假如已存在一个xml文件classfile.xml

#import "msxml3.dll"
using namespace MSXML2;
void CannilyxmlDlg::OnBnClickedButton1()
{
 // TODO: 在此添加控件通知处理程序代码
 MSXML2::IXMLDOMDocumentPtr xmldoc;
 HRESULT hr;
 hr = CoInitialize(NULL);//必须初始化，否则后面的CreateInstance创建文档要失败
 if(FAILED (hr))//此处最好用FAILED或者SUCCEEDED来判断，否则可能引起未知错误
 {
  MessageBox("初始化COM失败");
 }
 else
 {
  MessageBox("初始化COM成功");
 }
 hr = xmldoc.CreateInstance(__uuidof(MSXML2::DOMDocument));
 if(FAILED (hr))
 {
  MessageBox("创建xml文档对象失败");
 }
 else
 {
  MessageBox("创建xml文档对象成功");
 }
 xmldoc->load("classfile.xml");//此语句非常非常重要，和解析xml字符串语句只有点点区别，但引起的错误却是千差万别
 MSXML2::IXMLDOMElementPtr root;
 MSXML2::IXMLDOMNodeListPtr nodelist;
 MSXML2::IXMLDOMNodeListPtr childnodelist;
 root = xmldoc->GetdocumentElement();
 nodelist = root->GetchildNodes();
 MSXML2::IXMLDOMNodePtr node;
 MSXML2::IXMLDOMNodePtr childnode;
 for(int i=0;i<nodelist->length;i++)
 {
  node = nodelist->Getitem(i);
  childnodelist = node->GetchildNodes();
  for(int j=0;j<childnodelist->length;j++)
  {
   childnode = childnodelist->Getitem(i);
   MessageBox(childnode->Gettext());
  }
 }
 ::CoUninitialize();
}

#import "msxml3.dll"
using namespace MSXML2;
void RealPlay(LPCTSTR msg)
{
 // TODO: 在此添加控件通知处理程序代码
 MSXML2::IXMLDOMDocumentPtr xmldoc;
 HRESULT hr;
 hr = CoInitialize(NULL);//必须初始化，否则后面的CreateInstance创建文档要失败
 if(FAILED (hr))//此处最好用FAILED或者SUCCEEDED来判断，否则可能引起未知错误
 {
  MessageBox("初始化COM失败");
 }
 else
 {
  MessageBox("初始化COM成功");
 }
 hr = xmldoc.CreateInstance(__uuidof(MSXML2::DOMDocument));
 if(FAILED (hr))
 {
  MessageBox("创建xml文档对象失败");
 }
 else
 {
  MessageBox("创建xml文档对象成功");
 }
 xmldoc->loadXML(msg);//此语句非常非常重要，和解析xml文件语句只有点点区别，但引起的错误却是千差万别
 MSXML2::IXMLDOMElementPtr root;
 MSXML2::IXMLDOMNodeListPtr nodelist;
 MSXML2::IXMLDOMNodeListPtr childnodelist;
 root = xmldoc->GetdocumentElement();
 nodelist = root->GetchildNodes();
 MSXML2::IXMLDOMNodePtr node;
 MSXML2::IXMLDOMNodePtr childnode;
 for(int i=0;i<nodelist->length;i++)
 {
  node = nodelist->Getitem(i);
  childnodelist = node->GetchildNodes();
  for(int j=0;j<childnodelist->length;j++)
  {
   childnode = childnodelist->Getitem(i);
   MessageBox(childnode->Gettext());
  }
 }
 ::CoUninitialize();
}