Question

我创建了一个类Employee，如下所示

class Employee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Gender { get; set; }
    public int Salary { get; set; }

    public static Employee[] GetAllEmployee()
    {
        Employee[] Emp = new Employee[5];

        Emp[0] = new Employee { Id = 101, Name = "Mery", Gender = "Female", Salary = 10000 };
        Emp[1] = new Employee { Id = 102, Name = "Lucy", Gender = "Female", Salary = 12000 };
        Emp[2] = new Employee { Id = 103, Name = "Jeny", Gender = "Female", Salary = 15000 };
        Emp[3] = new Employee { Id = 104, Name = "Lilly", Gender = "Female",Salary = 10000 };
        Emp[4] = new Employee { Id = 105, Name = "Sony", Gender = "Female", Salary = 17000 };

        return Emp;
    }

现在我想检索薪水超过10000的员工的姓名。所以我使用这个代码，但它给出了错误，需要进行哪些修正？

IEnumerable<string> Names = from Emps in XDocument.Load(@"path\Data.xml")
                                                           .Descendants("Employee")
                            where (int)Emps.Element("Salary") > 10000

                            select Emps.Element("Name").Value;

foreach(string name in Names)
{
    Console.WriteLine(name);
    Console.ReadLine();
}

Answer 1

以下代码有效。 xml文档在根级别不能有数组。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.Xml.Serialization;
using System.IO;

namespace ConsoleApplication1
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            Company company = new Company();
            XmlSerializer serializer = new XmlSerializer(typeof(Company));

            StreamWriter writer = new StreamWriter(FILENAME);
            serializer.Serialize(writer, company);
            writer.Flush();
            writer.Close();
            writer.Dispose();

            IEnumerable<string> Names = from Emps in XDocument.Load(FILENAME)
                                                           .Descendants("Employee")
                                        where (int)Emps.Element("Salary") > 10000

                                        select Emps.Element("Name").Value;

            foreach (string name in Names)
            {
                Console.WriteLine(name);
            }
            Console.ReadLine();
        }
    }
    public class Company
    {
        [XmlElement("Employee")]
        public Employee[] employees = Employee.GetAllEmployee();
    }
    public class Employee
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Gender { get; set; }
        public int Salary { get; set; }

        public static Employee[] GetAllEmployee()
        {
            Employee[] Emp = new Employee[5];

            Emp[0] = new Employee { Id = 101, Name = "Mery", Gender = "Female", Salary = 10000 };
            Emp[1] = new Employee { Id = 102, Name = "Lucy", Gender = "Female", Salary = 12000 };
            Emp[2] = new Employee { Id = 103, Name = "Jeny", Gender = "Female", Salary = 15000 };
            Emp[3] = new Employee { Id = 104, Name = "Lilly", Gender = "Female", Salary = 10000 };
            Emp[4] = new Employee { Id = 105, Name = "Sony", Gender = "Female", Salary = 17000 };

            return Emp;
        }
    }
}

System.Xml.Linq.dll中发生未处理的“System.ArgumentNullException”类型的异常附加信息：值不能为null

1 个答案: