口
最简单的方法是调用Windows API ShellExecute (Ex)，Paul DiLascia在他的C++ Q&A专栏文章"Browser Detection Revisited, Toolbar Info, IUnknown with COM and MFC"里面有一段示例代码:
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/// As I've shown in many programs...
ShellExecute(
0
, _T(
"
open
"
), pszMyHTMLFile,
0
,
0
, SW_SHOWNORMAL);
但是，这样没法控制新的窗口，而且在用户关闭程序之后会留下一个IE窗口。为了扫我自己的门前雪，我需要找到我创建的窗口，并且控制它。我的下一个尝试是创建和控制一个InternetExplorer对象，并且在必要时关掉它。微软知识库中有这么一篇文章"How To Automate Internet Explorer to POST Form Data" 基本上描述的就是我想要的，除了最后的关闭窗口。嗯，简单的调用IWebBrowser2::Quit就可以做到这一点
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-->
//
create a new IE instance and show it
//
CComQIPtr m_pWebBrowser2;
m_pWebBrowser2.CoCreateInstance(CLSID_InternetExplorer); HRESULT hr; hr
=
m_pWebBrowser2
->
put_StatusBar(VARIANT_TRUE); hr
=
m_pWebBrowser2
->
put_ToolBar(VARIANT_TRUE); hr
=
m_pWebBrowser2
->
put_MenuBar(VARIANT_TRUE); hr
=
m_pWebBrowser2
->
put_Visible(VARIANT_TRUE);
if
(
!
::PathIsURL(m_strFileToFind)) m_strFileToFind
=
_T(
"
http://blog.joycode.com/jiangsheng
"
); COleVariant vaURL( ( LPCTSTR) m_strFileToFind); m_pWebBrowser2
->
Navigate2(
&
vaURL, COleVariant( (
long
)
0
, VT_I4), COleVariant((LPCTSTR)NULL, VT_BSTR), COleSafeArray(), COleVariant((LPCTSTR)NULL, VT_BSTR) );
void
CAutomationDlg::OnDestroy()
{ //close the IE window created by this program before exit if(m_pWebBrowser2) { if(m_bOwnIE) { m_pWebBrowser2->Quit(); m_bOwnIE=FALSE; } UnadvisesinkIE(); m_pWebBrowser2=(LPUNKNOWN)NULL; } CDialog::OnDestroy(); }
还有一个问题。要是用户在我的WM_TIMER处理函数中操作窗口之前关掉了新的IE窗口怎么办？可以IWebBrowser2接口控制的IE对象现在不再存在了。幸亏微软考虑到了这一点，程序不会崩溃，但是最好还是能够知道什么时候它会关闭，这样我可以避免意外发生。 处理Internet Explorer的事件
Internet Explorer对象在退出时会触发DWebBrowserEvents2::OnQuit事件。这是一个理想的释放控制的时机。因为对象要被销毁，所以我同时也停止监视对象的事件
连接到当前的Internet Explorer窗口<!-- Code highlighting produced by Actipro CodeHighlighter (freeware) http://www.CodeHighlighter.com/ --> if (m_pWebBrowser2) { UnadvisesinkIE(); m_pWebBrowser2=(LPUNKNOWN)NULL; }
虽然我不在乎我会控制到哪个IE窗口，但是既然微软知识库里面有"如何连接到一个Internet Explorer的实例"这样一篇文章，我假定一些人会觉得"如何连接到当前的Internet Explorer实例"这样一篇文章比较有用.
