读写XML文件

开发工具VS2010

新建test.xml文件，将xml文件存储目录目录下的调试目录，即与应用程序目录目录下

XML文件样式

<?xml version="1.0" encoding="utf-8"?>
<main>
  <user>admin</user>
  <psw>456</psw>
</main>

读取

 XmlDocument xml = new XmlDocument();
            xml.Load(Application.StartupPath+"//"+"test.xml");//加载xml文件
            XmlNode xn = xml.DocumentElement;
            tb_user.Text = xn["user"].InnerText;
            tb_psw.Text = xn["psw"].InnerText;
            label1.Text = xn["user"].InnerText +" "+ xn["psw"].InnerText;

写入

 XmlDocument xml = new XmlDocument();
            xml.Load(Application.StartupPath + "//" + "test.xml");//加载xml文件
            XmlNode xn = xml.DocumentElement;
            xn["user"].InnerText = tb_user.Text;
            xn["psw"].InnerText = tb_psw.Text;
            xml.Save(Application.StartupPath + "//" + "test.xml");//保存xml文件
            label1.Text = xn["user"].InnerText + " " + xn["psw"].InnerText;

完整代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Xml;

namespace RwXml
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btn_r_Click(object sender, EventArgs e)
        {
            XmlDocument xml = new XmlDocument();
            xml.Load(Application.StartupPath+"//"+"test.xml");//加载xml文件
            XmlNode xn = xml.DocumentElement;
            tb_user.Text = xn["user"].InnerText;
            tb_psw.Text = xn["psw"].InnerText;
            label1.Text = xn["user"].InnerText +" "+ xn["psw"].InnerText;
        }

        private void btn_w_Click(object sender, EventArgs e)
        {
            XmlDocument xml = new XmlDocument();
            xml.Load(Application.StartupPath + "//" + "test.xml");//加载xml文件
            XmlNode xn = xml.DocumentElement;
            xn["user"].InnerText = tb_user.Text;
            xn["psw"].InnerText = tb_psw.Text;
            xml.Save(Application.StartupPath + "//" + "test.xml");//保存xml文件
            label1.Text = xn["user"].InnerText + " " + xn["psw"].InnerText;
        }
    }
}

注：C#对xml文件进行操作，需要引用System.Xml