XML 增、删、改和查示例

1.已知有一个XML文件（bookstore.xml）如下：

<?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>

1、往<bookstore>节点中插入一个<book>节点：

XmlDocument xmlDoc=new XmlDocument(); xmlDoc.Load(\”bookstore.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(\”bookstore.xml\”);

//================ 结果为：

<?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>

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”。

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=\”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=\”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>

XmlNodeList xnl=xmlDoc.SelectSingleNode(\”bookstore\”).ChildNodes; foreach(XmlNode xn in xnl) { XmlElement xe=(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\”);

<?xml version=\”1.0\” encoding=\”gb2312\”?><bookstore> <book ISBN=\”2-3631-4\”> <title>Oberon\’s Legacy</title> <author>Corets, Eva</author> <price>5.95</price> </book> <book> </book></bookstore>

XmlNode xn=xmlDoc.SelectSingleNode(\”bookstore\”); XmlNodeList xnl=xn.ChildNodes; foreach(XmlNode xnf in xnl) { XmlElement xe=(XmlElement)xnf; Console.WriteLine(xe.GetAttribute(\”genre\”));//显示属性值 Console.WriteLine(xe.GetAttribute(\”ISBN\”)); XmlNodeList xnf1=xe.ChildNodes; foreach(XmlNode xn2 in xnf1) { Console.WriteLine(xn2.InnerText);//显示子节点点文本 } }

System;

System.Collections;

System.ComponentModel;

System.Data;

System.Drawing;

System.Web;

System.Web.SessionState;

System.Web.UI;

System.Web.UI.WebControls;

System.Web.UI.HtmlControls;

System.Xml;

System.Xml.XPath;

DsAndXML.OpXMLFile

{/**////<summary>///Main的摘要说明。///</summary>publicclassMain:System.Web.UI.Page{protectedSystem.Web.UI.WebControls.ButtonbtnQuery;protectedSystem.Web.UI.WebControls.ButtonbtnChange;protectedSystem.Web.UI.WebControls.ButtonbtnDelete;protectedSystem.Web.UI.WebControls.ButtonbtnAdd;protectedSystem.Web.UI.WebControls.DropDownListddlName;protectedSystem.Web.UI.WebControls.LabelLabel1;protectedSystem.Web.UI.WebControls.LabelLabel2;protectedSystem.Web.UI.WebControls.LabellbEmail;protectedSystem.Web.UI.WebControls.TextBoxtbNewMail;protectedSystem.Web.UI.WebControls.LabelLabel3;protectedSystem.Web.UI.WebControls.DataGriddgShow;privatevoidPage_Load(objectsender,System.EventArgse){//在此处放置用户代码以初始化页面if(!IsPostBack)Bind();}privatevoidBind(){DataSetds=newDataSet();ds.ReadXml(Server.MapPath(\”.\\\\db\\\\dbGuest.xml\”));dgShow.DataSource=ds.Tables[0].DefaultView;dgShow.DataBind();XmlDocumentdoc=newXmlDocument();doc.Load(Server.MapPath(\”.\\\\db\\\\dbGuest.xml\”));XmlNodeListelemList=doc.GetElementsByTagName(\”Name\”);ddlName.Items.Clear();for(inti=0;i<elemList.Count;i++)ddlName.Items.Add(elemList[i].InnerXml);}WebFormDesignergeneratedcode#regionWebFormDesignergeneratedcodeoverrideprotectedvoidOnInit(EventArgse){////CODEGEN：该调用是ASP.NETWeb窗体设计器所必需的。//InitializeComponent();base.OnInit(e);}/**////<summary>///设计器支持所需的方法-不要使用代码编辑器修改///此方法的内容。///</summary>privatevoidInitializeComponent(){this.btnQuery.Click+=newSystem.EventHandler(this.btnQuery_Click);this.btnChange.Click+=newSystem.EventHandler(this.btnChange_Click);this.btnDelete.Click+=newSystem.EventHandler(this.btnDelete_Click);this.btnAdd.Click+=newSystem.EventHandler(this.btnAdd_Click);this.Load+=newSystem.EventHandler(this.Page_Load);}#endregionprivatevoidbtnQuery_Click(objectsender,System.EventArgse){XmlDocumentdoc=newXmlDocument();doc.Load(Server.MapPath(\”.\\\\db\\\\dbGuest.xml\”));lbEmail.Text=doc.SelectSingleNode(\”//User[Name=\’\”+ddlName.SelectedItem.Text+\”\’]\”).ChildNodes.Item(2).InnerText;}privatevoidbtnChange_Click(objectsender,System.EventArgse){XmlDocumentxmlDoc=newXmlDocument();xmlDoc.Load(Server.MapPath(\”.\\\\db\\\\dbGuest.xml\”));XmlNodeListnodeList=xmlDoc.SelectSingleNode(\”dbGuest\”).ChildNodes;//获取dbGuest节点的所有子节点foreach(XmlNodexninnodeList)//遍历所有子节点{XmlElementxe=(XmlElement)xn;//将子节点类型转换为XmlElement类型XmlNodeListnode=xe.GetElementsByTagName(\”Name\”);if(node.Count>0){if(node[0].InnerText==ddlName.SelectedItem.Text){XmlNodeListnls=xe.ChildNodes;//继续获取xe子节点的所有子节点foreach(XmlNodexn1innls)//遍历{XmlElementxe2=(XmlElement)xn1;//转换类型if(xe2.Name==\”Email\”)//如果找到{xe2.InnerText=tbNewMail.Text;//则修改break;//找到退出来就可以了}}break;}}}xmlDoc.Save(Server.MapPath(\”.\\\\db\\\\dbGuest.xml\”));Bind();}privatevoidbtnDelete_Click(objectsender,System.EventArgse){XmlDocumentxmlDoc=newXmlDocument();xmlDoc.Load(Server.MapPath(\”.\\\\db\\\\dbGuest.xml\”));XmlNodeListxnl=xmlDoc.SelectSingleNode(\”dbGuest\”).ChildNodes;foreach(XmlNodexninxnl){XmlElementxe=(XmlElement)xn;XmlNodeListnode=xe.GetElementsByTagName(\”Name\”);if(node.Count>0){if(node[0].InnerText==ddlName.SelectedItem.Text)xe.RemoveAll();//删除该节点的全部内容break;}}xmlDoc.Save(Server.MapPath(\”.\\\\db\\\\dbGuest.xml\”));Bind();}privatevoidbtnAdd_Click(objectsender,System.EventArgse){XmlDocumentxmlDoc=newXmlDocument();xmlDoc.Load(Server.MapPath(\”.\\\\db\\\\dbGuest.xml\”));XmlNoderoot=xmlDoc.SelectSingleNode(\”dbGuest\”);//查找<dbGuest>XmlElementxe1=xmlDoc.CreateElement(\”User\”);//创建一个<User>节点XmlElementxesub1=xmlDoc.CreateElement(\”Name\”);xesub1.InnerText=\”Guset\”;//设置文本节点xe1.AppendChild(xesub1);//添加到<User>节点中XmlElementxesub2=xmlDoc.CreateElement(\”City\”);xesub2.InnerText=\”上海\”;xe1.AppendChild(xesub2);XmlElementxesub3=xmlDoc.CreateElement(\”Email\”);xesub3.InnerText=\”ss@22.net\”;xe1.AppendChild(xesub3);root.AppendChild(xe1);//添加到<dbGuest>节点中xmlDoc.Save(Server.MapPath(\”.\\\\db\\\\dbGuest.xml\”));Bind();}}}