这样的话，什么是“当前的Internet Explorer实例”？实际上，它就是最后一个活动的IE窗口。因为Windows会把活动的窗口移动到z-order的顶部，所以它会保留在所有IE窗口的z-order的最高处。因此我需要做的就是找到哪个IE窗口具有最高的z-order值。这样我需要先判断哪个窗口是IE窗口。在一些和Spy++有关的调查之后，我假定IE窗口具有一个共同的窗口类"IEFrame"，然后编写了一个函数来获得Shell窗口的窗口类：
剩下的问题就很简单了：沿Z轴枚举顶层窗口，找到第一个Shell窗口列表中的具有窗口类"IEFrame"的第一个实例。之后我操作了一下IE的DHTML文档对象模型(也称为DOM，它只在IE窗口触发最后一个DocumentComplete事件只后有效)来确认成功连接到窗口。<!-- Code highlighting produced by Actipro CodeHighlighter (freeware) http://www.CodeHighlighter.com/ --> // shell windows object will list both IE and Explorer windows // use their window class names to identify them. CString CAutomationDlg::GetWindowClassName(IWebBrowser2 * pwb) { TCHAR szClassName[_MAX_PATH]; ZeroMemory( szClassName, _MAX_PATH * sizeof( TCHAR)); HWND hwnd=NULL; if (pwb) { LONG_PTR lwnd=NULL; pwb->get_HWND(&lwnd); hwnd=reinterpret_cast(lwnd); ::GetClassName( hwnd, szClassName, _MAX_PATH); } return szClassName; }
现在控制的窗口和IE打开文件时选择的一样了。<!-- Code highlighting produced by Actipro CodeHighlighter (freeware) http://www.CodeHighlighter.com/ --> void CAutomationDlg::DocumentComplete(IDispatch * pDisp, VARIANT * URL) { //HTML DOM is available AFTER the DocumentComplete event is fired. //For more information, please visit KB article //"How To Determine When a Page Is Done Loading in WebBrowser Control" //http://support.microsoft.com/kb/q180366/ CComQIPtr pWBUK(m_pWebBrowser2); CComQIPtr pSenderUK( pDisp); USES_CONVERSION; TRACE( _T( "Page downloading complete:/r/n")); CComBSTR bstrName; m_pWebBrowser2->get_LocationName(&bstrName); CComBSTR bstrURL; m_pWebBrowser2->get_LocationURL(&bstrURL); TRACE( _T( "Name:[ %s ]/r/nURL: [ %s ]/r/n"), OLE2T(bstrName), OLE2T(bstrURL)); if (pWBUK== pSenderUK) { CComQIPtr pHTMLDocDisp; m_pWebBrowser2->get_Document(&pHTMLDocDisp); CComQIPtr pHTMLDoc(pHTMLDocDisp); CComQIPtr ecAll; CComPtr pTagLineDisp; if(pHTMLDoc) { CComBSTR bstrNewTitle(_T("Sheng Jiang's Automation Test")); pHTMLDoc->put_title(bstrNewTitle); pHTMLDoc->get_all(&ecAll); } if(ecAll) { ecAll->item(COleVariant(_T("tagline")),COleVariant((long)0),&pTagLineDisp); } CComQIPtr eTagLine(pTagLineDisp); if(eTagLine) { eTagLine->put_innerText( CComBSTR(_T("Command what is yours, conquer what is not. --Kane"))); } } }
副产品: 连接到当前的Windows Explorer窗口
在研究ShellWindows对象的shell窗口列表时，我获得一个副产品：看起来Windows Explorer窗口也有共同的窗口类名。这样同样的机制在把窗口类从"IEFrame"改成"ExploreWClass"之后对Windows Explorer窗口也适用。因为没有DHTML DOM可供操作，我通知Windows Explorer 窗口打开一个现存路径，来标志我接管了这个窗口。
这代码有点长，因为我想区别对待文件和文件夹。如果你调用IShellBrowser::BrowseObject并且给这个方法传递一个文件pidl，那么Windows Explorer会提示你是否打开这个文件，就像在资源管理器的地址栏中输入路径之后按回车一样。我想模拟"Explorer.exe /select"的行为，在文件夹视图中选择指定的文件，所以我在DocumentComplete事件处理函数中加入了一些代码：<!