C#读写xml文件

<? xml version="1.0" encoding="gb2312" ?>
< bookstore >   
      < book  genre ="fantasy"  ISBN ="2-3631-4" >     
           < title > Oberon's Legacy </ title >     
           < author > Corets, Eva </ author >     
           < price > 5.95 </ price >   
      </ book >
</ bookstore >

            XmlDocument xmlDoc  =   new  XmlDocument();
            xmlDoc.Load( " da.xml " );
            XmlNode root  =  xmlDoc.SelectSingleNode( " bookstore " ); // 查找<bookstore>
            XmlElement xe1  =  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
            XmlElement xesub1  =  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
            XmlElement xesub2  =  xmlDoc.CreateElement( " author " );
            xesub2.InnerText  =   " 候捷 " ;
            xe1.AppendChild(xesub2);
            XmlElement xesub3  =  xmlDoc.CreateElement( " price " );
            xesub3.InnerText  =   " 58.3 " ;
            xe1.AppendChild(xesub3);
            root.AppendChild(xe1); // 添加到<bookstore>节点中
            xmlDoc.Save( " da.xml " );

<? xml version="1.0" encoding="gb2312" ?>
< bookstore >
   < book  genre ="fantasy"  ISBN ="2-3631-4" >
     < title > Oberon's Legacy </ title >
     < author > Corets, Eva </ author >
     < price > 5.95 </ price >
   </ book >
   < book  genre ="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 >

XmlNodeList nodeList = xmlDoc.SelectSingleNode( " bookstore " ).ChildNodes;
// 获取bookstore节点的所有子节点
foreach (XmlNode xn  in  nodeList) // 遍历所有子节点
{
    XmlElement xe = (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”
        XmlNodeList nls = xe.ChildNodes; // 继续获取xe子节点的所有子节点
          foreach (XmlNode xn1  in  nls) // 遍历
         {
              XmlElement xe2 = (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。

<? xml version="1.0" encoding="utf-8"  ?>
< google >
   < googleColorBorder > f6fbff </ googleColorBorder >
   < googleColorBG > f6fbff </ googleColorBG >
   < googleColorLink > 666666 </ googleColorLink >
   < googleColorText > 046b7A </ googleColorText >
   < googleColorUrl > 008000 </ googleColorUrl >
</ google >

protected   void  Page_Load( object  sender, EventArgs e)
    {
        XmlTextReader xtr  =   new  XmlTextReader( " c:\\AdColor2.xml " );
         while  (xtr.Read()) {
             if  (xtr.NodeType  ==  XmlNodeType.Element  &&  xtr.LocalName  ==   " googleColorBorder " ) {
                Response.Write(xtr.ReadString()  +   " <br/> " );
            }

             if  (xtr.NodeType  ==  XmlNodeType.Element  &&  xtr.LocalName  ==   " googleColorBG " )
            {
                Response.Write(xtr.ReadString()  +   " <br/> " );
            }

             if  (xtr.NodeType  ==  XmlNodeType.Element  &&  xtr.LocalName  ==   " googleColorLink " )
            {
                Response.Write(xtr.ReadString()  +   " <br/> " );
            }

             if  (xtr.NodeType  ==  XmlNodeType.Element  &&  xtr.LocalName  ==   " googleColorText " )
            {
                Response.Write(xtr.ReadString()  +   " <br/> " );
            }

             if  (xtr.NodeType  ==  XmlNodeType.Element  &&  xtr.LocalName  ==   " googleColorUrl " )
            {
                Response.Write(xtr.ReadString()  +   " <br/> " );
            }

        }
    }