如何为 web 浏览器控制主机处理脚本错误

http://support.microsoft.com/kb/261003

当其中一个脚本引擎遇到未处理的错误时，它将转发到 web 浏览器控件，然后查询以查看容器已经实现了宿主其容器的错误。如果容器已实现宿主，web
浏览器控件调用CGID_DocHostCommandHandler （这在 Mshtmhst.h 文件中定义） 的命令组 ID 和OLECMDID_SHOWSCRIPTERROR的命令 ID 的IOleCommandTarget::Exec方法。如果主机不会返回S_OK，MSHTML 显示默认的"此页上出现错误"错误信息。

下面的代码演示如何实现文档对象模型中检索信息时此命令 id 的处理程序。此代码不会说明了错误处理。

注： 如果用户已清除在 Internet 选项 下的 高级 选项卡中的 禁用脚本调试 复选框，将不会调用此方法。

STDMETHODIMP CMyBrowser::Exec( const GUID* pguidCmdGroup, DWORD nCmdID,
      DWORD nCmdexecopt, VARIANTARG* pvaIn, VARIANTARG* pvaOut )
   {

      HRESULT hr = S_OK;

      if (pguidCmdGroup && IsEqualGUID(*pguidCmdGroup, CGID_DocHostCommandHandler))
      {
         
         switch (nCmdID) 
         {
         
         case OLECMDID_SHOWSCRIPTERROR:
         {
            IHTMLDocument2*             pDoc = NULL;
            IHTMLWindow2*               pWindow = NULL;
            IHTMLEventObj*              pEventObj = NULL;
            BSTR                        rgwszNames[5] = 
                                        { 
                                           SysAllocString(L"errorLine"),
                                           SysAllocString(L"errorCharacter"),
                                           SysAllocString(L"errorCode"),
                                           SysAllocString(L"errorMessage"),
                                           SysAllocString(L"errorUrl")
                                        };
            DISPID                      rgDispIDs[5];
            VARIANT                     rgvaEventInfo[5];
            DISPPARAMS                  params;
            BOOL                        fContinueRunningScripts = true;
            int	                        i;

            params.cArgs = 0;
            params.cNamedArgs = 0;

            // Get the document that is currently being viewed.
            hr = pvaIn->punkVal->QueryInterface(IID_IHTMLDocument2, (void **) &pDoc);				
            // Get document.parentWindow.
            hr = pDoc->get_parentWindow(&pWindow);
            pDoc->Release();
            // Get the window.event object.
            hr = pWindow->get_event(&pEventObj);
            // Get the error info from the window.event object.
            for (i = 0; i < 5; i++) 
            {  
               // Get the property's dispID.
               hr = pEventObj->GetIDsOfNames(IID_NULL, &rgwszNames[i], 1, 
                       LOCALE_SYSTEM_DEFAULT, &rgDispIDs[i]);
               // Get the value of the property.
               hr = pEventObj->Invoke(rgDispIDs[i], IID_NULL,
LOCALE_SYSTEM_DEFAULT,
                       DISPATCH_PROPERTYGET, ¶ms, &rgvaEventInfo[i],
NULL, NULL);
               SysFreeString(rgwszNames[i]);
            }

            // At this point, you would normally alert the user with 
            // the information about the error, which is now contained
            // in rgvaEventInfo[]. Or, you could just exit silently.

            (*pvaOut).vt = VT_BOOL;
            if (fContinueRunningScripts)
            {
               // Continue running scripts on the page.
               (*pvaOut).boolVal = VARIANT_TRUE;
            }
            else
            {
               // Stop running scripts on the page.
               (*pvaOut).boolVal = VARIANT_FALSE;			
            } 
            break;
         }
         default:
            hr = OLECMDERR_E_NOTSUPPORTED;
            break;
         }
      }
      else
      {
         hr = OLECMDERR_E_UNKNOWNGROUP;
      }
      return (hr);
   }

如何重写的 MFC 控件容器接口方法看这里：/article/2464172.html