如何在VC环境下编写程序读取XML文件?清提供源代码.谢谢.

#import <msxml3.dll> named_guids //导入动态库，装了IE5就有
using namespace MSXML2; //引用命名空间，一般可以把命名空间理解成类和接口的集合，呵呵，对不对我也不知道了
#include <vector>
using namespace std;
struct FIELD
{
public:
CString name;
CString type;
CString length;
CString explain;
CString allowNull;
CString autoIncrease;
};
class Xml
{
public:
Xml(void);
~Xml(void);
private:
HRESULT hr;
MSXML2::IXMLDOMDocumentPtr pDoc; //XML文档接口指针
public:
void AddKey(CString moduleName,CString keyName, CString keyValue);
CString ReadKeyValue(CString moduleName, CString keyName);
private:
void NewDocument(CString moduleName, CString keyName, CString keyValue);
public:
bool ReadTable(CTreeCtrl * tree);
bool ReadFields(CString tableName,vector<FIELD> &fields);
bool SaveTable(vector<FIELD> fields,CString tableName,bool bNew);
};

//-------------------------------------------------------------------------------------------------------------------------------------

上面是头文件，这是cpp文件

#include "StdAfx.h"
#include "xml.h"

Xml::Xml(void)
{

CoInitialize(NULL); //初始化COM
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMDocument,(void**)&pDoc); //创建XML文档实例
}

Xml::~Xml(void)
{
CoUninitialize();
}

void Xml::AddKey(CString moduleName,CString keyName, CString keyValue)
{
CString selectString="AppSetting/"+moduleName; //XML节点定位字符串，定位到节点名为moduleName的二级节点,根节点取默认名为"AppSetting"
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMDocument,(void**)&pDoc); //创建文档实例
CFileFind finder; //查找文件是否存在的MFC类
if(!finder.FindFile("Config.xml")) //查找文件是否存在，不存在则调用函数生成一个新的XML文件
{
NewDocument(moduleName,keyName,keyValue);
return;
}
pDoc->load("Config.xml"); //从应用程序目录中加载XML文件
MSXML2::IXMLDOMNodePtr moduleNode; //XML节点接口指针
MSXML2::IXMLDOMNodePtr keyNode; //同上
MSXML2::IXMLDOMNodePtr selectNode; //同上
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMNode,(void**)&moduleNode); //创建节点实例
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMNode,(void**)&keyNode); //同上
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMNode,(void**)&selectNode); //同上
moduleNode=pDoc->selectSingleNode((_bstr_t)selectString); //定位到节点名为moduleName的二级节点
if(moduleNode==NULL) //如果无法定位，说明还不存在此节点，生成一个新的节点
{
selectNode=pDoc->selectSingleNode("AppSetting"); //定位到根节点，这里一定能定位成功，除非手动改了XML文件
moduleNode=pDoc->createNode(1,(_bstr_t)moduleName,""); //生成新节点
selectNode->appendChild(moduleNode); //将新节点添加到根节点
}
selectString+="/"+keyName; //XML节点定位字符串，定位到节点名为keyName的三级节点
keyNode=pDoc->selectSingleNode((_bstr_t)selectString); //定位到节点名为keyName的三级节点
if(keyNode==NULL) //如果无法定位，说明还不存在此节点，生成一个新的节点
{
keyNode=pDoc->createNode(1,(_bstr_t)keyName,""); //生成新节点
moduleNode->appendChild(keyNode); //将新节点添加到节点名moduleName的节点
}
keyNode->text=(_bstr_t)keyValue; //给节点名为keyName的节点赋text值秋keyValue
pDoc->save("Config.xml"); //保存
}

CString Xml::ReadKeyValue(CString moduleName, CString keyName)
{
CString selectString="AppSetting/"+moduleName+"/"+keyName;
CString keyValue="";
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMDocument,(void**)&pDoc); //创建文档实例
CFileFind finder; //查找文件是否存在的MFC类
if(!finder.FindFile("Config.xml")) //查找文件是否存在，不存在则调用函数生成一个新的XML文件
{
return "";
}
pDoc->load("Config.xml");
MSXML2::IXMLDOMNodePtr selectNode; //同上
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMNode,(void**)&selectNode); //创建节点实例
selectNode=pDoc->selectSingleNode((_bstr_t)selectString);
if(selectNode==NULL)
{
return "";
}
else
{
return (CString)((BSTR)selectNode->text);
}
}

void Xml::NewDocument(CString moduleName, CString keyName, CString keyValue)
{
CString strXml="<AppSetting><"+moduleName+"><"+keyName+">"+keyValue+"</"+keyName+"></"+moduleName+"></AppSetting>"; //XML字符串
pDoc->loadXML((_bstr_t)strXml); //通过加载字符生成XML的Document,此处用方法loadXml,从文件加载用load，参考前面
pDoc->save("Config.xml"); //保存
}

bool Xml::ReadTable(CTreeCtrl * tree)
{
CString selectString="DataResource/Tables/Table";
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMDocument,(void**)&pDoc); //创建文档实例
CFileFind finder; //查找文件是否存在的MFC类
if(!finder.FindFile("DataResource.xml")) //查找文件是否存在，不存在则调用函数生成一个新的XML文件
{
return false;
}
pDoc->load("DataResource.xml");
MSXML2::IXMLDOMElementPtr node; //同上
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMElement,(void**)&node); //创建节点实例
MSXML2::IXMLDOMNodeListPtr selectNodes;
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMNodeList,(void**)&selectNodes);//创建节点列表实例
selectNodes=pDoc->selectNodes((_bstr_t)selectString); //查找节点集