-- Code highlighting produced by Actipro CodeHighlighter (freeware) http://www.CodeHighlighter.com/ --> // show the folder bar COleVariant clsIDFolderBar(_T( " {EFA24E64-B078-11d0-89E4-00C04FC9E26E} " )); COleVariant FolderBarShow(VARIANT_TRUE,VT_BOOL); COleVariant dummy; if (m_pWebBrowser2) m_pWebBrowser2 -> ShowBrowserBar( & clsIDFolderBar, & FolderBarShow, & dummy); // browse to a given folder CComQIPtr psp(m_pWebBrowser2); CComPtr psb; if (psp) psp -> QueryService(SID_STopLevelBrowser,IID_IShellBrowser,(LPVOID * ) & psb); if (psb) { USES_CONVERSION; LPITEMIDLIST pidl=NULL; SFGAOF sfgao; SHParseDisplayName (T2OLE(m_strFileToFind),NULL,&pidl,0, &sfgao); if(pidl==NULL) ::SHGetSpecialFolderLocation(m_hWnd,CSIDL_DRIVES,&pidl); m_pidlToNavigate=NULL; if(pidl) { //if the start address is a folder, then browse it. //otherwise browse to its parent folder, and select it in the folder view. LPCITEMIDLIST pidlChild=NULL; CComPtr psf; HRESULT hr = SHBindToParent(pidl, IID_IShellFolder, (LPVOID*)&psf, &pidlChild); if (SUCCEEDED(hr)){ SFGAOF rgfInOut=SFGAO_FOLDER; hr=psf->GetAttributesOf(1,&pidlChild,&rgfInOut); if (SUCCEEDED(hr)){ m_pidlToNavigate=ILClone(pidl); if(rgfInOut&SFGAO_FOLDER){//this is a folder psb->BrowseObject(pidl,SBSP_SAMEBROWSER); } else { //this is a file, browse to the parent folder LPITEMIDLIST pidlParent=ILClone(pidl); ::ILRemoveLastID(pidlParent); psb->BrowseObject( pidlParent, SBSP_SAMEBROWSER); ILFree(pidlParent); } } } //clean up ILFree(pidl); } } :
创建Explorer窗口<!-- Code highlighting produced by Actipro CodeHighlighter (freeware) http://www.CodeHighlighter.com/ --> if (m_pidlToNavigate) { //If the start address is a file, browse to the parent folder //and then select it CComQIPtr psp(m_pWebBrowser2); CComPtr psb; CComPtr psv; if(psp) psp->QueryService(SID_STopLevelBrowser,IID_IShellBrowser,(LPVOID*)&psb); if(psb) psb->QueryActiveShellView(&psv); if(psv) { LPCITEMIDLIST pidlChild=NULL; CComPtr psf; SFGAOF rgfInOut=SHCIDS_ALLFIELDS; HRESULT hr = SHBindToParent(m_pidlToNavigate, IID_IShellFolder, (LPVOID*)&psf, &pidlChild); if (SUCCEEDED(hr)){ hr=psf->GetAttributesOf(1,&pidlChild,&rgfInOut); if (SUCCEEDED(hr)){ if((rgfInOut&SFGAO_FOLDER)==0){ //a file, select it hr=psv->SelectItem(ILFindLastID(m_pidlToNavigate) ,SVSI_SELECT|SVSI_ENSUREVISIBLE|SVSI_FOCUSED| SVSI_POSITIONITEM); } } } } //clean up ILFree(m_pidlToNavigate); m_pidlToNavigate=NULL; }
解决了这么多问题，可以衣锦还乡了。既然我可以以和当前的Internet Explorer窗口基本相同的方式连接到当前的Windows Explorer窗口，那么我是否可以以和创建Internet Explorer窗口基本相同的方式创建Windows Explorer窗口？遗憾的是，这不可行。不存在Windows Explorer对应的类ID来创建一个COM对象。虽然我仍旧可以创建IE窗口，浏览到文件夹，显示文件夹侧边栏，使得它看起来就像一个Windows Explorer窗口，但是我不能改变窗口类"IEFrame"，因此较难把它和其他的显示HTML网页和活动文档的IE窗口区分开来。
好吧，既然我不能以COM的方式来创建它，我还可以尝试用传统的方式。我可以创建一个explorer.exe进程之后查找其主窗口，就像Paul DiLascia 在他的文章"Get the Main Window, Get EXE Name"中演示的那样，并且发送未文档化的消息WM_GETISHELLBROWSER来获得窗口的IShellBrowser接口:
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-->
//
start the new process
STARTUPINFO si; PROCESS_INFORMATION pi; ZeroMemory(
&
si,
sizeof
(si) ); si.cb
=
sizeof
(si); ZeroMemory(
&
pi,
sizeof
(pi) );
//
Start the child process.
