C# 里XML文件读写

已知有一个XML文件（bookstore.xml）如下：
<?xmlversion= "1.0"encoding= "gb2312"?>
<bookstore>
<bookgenre= "fantasy"ISBN= "2-3631-4">
<title>Oberon 'sLegacy</title>
<author>Corets,Eva</author>
<price>5.95</price>
</book>
</bookstore>
1、往<bookstore>节点中插入一个<book>节点：

XmlDocumentxmlDoc= newXmlDocument();
xmlDoc.Load( "bookstore.xml");
XmlNoderoot=xmlDoc.SelectSingleNode( "bookstore"); //查找<bookstore>
XmlElementxe1=xmlDoc.CreateElement( "book"); //创建一个<book>节点
xe1.SetAttribute( "genre", "李赞红"); //设置该节点genre属性
xe1.SetAttribute( "ISBN", "2-3631-4"); //设置该节点ISBN属性

XmlElementxesub1=xmlDoc.CreateElement( "title");
xesub1.InnerText= "CS从入门到精通"; //设置文本节点
xe1.AppendChild(xesub1); //添加到<book>节点中
XmlElementxesub2=xmlDoc.CreateElement( "author");
xesub2.InnerText= "候捷";
xe1.AppendChild(xesub2);
XmlElementxesub3=xmlDoc.CreateElement( "price");
xesub3.InnerText= "58.3";
xe1.AppendChild(xesub3);

root.AppendChild(xe1); //添加到<bookstore>节点中
xmlDoc.Save( "bookstore.xml");

//================
结果为：

<?xmlversion= "1.0"encoding= "gb2312"?>
<bookstore>
<bookgenre= "fantasy"ISBN= "2-3631-4">
<title>Oberon 'sLegacy</title>
<author>Corets,Eva</author>
<price>5.95</price>
</book>
<bookgenre= "李赞红"ISBN= "2-3631-4">
<title>CS从入门到精通</title>
<author>候捷</author>
<price>58.3</price>
</book>
</bookstore>

2、修改节点：将genre属性值为“李赞红“的节点的genre值改为“update李赞红”，将该节点的子节点<author>的文本修改为“亚胜”。

XmlNodeListnodeList=xmlDoc.SelectSingleNode( "bookstore").ChildNodes; //获取bookstore节点的所有子节点
foreach(XmlNodexn innodeList) //遍历所有子节点
{XmlElementxe=(XmlElement)xn; //将子节点类型转换为XmlElement类型
if(xe.GetAttribute( "genre")== "李赞红") //如果genre属性值为“李赞红”
{xe.SetAttribute( "genre", "update李赞红"); //则修改该属性为“update李赞红”

XmlNodeListnls=xe.ChildNodes; //继续获取xe子节点的所有子节点
foreach(XmlNodexn1 innls) //遍历
{XmlElementxe2=(XmlElement)xn1; //转换类型
if(xe2.Name== "author") //如果找到
{xe2.InnerText= "亚胜"; //则修改
break; //找到退出来就可以了
}}
break;
}}

xmlDoc.Save( "bookstore.xml"); //保存。

//=================

最后结果为：

<?xmlversion= "1.0"encoding= "gb2312"?>
<bookstore>
<bookgenre= "fantasy"ISBN= "2-3631-4">
<title>Oberon 'sLegacy</title>
<author>Corets,Eva</author>
<price>5.95</price>
</book>
<bookgenre= "update李赞红"ISBN= "2-3631-4">
<title>CS从入门到精通</title>
<author>亚胜</author>
<price>58.3</price>
</book>
</bookstore>

3、删除<bookgenre= "fantasy"ISBN= "2-3631-4">节点的genre属性，删除<bookgenre= "update李赞红"ISBN= "2-3631-4">节点。

XmlNodeListxnl=xmlDoc.SelectSingleNode( "bookstore").ChildNodes;

foreach(XmlNodexn inxnl)
{XmlElementxe=(XmlElement)xn;

if(xe.GetAttribute( "genre")== "fantasy")
{xe.RemoveAttribute( "genre"); //删除genre属性
} else if(xe.GetAttribute( "genre")== "update李赞红")
{xe.RemoveAll(); //删除该节点的全部内容
}}
xmlDoc.Save( "bookstore.xml");

