Freigeben über


onreadystatechange Event

 

Fires when the readyState method changes.

Inline HTML <ELEMENT onreadystatechange = "handler" ... > All platforms
Event property object.onreadystatechange = handler Microsoft® JScript® (compatible with ECMA 262 language specification) only
Named script <SCRIPT FOR = object EVENT = onreadystatechange> Microsoft Internet Explorer only

JScript Syntax

oXMLDOMDocument.onreadystatechange;  

Example

The following JScript and HTML example demonstrates the sequence of ready states when asynchronously loading a document.

<script>  
var xmldoc;  
function Load()  
{  
  xmldoc = new ActiveXObject("Msxml2.DOMDocument.6.0");  
  xmldoc.onreadystatechange = CheckState;  
  xmldoc.load(URL.value);  
}  
function CheckState()  
{  
  var state = xmldoc.readyState;  
  RESULTS.innerHTML += "readyState = " + state + "<BR>"  
  if (state == 4)  
  {  
    var err = xmldoc.parseError;  
    if (err.errorCode != 0)  
      RESULTS.innerHTML += err.reason + "<BR>"  
    else RESULTS.innerHTML +="success" + "<BR>"  
  }  
}  
</script>  
URL: <input type=text size=60 id=URL>  
<input type=button value=LOAD onclick="jscript:Load()">  
<div id=RESULTS style= "color:red;font-weight:bold;"></div>  

C/C++ Syntax

HRESULT onreadystatechange(void);  
C/C++ Return Values:  

Return Values

S_OK
The value returned if successful.

Example

BEGIN_DISPATCH_MAP(CXMLDOMSamples, CCmdTarget)  
   DISP_FUNCTION_ID(CXMLDOMSamples, "Ready State Event Handler",   
   DISPID_XMLDOMEVENT_ONREADYSTATECHANGE, DOMDocCheckState, VT_EMPTY, 0)  
END_DISPATCH_MAP()  
  
class CXMLDOMSamples : public CCmdTarget  
{  
private:  
   HRESULT m_hr;  
   IXMLDOMDocument* m_pIXMLDOMDocument;  
   BSTR m_bstrXMLDocName;  
   DWORD m_pdwCookie;  
public:  
   BOOL AdviseConnectionPoint(BOOL bAdvise = TRUE);  
   void Caller();  
   BOOL DOMDocLoadLocation();  
   BOOL DOMDocStateChangeSetup();  
   void DOMDocCheckState();  
};  
  
// Assumptions     
// m_pIXMLDOMDocument has already been initialized (a DOMDocument   
// object has been created).  
// Automation is enabled for the class to enable it to connect   
// to the Connection point (DIID_XMLDOMDocumentEvents).  
  
void CXMLDOMSamples::Caller()  
{  
   try  
   {  
   m_bstrXMLDocName = ::SysAllocString(_T("http://MyServer/sample.xml"));  
   DOMDocStateChangeSetup();  
   DOMDocLoadLocation();  
   ::SysFreeString(m_bstrXMLDocName);  
   m_bstrXMLDocName = NULL;  
}  
   catch(...)  
   {  
      if(m_bstrXMLDocName)  
      ::SysFreeString(m_bstrXMLDocName);  
      DisplayErrorToUser();  
   }   
}  
BOOL CXMLDOMSamples::AdviseConnectionPoint(BOOL bAdvise)  
{  
   BOOL bResult = FALSE;  
   try  
   {  
      IConnectionPointContainer *pIConnectionPointContainer = NULL;  
      IConnectionPoint *pCP = NULL;  
  
      m_hr = m_pIXMLDOMDocument->QueryInterface      
      (IID_IConnectionPointContainer,(void**)&pIConnectionPointContainer);  
      SUCCEEDED(m_hr) ? 0 : throw m_hr;  
  
      If(pIConnectionPointContainer)  
      {  
         m_hr = pIConnectionPointContainer->FindConnectionPoint   
               (DIID_XMLDOMDocumentEvents, &pCP);  
         SUCCEEDED(m_hr) ? 0 : throw m_hr;  
         if(SUCCEEDED(m_hr) && pCP)  
         {  
            if(bAdvise)  
               m_hr = pCP->Advise(GetIDispatch(TRUE), &m_pdwCookie);  
            else  
               m_hr = pCP->Unadvise(m_pdwCookie);  
            bResult = SUCCEEDED(m_hr) ? TRUE : FALSE;  
            pCP->Release();  
            pCP = NULL;  
         }  
         pIConnectionPointContainer->Release();  
         pIConnectionPointContainer = NULL;  
      }  
   }  
   catch(...)  
   {  
      if(pIConnectionPointContainer)  
         pIConnectionPointContainer->Release();  
      if(pCP)  
         pCP->Release();  
      DisplayErrorToUser();  
   }  
   return bResult;  
}  
BOOL CXMLDOMSamples::DOMDocStateChangeSetup()  
{  
   BOOL bResult = FALSE;  
   try  
   {  
      m_hr = m_pIXMLDOMDocument->put_async(VARIANT_TRUE);  
      SUCCEEDED(m_hr) ? 0 : throw m_hr;  
      bResult = AdviseConnectionPoint();  
   }  
   catch(...)  
   {  
      DisplayErrorToUser();  
   }  
   return bResult;  
}  
BOOL CXMLDOMSamples::DOMDocLoadLocation()  
{  
   short sResult = FALSE;  
   BOOL bResult = FALSE;  
   try  
   {  
      _variant_t varString = m_bstrXMLDocName;  
      m_hr = m_pIXMLDOMDocument->load(varString, &sResult);  
      bResult = SUCCEEDED(m_hr) ? TRUE : FALSE;  
   }  
   catch(...)  
   {  
      DisplayErrorToUser();  
   }  
   return bResult;  
}  
void CXMLDOMSamples::DOMDocCheckState()  
{  
   IXMLDOMParseError *pIParseError = NULL;  
   long value;  
  
   try  
   {  
      m_hr = m_pIXMLDOMDocument->get_readyState(&value);  
      SUCCEEDED(m_hr) ? 0 : throw m_hr;  
      if(value == 4 )  
      {  
         m_hr = m_pIXMLDOMDocument->get_parseError(&pIParseError);  
         SUCCEEDED(m_hr) ? 0 : throw m_hr;  
         m_hr = pIParseError->get_errorCode(&value);  
         pIParseError->Release();  
         pIParseError=NULL;  
         if(!SUCCEEDED(m_hr))  
         {  
            throw m_hr;  
         }  
         m_strOutput = (value != 0) ? _T("Load Error") : _T("Load   
            Succeeded");  
      }  
   }  
   catch(...)  
   {  
      if(pIParseError)  
         pIParseError->Release();  
      DisplayErrorToUser();  
   }  
}  

Remarks

This event can be explicitly set using the onreadystatechange property.

This member is an extension of the Worldwide Web Consortium (W3C) Document Object Model (DOM).

Versioning

Implemented in: MSXML 3.0 and MSXML 6.0

Applies to

IXMLDOMDocument-DOMDocument

See Also

onreadystatechange Property (DOMDocument)