if
(
!
CreateProcess( NULL,
//
No module name (use command line).
_T(
"
explorer.exe
"
),
//
Command line.
NULL,
//
Process handle not inheritable.
NULL,
//
Thread handle not inheritable.
FALSE,
//
Set handle inheritance to FALSE.
0
,
//
No creation flags.
NULL,
//
Use parent's environment block.
NULL,
//
Use parent's starting directory.
&
si,
//
Pointer to STARTUPINFO structure.
&
pi )
//
Pointer to PROCESS_INFORMATION structure.
)
//
wait a graceful time
//
so the window is created and is ready to answer messages.
::WaitForInputIdle(pi.hProcess,
1000
);
//
m_hExplorerProcess=(DWORD)pi.hProcess;
EnumWindows(EnumWindowsProc,(LPARAM)
this
); BOOL CALLBACK CAutomationDlg::EnumWindowsProc(HWND hwnd,LPARAM lParam)
{ CAutomationDlg* pdlg=(CAutomationDlg*)lParam; DWORD pidwin; GetWindowThreadProcessId(hwnd, &pidwin); if (pidwin==pdlg->m_hExplorerProcess) { IShellBrowser* psb=(IShellBrowser*)::SendMessage(hwnd,WM_USER+7,0,0); CComQIPtr pwb(psb); return FALSE; } return TRUE; }
啊喔，这在我的计算机上也没有效果。怎么回事？在我的资源管理器的文件夹选项中，“在同一窗口中打开每一个文件夹”被选中，所以新的Windows Explorer窗口被创建在现有的Windows Explorer进程中。看起来这是条死胡同。等一下，我手头还有另一个ShellWindows对象，它可以给我一个Shell窗口的列表，包含每一个Windows Explorer窗口和每个窗口对应的IWebBrowser2接口，这是到IShellBrowser接口的入口。.现在我需要获得两份shell窗口列表，创建explorer.exe进程之前和之后各一份，之后要比较它们来找到新的shell窗口：
等一下，你的"创建explorer.exe进程之后"是什么意思?一秒钟之后？还是两秒钟？实际上，一个WindowRegistered事件会被ShellWindows 对象触发，所以我在事件处理中加入一些代码：.<!-- Code highlighting produced by Actipro CodeHighlighter (freeware) http://www.CodeHighlighter.com/ --> m_pShellWindows.CoCreateInstance(CLSID_ShellWindows); if (m_pShellWindows) { //get the list of running IE windows //using the ShellWindows collection //For more information, please visit //http://support.microsoft.com/kb/176792 long lCount=0; m_pShellWindows->get_Count(&lCount); for(long i=0;i pdispShellWindow; m_pShellWindows->Item(COleVariant(i),&pdispShellWindow); if(pdispShellWindow) { m_listShellWindows.AddTail(new CComQIPtrIDispatch(pdispShellWindow)); } } } // enumerate through the new shell window list long lCount = 0 ; m_pShellWindows -> get_Count( & lCount); for ( long i = 0 ;i // search the new window // using the ShellWindows collection // For more information, please visit // http://support.microsoft.com/kb/176792 BOOL bFound = FALSE; CComPtr pdispShellWindow; m_pShellWindows -> Item(COleVariant(i), & pdispShellWindow); // search it in the old shell window list POSITION pos = m_listShellWindows.GetHeadPosition(); while (pos) { CComQIPtrIDispatch* pDispatch=m_listShellWindows.GetNext(pos); if(pDispatch&&pdispShellWindow.p==pDispatch->p) { bFound=TRUE;break; } } if ( ! bFound) // new window found { //attach to it m_pWebBrowser2=pdispShellWindow; m_bOwnIE=TRUE; //sink for the Quit and DocumentComplete events AdviseSinkIE(); NavigateToSamplePage(FALSE); } }