HTREEITEM tabItem=tree->GetChildItem(tree->GetRootItem());
if(selectNodes==NULL)
{
return false;
}
else
{
for(long i=0;i<selectNodes->Getlength();i++)
{

node=selectNodes->Getitem(i);
_variant_t nodeName=node->getAttribute("Name");

tree->InsertItem((CString)nodeName.bstrVal,3,3,tabItem);
}

//return (CString)((BSTR)selectNode->text);
}
return true;
}
bool Xml::ReadFields(CString tableName,vector<FIELD> &fields)
{

CString selectString="DataResource/Tables/Table";
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMDocument,(void**)&pDoc); //创建文档实例
CFileFind finder; //查找文件是否存在的MFC类
if(!finder.FindFile("DataResource.xml")) //查找文件是否存在，不存在则调用函数生成一个新的XML文件
{
return false;
}
pDoc->load("DataResource.xml");
MSXML2::IXMLDOMElementPtr node; //同上
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMElement,(void**)&node); //创建节点实例
MSXML2::IXMLDOMNodeListPtr tableNodes;
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMNodeList,(void**)&tableNodes);//创建节点列表实例
MSXML2::IXMLDOMNodeListPtr fieldNodes;
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMNodeList,(void**)&fieldNodes);//创建节点列表实例
tableNodes=pDoc->selectNodes((_bstr_t)selectString); //查找节点集

if(tableNodes==NULL)
{
return false;
}
for(long i=0;i<tableNodes->Getlength();i++)
{
node=tableNodes->Getitem(i);
CString nodeName=(CString)node->getAttribute("Name");
if(nodeName==tableName)
{
fieldNodes=node->GetchildNodes();
break;
}
}
if(fieldNodes==NULL)
{
return false;
}
fields.clear();
for(long i=0;i<fieldNodes->Getlength();i++)
{
FIELD field;
node=fieldNodes->Getitem(i);
field.autoIncrease=node->getAttribute("AutoIncrease");
field.explain=node->getAttribute("Explain");
field.length=node->getAttribute("Length");
field.name=node->getAttribute("Name");
field.type=node->getAttribute("Type");
field.allowNull=node->getAttribute("AllowNull");
fields.push_back(field);

}
return true;
}
bool Xml::SaveTable(vector<FIELD> fields,CString tableName,bool bNew)
{

hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMDocument,(void**)&pDoc); //创建文档实例
CFileFind finder; //查找文件是否存在的MFC类
if(!finder.FindFile("DataResource.xml")) //查找文件是否存在，不存在则调用函数生成一个新的XML文件
{
return false;
}
pDoc->load("DataResource.xml");
CString selectString="";
selectString="DataResource/Tables";
MSXML2::IXMLDOMNodePtr tablesNode;
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMNode,(void**)&tablesNode); //创建节点实例
MSXML2::IXMLDOMElementPtr tableNode; //同上
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMElement,(void**)&tableNode); //创建节点实例
tablesNode=pDoc->selectSingleNode((_bstr_t)selectString); //查找节点集
if(bNew)
{
tableNode=pDoc->createNode(1,"Table","");
tableNode->setAttribute("Name",(_bstr_t)tableName);
}
else
{
MSXML2::IXMLDOMNodeListPtr tableNodeList;
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMNodeList,(void**)&tableNodeList); //创建节点列表实例
tableNodeList=tablesNode->GetchildNodes();
CString nodeName="";
for(int i=0;i<tableNodeList->Getlength();i++)
{
tableNode=tableNodeList->Getitem(i);
nodeName=tableNode->getAttribute("Name");
if(nodeName.MakeLower()==tableName.MakeLower())
{
MSXML2::IXMLDOMElementPtr fieldNode; //同上
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMElement,(void**)&fieldNode); //创建节点实例
int fieldsCount=tableNode->GetchildNodes()->Getlength();
for(int j=fieldsCount-1;j>-1;j--)
{
fieldNode=tableNode->GetchildNodes()->Getitem(j);
tableNode->removeChild(fieldNode);
}
break;
}
if(i==tableNodeList->Getlength())
{
return false;
}
}
}
for(int i=0;i<fields.size();i++)
{
MSXML2::IXMLDOMElementPtr fieldNode; //同上
hr=CoCreateInstance(MSXML2::CLSID_DOMDocument,NULL,CLSCTX_ALL,MSXML2::IID_IXMLDOMElement,(void**)&fieldNode); //创建节点实例
fieldNode=pDoc->createNode(1,"Field","");
FIELD field=fields[i];
fieldNode->setAttribute("Name",(_bstr_t)field.name);
fieldNode->setAttribute((_bstr_t)"AllowNull",(_bstr_t)field.allowNull);
fieldNode->setAttribute((_bstr_t)"AutoIncrease",(_bstr_t)field.autoIncrease);
fieldNode->setAttribute((_bstr_t)"Explain",(_bstr_t)field.explain);
fieldNode->setAttribute((_bstr_t)"Length",(_bstr_t)field.length);
fieldNode->setAttribute((_bstr_t)"Type",(_bstr_t)field.type);
tableNode->appendChild(fieldNode);
}
if(bNew)
tablesNode->appendChild(tableNode);
pDoc->save("DataResource.xml");
return true;
}

