[LINQ] 建立 XML 檔案

學習 LINQ to XML 筆記，該篇是紀錄如何利用 XDocument 和 XElement 來建立 XML 檔案

Employee Class

namespace Helper
{
    public class Employee
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public bool Gender { get; set; }
        public int Salary { get; set; }
    }
}

DataHelper Class

namespace Helper
{
    public static class DataHelper
    {
        public static string XMLPath = @"D:\Temp\XMLDemo.xml";

        public static List<Employee> GetEmployees()
        {
            return new List<Employee>
            {
                new Employee {ID = 1, Name = "張三", Gender = false, Salary = 50000},
                new Employee {ID = 2, Name = "李四", Gender = true,  Salary = 45000},
                new Employee {ID = 3, Name = "王五", Gender = false, Salary = 65000},
                new Employee {ID = 4, Name = "丁六", Gender = true,  Salary = 28000}
            };
        }

        public static void XMLFileExist()
        {
            if (File.Exists(XMLPath) == false)
            {
                throw new FileNotFoundException(XMLPath);
            }
        }
    }
}

主程式

using Helper;
using System.Xml.Linq;

namespace _01_CreateXML
{
    class Program
    {
        static void Main(string[] args)
        {
            CreateXml_Simple();
            // CreateXML_Source();
        }

        private static void CreateXml_Simple()
        {
            XDocument xDoc = new XDocument(
                new XDeclaration("1.0", "utf-8", "yes"),
                new XComment("Linq2XML"),
                new XElement("Employees",
                    new XElement("Employee", new XAttribute("ID", 1),
                        new XElement("Name", "張三"),
                        new XElement("Gender", false),
                        new XElement("Salary", 50000)),
                    new XElement("Employee", new XAttribute("ID", 2),
                        new XElement("Name", "李四"),
                        new XElement("Gender", true),
                        new XElement("Salary", 45000)),
                    new XElement("Employee", new XAttribute("ID", 3),
                        new XElement("Name", "王五"),
                        new XElement("Gender", true),
                        new XElement("Salary", 65000)),
                    new XElement("Employee", new XAttribute("ID", 4),
                        new XElement("Name", "丁六"),
                        new XElement("Gender", true),
                        new XElement("Salary", 28000))));

				 // 會格式化 XML 
            xDoc.Save(DataHelper.XMLPath);
        }

        private static void CreateXML_Source()
        {
            List<Employee> EmployeeList = DataHelper.GetEmployees();

            XDocument xDoc = new XDocument
            (
                new XDeclaration("1.0", "utf-8", "yes"),
                new XComment("Linq2XML"),            
                new XElement
                (
                    "Employees",
                    EmployeeList.Select(s =>
                           new XElement("Employee", new XAttribute("ID", s.ID),
                                new XElement("Name", s.Name),
                                new XElement("Gender", s.Gender),
                                new XElement("Salary", s.Salary)))
                )
            );

            // SaveOptions.DisableFormatting 不格式化 XML，直接一行輸出
            xDoc.Save(DataHelper.XMLPath , SaveOptions.DisableFormatting);
        }
    }
}

參考資料
• 在 C# 中建立 XML 樹狀 (LINQ to XML)
• XDocument.Save 方法 (String, SaveOptions)
• 序列化時保留空白字元
  
• SaveOptions 列舉