Ling To Xml 学习之 对xml增、删、改、查

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.Linq;
using System.Xml;

namespace lingtoxml
{
    public partial class Ling_student_xml : Form
    {
        string xmlPath = "StuInfo.xml";
        public Ling_student_xml()
        {
            InitializeComponent();
        }

        private void Ling_student_xml_Load(object sender, EventArgs e)
        {
            datagridBind();
        }
        public void datagridBind()
        {
            DataSet ds = new DataSet();
            ds.ReadXml(xmlPath);
            dataGridView1.DataSource = ds.Tables[0];
        }
        //添加信息到xml中去
        private void AddEnter_Click(object sender, EventArgs e)
        {
            //1、加载xml
           
            XElement xelment = XElement.Load(xmlPath);
            //2、实例化泛型接口
            IEnumerable<XElement> xelments = from xe in xelment.Elements("stu")
                                             select xe;

            //生成相应的数据
            string SID = Convert.ToInt32(xelments.Max(xe => xe.Attribute("ID").Value)+1).ToString("0000");
            XElement stu = new XElement("stu", new XAttribute("ID", SID),
                new XElement("Name",textBox1.Text),
                new XElement("Sex",textBox2.Text),
                new XElement("Age",textBox3.Text),
                new XElement("Grad",textBox4.Text)

            );
            xelment.Add(stu);//添加xml元素
            xelment.Save(xmlPath);//保存xml
            datagridBind();
        }
        // 根据选择的ID获得详细信息
        private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            string keys = dataGridView1.Rows[e.RowIndex].Cells[4].Value.ToString();//获取ID
            XElement xelment=XElement.Load(xmlPath);//加载xml
            //根据编号查找
            IEnumerable<XElement> xelments = from xe in xelment.Elements("stu")
                                             where xe.Attribute("ID").Value == keys
                                             select xe;
            foreach (XElement item in xelments)
            {
                textBox5.Text = item.Attribute("ID").Value.ToString();
                textBox1.Text = item.Element("Name").Value.ToString();
                textBox2.Text = item.Element("Sex").Value.ToString();
                textBox3.Text = item.Element("Age").Value.ToString();
                textBox4.Text = item.Element("Grad").Value.ToString();
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            XElement xelment = XElement.Load(xmlPath);
            if (textBox5.Text != "")
            {
                IEnumerable<XElement> xelments = from xe in xelment.Elements("stu")
                                                 select xe;
                if (xelments.Count() != 0)
                {
                    XElement newXE = xelments.First();
                    newXE.SetAttributeValue("ID", textBox5.Text);
                    newXE.ReplaceNodes(
                        new XElement("Name",textBox1.Text),
                        new XElement("Sex",textBox2.Text),
                        new XElement("Age",textBox3.Text),
                        new XElement("Grad",textBox4.Text)
                        );
                }
                xelment.Save(xmlPath);
            }
            datagridBind();
        }


    }
}