//下面是另外的一段代码
{
// TODO: Add your implementation code here
CComPtr<xml::IXMLDOMDocument> pDoc;

try
{
HRESULT hr = pDoc.CoCreateInstance(L"Msxml2.DOMDocument.4.0");
if (FAILED(hr)) return hr;

CComPtr<xml::IXMLDOMElement> pRoot;
hr = pDoc->get_documentElement(&pRoot);
if (FAILED(hr)) return hr;

//create comment
CComPtr<xml::IXMLDOMComment> pComm;
hr=pDoc->createComment(CComBSTR(L"Compupacific Entry Template"),&pComm);
if (FAILED(hr)) return hr;
hr=pDoc->appendChild(pComm,0);

//Root of the Doc
CComPtr<xml::IXMLDOMElement> pElem;
hr = pDoc->createElement(CComBSTR(L"Template"), &pElem);
if (FAILED(hr)) return hr;

hr = pDoc->putref_documentElement(pElem);
if (FAILED(hr)) return hr;

VARIANT var;
var.vt=VT_BSTR;
var.bstrVal=::SysAllocString(m_bstrCaption);
hr = pElem->setAttribute(CComBSTR(L"Name"), var);
::SysFreeString(var.bstrVal);
if (FAILED(hr)) return hr;

VARIANT var1;
var1.vt=VT_BSTR;
var1.bstrVal=::SysAllocString(m_bstrSampleImage);
hr = pElem->setAttribute(CComBSTR(L"Sample"), var1);
::SysFreeString(var1.bstrVal);
if (FAILED(hr)) return hr;

VARIANT var2;
var2.vt=VT_I2;
var2.iVal=m_shDock;
hr = pElem->setAttribute(CComBSTR(L"Dock"), var2);
if (FAILED(hr)) return hr;
}
catch(...)
{
::MessageBox(NULL,_T("Error in save form property!"),_T("Error Report"),MB_OK);
return S_FALSE;
}
try
{
//Now tell the form to persist its child controls
CComBSTR Tmp;
for(std::list<CAxWindowHandle* >::iterator it = m_listSites.begin(); it != m_listSites.end();it++)
{
if(*it)
{
CComPtr<xml::IXMLDOMElement> pRoot;
HRESULT hr = pDoc->get_documentElement(&pRoot);
if (FAILED(hr)) return hr;

CComPtr<xml::IXMLDOMNode> pNode;
Tmp=OLESTR("Control");
CComBSTR Tmp1;
hr = pDoc->createNode(CComVariant(1),Tmp.m_str, Tmp1.m_str, &pNode);
if (FAILED(hr)) return hr;

hr = pRoot->appendChild(pNode.p, 0);
if (FAILED(hr)) return hr;

CComPtr<IPersistPropertyBag> spPersistPropBag;
hr = (*it)->QueryControl(&spPersistPropBag);
if (FAILED(hr)) return hr;

hr = spPersistPropBag->InitNew();
if (FAILED(hr)) return hr;

CComPtr<IPersistPropertyBag> spExtendedPPB;
if((*it)->m_pExtendedDispatchObj)
{
hr = (*it)->m_pExtendedDispatchObj->QueryInterface(&spExtendedPPB);
if (FAILED(hr)) return hr;
}

CComQIPtr<xml::IXMLDOMElement> pElem(pNode);
if(!pElem) return E_NOINTERFACE;

//Save Extended Properties
hr = SaveToXML(pDoc, pElem.p, spExtendedPPB, TRUE, TRUE);
if (FAILED(hr)) return hr;

//Save Native Properties
hr = SaveToXML(pDoc, pElem.p, spPersistPropBag, TRUE, TRUE);
if (FAILED(hr)) return hr;
}
}

return pDoc->save(CComVariant(FileName));
}
catch(...)
{
::MessageBox(NULL,_T("Error in save control property!"),_T("Error Report"),MB_OK);
return S_FALSE;
}
}