//====================

最后结果为：

<?xmlversion= "1.0"encoding= "gb2312"?>
<bookstore>
<bookISBN= "2-3631-4">
<title>Oberon 'sLegacy</title>
<author>Corets,Eva</author>
<price>5.95</price>
</book>
<book>
</book>
</bookstore>

4、显示所有数据。

XmlNodexn=xmlDoc.SelectSingleNode( "bookstore");

XmlNodeListxnl=xn.ChildNodes;

foreach(XmlNodexnf inxnl)
{XmlElementxe=(XmlElement)xnf;
Console.WriteLine(xe.GetAttribute( "genre")); //显示属性值
Console.WriteLine(xe.GetAttribute( "ISBN"));

XmlNodeListxnf1=xe.ChildNodes;
foreach(XmlNodexn2 inxnf1)
{ Console.WriteLine(xn2.InnerText); //显示子节点点文本
}}
另有：
usingSystem;
usingSystem.IO;
usingSystem.Web;
usingSystem.Text;
usingSystem.Xml;
usingSystem.Collections;


namespaceShopWeb.Class
{ ///<summary>
///Log的摘要说明。
///</summary>
public classLog
{
privateXmlDocumentxmlLog= newXmlDocument();
privateHttpContextcontext=HttpContext.Current;
private stringxmlPath= "";
///<summary>
///构造函数
///</summary>
///<paramname="XmlPath"></param>
publicLog( stringXmlPath)
{

xmlPath=XmlPath;
xmlLog.Load(context.Server.MapPath(XmlPath));
}
///<summary>
///增加一个节点，该节点由子节点构成
///</summary>
///<paramname="HTChilds"></param>
///<paramname="ParentName"></param>
///<returns></returns>
public boolAddNodeByChild(HashtableHTChilds, stringParentName)
{
try
{

XmlNodeParent=xmlLog.CreateElement(ParentName);
XmlNodeChild;
IDictionaryEnumeratormyEnumerator=HTChilds.GetEnumerator();

while(myEnumerator.MoveNext())
{
Child=xmlLog.CreateElement(myEnumerator.Key.ToString());
Child.InnerText=myEnumerator.Value.ToString();
Parent.AppendChild(Child);
xmlLog.DocumentElement.AppendChild(Parent);

}
xmlLog.Save(context.Server.MapPath(xmlPath));
return true;
}
catch
{
return false;

}


}
///<summary>
///增加一个节点该节点由属性构成
///</summary>
///<paramname="htAttributes"></param>
///<paramname="NodeName"></param>
///<returns></returns>
public boolAddNodeByAttribute(HashtablehtAttributes, stringNodeName)
{
try
{
XmlNodeAddNode=xmlLog.CreateElement(NodeName);
IDictionaryEnumeratormyEnumerator=htAttributes.GetEnumerator();
XmlAttributeatr;
while(myEnumerator.MoveNext())
{
atr=xmlLog.CreateAttribute(myEnumerator.Key.ToString());
atr.InnerText=myEnumerator.Value.ToString();
AddNode.Attributes.Append(atr);
xmlLog.DocumentElement.AppendChild(AddNode);

}
xmlLog.Save(context.Server.MapPath(xmlPath));
return true;
}
catch
{
return false;

}

}
///<summary>
///或得指定查询节点得子节点数目
///</summary>
///<paramname="QueryPath"></param>
///<returns></returns>
public intChildCount( stringQueryPath)
{
try
{
XmlNodeResultNodes=xmlLog.SelectSingleNode(QueryPath);
returnResultNodes.ChildNodes.Count;

}
catch
{
return-1;

}

}
///<summary>
///删除指定路径的节点
///</summary>
///<paramname="QueryPath"></param>
///<returns></returns>
public boolDelelteNode( stringQueryPath)
{
try
{
XmlNodeListResultNodes=xmlLog.SelectNodes(QueryPath);
for( inti=0;i<ResultNodes.Count;i++)
{
XmlNodeParentNode=ResultNodes.ParentNode;
ParentNode.RemoveChild(ResultNodes);

}
xmlLog.Save(context.Server.MapPath(xmlPath));
return true;

}
catch
{
return false;
}

}
///<summary>
///查询节点
///</summary>
///<paramname="QueryPath"></param>
///<returns></returns>
publicXmlNodeListQueryNode( stringQueryPath)
{
try
{
XmlNodeListResultNodes=xmlLog.SelectNodes(QueryPath);
returnResultNodes;
}
catch
{
return null;
}


}
}
}