XML Chapter III: Editing XML file records
The easiest way to use C # to edit an XML file is, of course, to use a dataset
We continue to use the XML file in the previous article, as follows: <users> <xs:schema id= "users" xmlns= "xmlns:xs=" Http://www.w3.org/2001/XMLSchema "xmlns:msdata=" urn: Schemas-microsoft-com:xml-msdata "> <xs:element name=" Users msdata:isdataset= "true" msdata:locale= "Zh-CN" > <xs:complexType> <xs:choice maxoccurs= "unbounded" > <xs:element name= "User" > <xs:complexType> <xs:sequence> <xs:element name= "UserName" type= "xs:st Ring "minoccurs=" 0 "msdata:ordinal=" 0 "/> <xs:element name=" Userpass "type=" xs:string "minoccurs=" 0 " msdata:ordinal= "1"/> </xs:sequence> <xs:attribute name= "id" type= "xs:string"/> </xs:complexType> </xs:element> </xs:choice> </xs:complexType> </xs:element> </xs:schema> <user id= "1" > <userName>outrace</userName> <USERPASS&G T;mypass</userpass> </user> ≪user id= "2" > <userName>trace</userName> <userPass>mypass</userPass> </user> &l T;user id= "3" > <username>new user</username> <userpass>new passwd</userpass> </USER&G T;</users>
Then, we create a new XML file that reads as follows: <% @ Import namespace= "System.IO"%><% @ Import namespace= "System.Xml"%><% @ import namespace= "System.Dat" A "%><script language=" C # runat= "Server" >public void Page_Load (Object Src,eventargs e) {/** copyrights: Copyright by SEM IT department* Edition: Version 0.0.1* file: editxml.aspx* Purpose: Edit XML file (modify, delete line) * Author: Ouyang Yun @2005-4-9* Email: Out race@soueast-motor.com* Modification: * * String filename;filename = "Users_2.xml";D ataset myds = new DataSet (); Try{filestream F In; fin = new FileStream (Server.MapPath ("./files/" +filename), FileMode.Open, FileAccess.Read, fileshare.readwrite); Myds.readxml (Fin), fin. Close ();} catch (Exception ex) {Response.Write (ex. message);} Xmlolddata.datasource = Myds.tables[0] before binding modification. Defaultview;olddata.databind (); When the DS is added to the new line DataRow newrow = Myds.tables[0]. NewRow (); newrow["id"] = "n"; newrow["userName" = "test user"; newrow["userpass"] = "Test passwd"; Myds.tables[0]. Rows.Add (NewRow); Binding adds a record to the data Newdata.datasource = Myds.tables[0]. DefaulTview; Newdata.databind (); Filter datarow[] Editrow = myds.tables[0]. Select ("id = ' 44 '"); for (int i=0;i<editrow.length;i++) {editrow[i]["userName"] = "changed user"; editrow[i]["Userpass"] = "changed passwd";} Data Editdata.datasource = Myds.tables[0] After binding modification of records. DefaultView; Editdata.databind (); for (int i=0;i<editrow.length;i++) {editrow[i]. Delete (); Remove the data by deleting}//binding Data Deledata.datasource = Myds.tables[0] After deleting the record. Defaultview;deledata.databind (); Writes the myds changes to the Xmltry{myds.writexml (Server.MapPath ("./files/" +filename), Xmlwritemode.writeschema); catch (Exception ex) {Response.Write (ex. message);} Myds.dispose ();} </script><ptml><pead> <title> Edit Data </title></pead><body> <form runat= " Server "> <table width=" 100% "> <tr> <td> Original data </td> <td> New line </td> <td> Modify rows </td> <td> Delete lines </td> </tr> <tr> <td valign= "Top" ><asp:datagrid id= "Oldda Ta "runat= "Server"/></td> <td valign= "Top" ><asp:datagrid id= "NewData" runat= "Server"/></td> &L T;TD valign= "Top" ><asp:datagrid id= "EditData" runat= "Server"/></td> <td the "top" valign= Atagrid id= "Deledata" runat= "Server"/></td> </tr> </table> </form></body></ptml >After you run this file, you can very intuitive see the operation effect, because we are the last to save, so the content of the XML file has not changed
