C# 利用System.Xml.Linq對XML文件進行處理

Namespace

• using System;
• using System.Linq;
• using System.Xml.Linq;

Building Model

using System;
using System.Xml.Linq;

namespace Melphi.XmlServices
{
    /// <summary>
    /// 用戶
    /// </summary>
    public class User
    {
        public string Name { get; set; }
        public string Authority { get; set; }
        public string key { get; set; }
    }

    /// <summary>
    /// 項目
    /// </summary>
    public class Project
    {
        public User User { get; set; }
        public string Name { get; set; }
        public string Frame { get; set; }
        public string Language { get; set; }
        public string Output { get; set; }
        public string CreateDate { get; set; }
    }
}

Create XML File

using System;
using System.Xml.Linq;

namespace Melphi.XmlServices
{
    public class XmlService
    {
        /// <summary>
        /// 創建XML文件
        /// </summary>
        /// <param name="path">創建文本路徑</param>
        public static void CreateXmlFile(string path)
        {
            XDocument xDocument = new XDocument();
            // 創建根節點
            XElement xRoot = new XElement("melproj");

            // 創建節點的子節點
            XElement xeUser = new XElement(
                new XElement("user",
                new XElement("name", "Melphily"),
                new XElement("authority", "0"),
                new XElement("key", "DFASC-FRPDS-OOPAD-MJHWD-PLODDE"))
                );

            // 創建節點的子節點和節點屬性
            XElement xeProject = new XElement(
                new XElement("project",
                new XAttribute("name", "Melphi.XmlServices"),
                new XAttribute("frame", ".NET Standard 2.0"),
                new XAttribute("language", "C#"),
                new XAttribute("output", ".dll"),
                new XElement("createdate", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")))
               );

            // 將節點添加到根節點上
            xRoot.Add(xeUser);
            xRoot.Add(xeProject);
            xDocument.Add(xRoot);
            // 保存XML文件
            xDocument.Save(System.IO.Path.Combine(path, @"melproj.xml"));
        }
    }
}

Read XML File

using System;
using System.Xml.Linq;

namespace Melphi.XmlServices
{
    public class XmlService
    {
          /// <summary>
        /// 獲取XML文件信息 
        /// </summary>
        /// <param name="path">路徑</param>
        /// <returns>返回 <see cref="Project" /> 類型的數據模型</returns>
        public static Project ReadXmlFile(string path)
        {
            Project result = new Project();

            // 加載XML文件
            XElement xElement = XElement.Load(System.IO.Path.Combine(path, @"melproj.xml"));

            result.User = new User();
            // 獲取某個節點的子節點
            foreach (var item in xElement.Element("user").Elements())
            {
                switch (item.Name.ToString())
                {
                    case "name":
                        result.User.Name = item.Value.ToString();
                        break;
                    case "authority":
                        result.User.Authority = item.Value.ToString();
                        break;
                    case "key":
                        result.User.key = item.Value.ToString();
                        break;
                    default:
                        break;
                }
            }

            // 獲取某個節點的子節點
            foreach (var item in xElement.Element("project").Elements())
            {
                switch (item.Name.ToString())
                {
                    case "createdate":
                        result.CreateDate = item.Value.ToString();
                        break;
                    default:
                        break;
                }
            }

            // 獲取某個節點的屬性
            foreach (var item in xElement.Element("project").Attributes())
            {
                switch (item.Name.ToString())
                {
                    case "name":
                        result.Name = item.Value.ToString();
                        break;
                    case "frame":
                        result.Frame = item.Value.ToString();
                        break;
                    case "language":
                        result.Language= item.Value.ToString();
                        break;
                    case "output":
                        result.Output= item.Value.ToString();
                        break;
                    default:
                        break;
                }
            }

            return result;
        }
    }
}

Modify XML File

using System;
using System.Xml.Linq;

namespace Melphi.XmlServices
{
    public class XmlService
    {
		/// <summary>
        /// 修改XML文件節點或者屬性的內容
        /// </summary>
        /// <param name="path">路徑</param>
        /// <param name="projectName">修改的值</param>
        public static void ModifyXMLFile(string path, string projectName)
        {
            XElement xe = XElement.Load(System.IO.Path.Combine(path, @"melproj.xml"));

            // 修改某個屬性屬性
            xe.Element("project").Attribute("name").SetValue(projectName);

            // 修改某個節點內容
            xe.Element("user").Element("name").SetValue("John");

            // 保存修改文件
            xe.Save(System.IO.Path.Combine(path, @"melproj.xml"));
        }
	}
}

Add A Node To XML File

using System;
using System.Xml.Linq;

namespace Melphi.XmlServices
{
    public class XmlService
    {
        /// <summary>
        /// 添加新節點到XML文件中
        /// </summary>
        /// <param name="path">路徑</param>
        public static void AddXmlNodeToFile(string path)
        {
            XElement xe = XElement.Load(System.IO.Path.Combine(path, @"melproj.xml"));

            // 添加的節點
            XElement adddingItem = new XElement(new XElement("content", new XElement("cs", "3"), new XElement("xaml", "2")));

            // 添加到根節點
            xe.Add(adddingItem);

            // 保存修改文件
            xe.Save(System.IO.Path.Combine(path, @"melproj.xml"));
        }
    }
}

Delete A Node From XML File

using System;
using System.Linq;
using System.Xml.Linq;

namespace Melphi.XmlServices
{
    public class XmlService
    {
        /// <summary>
        /// 刪除某個節點
        /// </summary>
        /// <param name="path">路徑</param>
        public static void DeleteANodeFromFile(string path)
        {
            XElement xe = XElement.Load(System.IO.Path.Combine(path, @"melproj.xml"));

            // 當 xaml = 2 時，刪除 content 節點所有內容
            var xElements = from ele in xe.Elements("content") where (string)ele.Element("xaml") == "2" select ele;

            // 如果存在以上條件的 content 節點
            if (xElements.Count() > 0)
            {
                // 刪除這個節點
                xElements.First().Remove();
            }
           
            // 保存修改文件
            xe.Save(System.IO.Path.Combine(path, @"melproj.xml"));
        }
    }
}

XML File View

<?xml version="1.0" encoding="utf-8"?>
<melproj>
  <user>
    <name>Melphily</name>
    <authority>0</authority>
    <key>DFASC-FRPDS-OOPAD-MJHWD-PLODDE</key>
  </user>
  <project name="Melphi.XmlServices" frame=".NET Standard 2.0" language="C#" output=".dll">
    <createdate>2020-01-11 16:20:31</createdate>
  </project>
</melproj>