C# 读写XML文件实例代码

C#史上最简单读写xml文件方式，创建控制台应用程序赋值代码，就可以运行，需要改动，请自行调整

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;

namespace ConsoleApp1
{
 class Program
 {
   public const String xmlPath = "info.xml";

static void Main(string[] args)
   {

IDictionary<String, List<String>> infos = new Dictionary<String, List<String>>();

infos.Add("Evan", new List<string>() { "123", "456" });

SaveXML(infos);

ReadXML();
     Console.ReadKey();
   }

public static void SaveXML(IDictionary<String, List<String>> infos)
   {
     if (infos == null || infos.Count == 0)
     {
       return;
     }

XmlDocument xmlDoc = new XmlDocument();

XmlDeclaration dec = xmlDoc.CreateXmlDeclaration("1.0", "utf-8", null);

xmlDoc.AppendChild(dec);

XmlElement _infos = xmlDoc.CreateElement("infos");

foreach (KeyValuePair<String, List<String>> item in infos)
     {
       XmlElement info = xmlDoc.CreateElement("info");

XmlElement name = xmlDoc.CreateElement("file1");
       name.InnerText = item.Key;

info.AppendChild(name);

XmlNode filelist = xmlDoc.CreateElement("filelist");

info.AppendChild(filelist);

foreach (String number in item.Value)
       {
         XmlElement filed = xmlDoc.CreateElement("filed");
         filed.InnerText = number;

filelist.AppendChild(filed);
       }

_infos.AppendChild(info);
     }

xmlDoc.AppendChild(_infos);

xmlDoc.Save(xmlPath);
   }

public static IDictionary<String, List<String>> ReadXML()
   {
     IDictionary<String, List<String>> infos = new Dictionary<String, List<String>>();

if (File.Exists(xmlPath))
     {
       XmlDocument xmlDoc = new XmlDocument();

xmlDoc.Load(xmlPath);

XmlNode xn = xmlDoc.SelectSingleNode("infos");

XmlNodeList xnl = xn.ChildNodes;

foreach (XmlNode xnf in xnl)
       {
         XmlElement xe = (XmlElement)xnf;

XmlNode nameNode = xe.SelectSingleNode("file1");

string name = nameNode.InnerText;
         Console.WriteLine(name);
         XmlNode filelist = xe.SelectSingleNode("filelist");

List<String> list = new List<string>();

foreach (XmlNode item in filelist.ChildNodes)
         {
           list.Add(item.InnerText);
         }

infos.Add(name, list);
       }
     }

return infos;
   }
 }
}

内容扩展：

实例代码

dim domxmldocument as system.xml.xmldocument
 dim tmppath as string = apptempfilepath
 dim xmlfile as string = tmppath + "＼testxml.xml"
'窗体加载事件
 private sub testxml_load(byval sender as system.object, byval e as system.eventargs) handles mybase.load
 '读xml过程测试通过
 dim domxmldocument as system.xml.xmldocument
 dim tmppath as string = apptempfilepath
 dim xmlfile as string = tmppath + "＼testxml.xml"
 dim reader as system.xml.xmlreader = nothing
 try
 reader = new xml.xmltextreader(xmlfile)
 'reader.
 while reader.read
 me.lboxxml.items.add(reader.name + reader.value)
 end while
 catch ex as exception
 msgbox(ex.message)
 finally
 if not (reader is nothing) then
 reader.close()
 end if
 end try
 end sub
 '载入xml事件
 private sub btnxmlload_click(byval sender as system.object, byval e as system.eventargs) handles btnxmlload.click
 'me.lboxxml.items.clear()
 ''读xml过程测试通过
 'dim reader as system.xml.xmlreader = nothing
 'try
 ' reader = new xml.xmltextreader(xmlfile)
 ' while reader.read
 ' me.lboxxml.items.add(reader.name + ":" + reader.value)
 ' end while
 'catch ex as exception
 ' msgbox(ex.message)
 'finally
 ' if not (reader is nothing) then
 ' reader.close()
 ' end if
 'end try
 dim ds as new dataset
 try
 '如果直接使用ds做datasource则不会展开datagrid，用dv则能直接显示正确。
 ds.readxml(xmlfile)
 dim tb as datatable
 dim dv as dataview
 tb = ds.tables(0)
 dv = new dataview(tb)
 datagrid1.datasource = dv
 'datagrid1.datamember = "testxmlmember"
 'datagrid1.datamember = "employeefname"
 'dim dxd as new xmldatadocument
 catch ex as exception
 msgbox(ex.message.tostring)
 end try
 end sub
 '保存新建xml内容事件
 private sub btnsavenew_click(byval sender as system.object, byval e as system.eventargs) handles btnsavenew.click
 dim mytw as new xmltextwriter(tmppath + "＼testxmlwrite.xml", nothing)
 mytw.writestartdocument()
 mytw.formatting = formatting.indented
 mytw.writestartelement("team")
 mytw.writestartelement("player")
 mytw.writeattributestring("name", "george zip")
 mytw.writeattributestring("position", "qb")
 mytw.writeelementstring("nickname", "zippy")
 mytw.writeelementstring("jerseynumber", xmlconvert.tostring(7))
 mytw.writeendelement()
 mytw.writeendelement()
 mytw.writeenddocument()
 mytw.close()
 end sub

文件很大的情况下，可以考虑手动实现数据更新适配器，比如手动实现一个xml节点搜索/更新，这样就不用重写整个xml。
如果程序的i/o不是主要问题，还是用实体类整个的写入更新吧，毕竟数据的完整性是第一位的。
如是文章类的，对该目录建一个xml索引文件来存放文章的编号，url等，用xml的attribute作为标记不同字段，内容页面可以用另外的html或xml页面存放，用linq to xml操作数据，效率不是很差，个人观点。当搜索时候只要查询指定文件名xml或文件类型就可以了。

来源：https://www.cnblogs.com/OmySql/p/12405569.html