xml文档的添加，删除，修改（二）

//增加新会员 0表成功，-1表已存在同名会员
public int UserAdd(string sID, string sPass, string sNickname, string sTel,
string sEmail, string sAddress){
XmlDocument doc = new XmlDocument();
XmlNode node;
XmlElement rootNode;
string sSelect;

doc.Load("c://InetPub//wwwroot//UserMan//userlist.xml");
rootNode = doc.DocumentElement;
sSelect = "descendant::user[id = '" + sID + "' ]";
node= rootNode.SelectSingleNode(sSelect);

if (node != null)
return -1; //已存在同名会员

XmlElement elem = doc.CreateElement( "user" ); //新建一个user元素
//注意标记后的空格
string sXml = "<id>" + sID + "</id> " + "<pass>" + sPass + "</pass> " +
"<nickname>" + sNickname + "</nickname> " + "<tel>" + sTel + "</tel> " + "<email>" + sEmail + "</email> " + "<address>" + sAddress + "</address> ";

elem.InnerXml = sXml; //设定该user元素的内容
rootNode.AppendChild( elem ); //将新加的user元素作为根结点的子结点

doc.Save( "c://InetPub//wwwroot//UserMan//userlist.xml" ); //存盘
return 0;
}
//删除会员 0表成功，-1表会员不存在 –2表密码错
public int UserDelete( string sID, string sPass){
XmlDocument doc = new XmlDocument();
XmlNode node, nodeDelete;
XmlElement rootNode;
string sSelect;
doc.Load("c://InetPub//wwwroot//UserMan//userlist.xml");
rootNode = doc.DocumentElement;
sSelect = "descendant::user[id = '" + sID + "' ]";
//nodeDelete指向准备删除的结点
nodeDelete = node = rootNode.SelectSingleNode(sSelect);
if (node == null)
return -1; //返回会员不存在错误

node = node.ChildNodes[1];

if ( node.InnerText != sPass )
return -2; //密码错
rootNode.RemoveChild( nodeDelete ); //删除该user结点
doc.Save( "c://InetPub//wwwroot//UserMan//userlist.xml" ); //存盘
return 0;
}