VC入门宝典十一(xml)

                                         xml

                                                  何志丹

我们建立一个xml文件,内容如图所示:

一,建立一个基于对话框的程序,工程名为xml;

二, 初始化OLE.

BOOL CXmlApp::InitInstance()

{

         AfxOleInit();

…….

}

三, 在对话框中增加一个按钮,ID为IDC_CREATE,我们在这个按钮的响应函数中生成一个xml文件.

void CXmlDlg::OnCreate()

{

         MSXML2::IXMLDOMDocumentPtr pDoc;

         MSXML2::IXMLDOMElementPtr  xmlRoot ;

         //创建DOMDocument对象

         HRESULT hr = pDoc.CreateInstance(__uuidof(MSXML2::DOMDocument30));

         if(!SUCCEEDED(hr))

         {               

                   MessageBox("无法创建DOMDocument对象，请检查是否安装了MS XML Parser 运行库!");

         }

         //根节点的名称为china

         pDoc->raw_createElement((_bstr_t)(char*)"china", &xmlRoot);

         pDoc->raw_appendChild(xmlRoot, NULL);

         MSXML2::IXMLDOMElementPtr  childNode ;        

         pDoc->raw_createElement((_bstr_t)(char*)"City", &childNode);

         childNode->Puttext("WuHan");//节点值

         childNode->setAttribute("population","8,000,000");//属性名,属性值

         childNode->setAttribute("area","10000");

         xmlRoot->appendChild(childNode);

         pDoc->raw_createElement((_bstr_t)(char*)"City", &childNode);

         childNode->Puttext("ShangHai");

         childNode->setAttribute("population","12,000,000");

         childNode->setAttribute("area","12000");

         xmlRoot->appendChild(childNode);

         //保存到文件

         //如果不存在就建立,存在就覆盖

         pDoc->save("f:\\he.xml");

}

不要忘了#import "msxml4.dll" //引入类型库

四, 再增加一个按钮,ID为IDC_GET,在这个按钮的响应函数中读取xml文件.

void CXmlDlg::OnGet()

{

         //创建DOMDocument对象

         MSXML2::IXMLDOMDocumentPtr pDoc;

         HRESULT hr = pDoc.CreateInstance(__uuidof(MSXML2::DOMDocument30));

         if(!SUCCEEDED(hr))

         {               

                   MessageBox("无法创建DOMDocument对象，请检查是否安装了MS XML Parser 运行库!");

         }

         //加载文件

         pDoc->load("f:\\he.xml");

         //在树中查找名为City的节点,"//"表示在任意一层查找

         MSXML2::IXMLDOMElementPtr  childNode ;

         childNode = (MSXML2::IXMLDOMElementPtr)(pDoc->selectSingleNode("//City"));

         //得到节点类型

         MSXML2::DOMNodeType nodeType;

         childNode->get_nodeType(&nodeType);

         //节点名称

         BSTR var;

         CString name;

         childNode->get_nodeName(&var);

         name = (char*)(_bstr_t)var;

         //节点值

         VARIANT varVal;

         childNode->get_nodeTypedValue(&varVal);

         CString strValue = (char*)(_bstr_t)varVal;

         //节点属性,放在链表中

         MSXML2::IXMLDOMNamedNodeMapPtr pAttrs = NULL;

         MSXML2::IXMLDOMNodePtr pAttrItem;

         childNode->get_attributes(&pAttrs);

         long nCount ;

         pAttrs->get_length(&nCount);

         for(int i = 0 ; i < nCount ; i++)

         {                

                   pAttrs->get_item(i,&pAttrItem);

                   //我们可以通过函数get_nodeName,get_nodeTypedValue得到属性名和属性值

                   //也可以直接得到

                   CString strAttrName   = (char*)(_bstr_t)pAttrItem->nodeName;

                   CString strAttrValue  = (char*)(_bstr_t)pAttrItem->nodeTypedValue;

         }

}