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//
sink DShellWindowsEvents events
LPUNKNOWN pUnkSink
=
GetIDispatch(FALSE); m_pShellWindows.CoCreateInstance(CLSID_ShellWindows); AfxConnectionAdvise((LPUNKNOWN)m_pShellWindows, DIID_DShellWindowsEvents,pUnkSink,FALSE,
&
m_dwCookieShellWindows);
void
CAutomationDlg::WindowRegistered(
long
lCookie)
{ //ok, a new shell window is created if(m_pShellWindows) { //enumerate through the new shell window list long lCount=0; m_pShellWindows->get_Count(&lCount); for(long i=0;i//search the new window //using the ShellWindows collection //For more information, please visit //http://support.microsoft.com/kb/176792 BOOL bFound=FALSE; CComPtr pdispShellWindow; m_pShellWindows->Item(COleVariant(i),&pdispShellWindow); //search it in the old shell window list POSITION pos=m_listShellWindows.GetHeadPosition(); while(pos) { CComQIPtrIDispatch* pDispatch=m_listShellWindows.GetNext(pos); if(pDispatch&&pdispShellWindow.p==pDispatch->p) { bFound=TRUE;break; } } if(!bFound)//new window { //attach to it m_pWebBrowser2=pdispShellWindow; m_bOwnIE=TRUE; //sink for the Quit and DocumentComplete events AdviseSinkIE(); NavigateToSamplePage(FALSE); } } //clean up if(m_dwCookieShellWindows!= 0) { LPUNKNOWN pUnkSink = GetIDispatch(FALSE); AfxConnectionUnadvise((LPUNKNOWN)m_pShellWindows, DIID_DShellWindowsEvents, pUnkSink, FALSE, m_dwCookieShellWindows); m_dwCookieShellWindows= 0; } POSITION pos=m_listShellWindows.GetHeadPosition(); while(pos) { CComQIPtrIDispatch* pDispatch=m_listShellWindows.GetNext(pos); delete pDispatch; } m_listShellWindows.RemoveAll(); m_pShellWindows=(LPUNKNOWN)NULL; }
}
为什么不用Browser Helper Objects?因为新的窗口在进程外，所以跨进程列集COM调用很慢。如果你的自动化操作包含很多的COM调用，那么你可能要把代码本地化，例如编写一个浏览器辅助对象(BHO)。但是，BHO会被每一个Windows Explorer和Internet Explorer的实例加载，而且我不想拖慢整个系统来让它们扫瓦上霜。一些人倒是使用了这个技术连接到当前的Internet Explorer窗口.
已知问题
ShellWindows对象在explorer.exe process被终止或者尚未启动时不可访问。BHO在这种情况下可以作为替代方案。
结论
这里有一大堆让人迷糊的代码，而且可能还有你不熟悉的COM和Windows API函数混合调用。希望你会觉得本文有用，并且不会被我的代码搞得头昏脑胀。自动化Internet Explorer和Windows Explorers窗口可以节省你模拟系统默认行为的时间，并且给用户提供一个熟悉的界面。
参考
- Browser Detection Revisited, Toolbar Info, IUnknown with COM and MFC
- Connecting to Running Instances of Internet Explorer
- Connecting to a running instance of Internet Explorer
- Get the Main Window, Get EXE Name
- How to connect to a running instance of Internet Explorer
- How to Connect to IExplorer in Citrix Environments
- PRB: IShellFolder::CreateViewObject() causes access violation
- Querying information from an Explorer window
- ShellWindows Object (Windows Explorer and Controls)
历史
- October 20, 2005 初版发布