C#实体类与XML相互转换

1、实体类与XML相互转换

将实体类转换成XML需要使用XmlSerializer类的Serialize方法，将实体类序列化。

把XML转换成相应的实体类，需要使用到XmlSerializer类的Deserialize方法，将XML进行反序列化。

创建XML序列化公共处理类（XmlSerializeHelper.cs）

using System;
using System.IO;
using System.Xml.Serialization;

/// <summary>
/// XML序列化公共处理类
/// </summary>
public static class XmlSerializeHelper
{
    /// <summary>
    /// 将实体对象转换成XML
    /// </summary>
    /// <typeparam name="T">实体类型</typeparam>
    /// <param name="obj">实体对象</param>
    public static string XmlSerialize<T>(T obj)
    {
        try
        {
            using (StringWriter sw = new StringWriter())
            {
                Type t = obj.GetType();
                XmlSerializer serializer = new XmlSerializer(obj.GetType());
                serializer.Serialize(sw, obj);
                sw.Close();
                return sw.ToString();
            }
        }
        catch (Exception ex)
        {
            throw new Exception("将实体对象转换成XML异常", ex);
        }
    }

    /// <summary>
    /// 将XML转换成实体对象
    /// </summary>
    /// <typeparam name="T">实体类型</typeparam>
    /// <param name="strXML">XML</param>
    public static T DESerializer<T>(string strXML) where T : class
    {
        try
        {
            using (StringReader sr = new StringReader(strXML))
            {
                XmlSerializer serializer = new XmlSerializer(typeof(T));
                return serializer.Deserialize(sr) as T;
            }
        }
        catch (Exception ex)
        {
            throw new Exception("将XML转换成实体对象异常", ex);
        }
    }
}           

创建用户信息类，用于示例使用。

/// <summary>
/// 用户信息类
/// </summary>
public class UserInfo
{
    /// <summary>
    /// 编号
    /// </summary>
    public int ID { get; set; }

    /// <summary>
    /// 名称
    /// </summary>
    public string Name { get; set; }

    /// <summary>
    /// 创建时间
    /// </summary>
    public DateTime? CreateTime { get; set; }
}           

1.1 示例1：将List与XML相互转换

/// <summary>
/// 将List与XML相互转换
/// </summary>
public static void ListToXmlTest()
{
    //获取用户列表
    List<UserInfo> userList = GetUserList();

    //将实体对象转换成XML
    string xmlResult = XmlSerializeHelper.XmlSerialize(userList);

    //将XML转换成实体对象
    List<UserInfo> deResult = XmlSerializeHelper.DESerializer<List<UserInfo>>(xmlResult);
}

/// <summary>
/// 获取用户信息列表
/// </summary>
public static List<UserInfo> GetUserList()
{
    List<UserInfo> userList = new List<UserInfo>();
    userList.Add(new UserInfo() { ID = 1, Name = "张三", CreateTime = DateTime.Now });
    userList.Add(new UserInfo() { ID = 2, Name = "李四", CreateTime = DateTime.Now });
    userList.Add(new UserInfo() { ID = 2, Name = "王五" });
    return userList;
}           

XML结果：

<?xml version="1.0" encoding="utf-16"?>
<ArrayOfUserInfo xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <UserInfo>
    <ID>1</ID>
    <Name>张三</Name>
    <CreateTime>2018-10-04T15:59:53.7761027+08:00</CreateTime>
  </UserInfo>
  <UserInfo>
    <ID>2</ID>
    <Name>李四</Name>
    <CreateTime>2018-10-04T15:59:54.9571044+08:00</CreateTime>
  </UserInfo>
  <UserInfo>
    <ID>2</ID>
    <Name>王五</Name>
    <CreateTime xsi:nil="true" />
  </UserInfo>
</ArrayOfUserInfo>           

1.2 示例2：将DataTable与XML相互转换

/// <summary>
/// 将DataTable与XML相互转换
/// </summary>
public static void DataTableToXmlTest()
{
    //创建DataTable对象
    DataTable dt = CreateDataTable();

    //将DataTable转换成XML
    string xmlResult = XmlSerializeHelper.XmlSerialize(dt);

    //将XML转换成DataTable
    DataTable deResult = XmlSerializeHelper.DESerializer<DataTable>(xmlResult);
}

/// <summary>
/// 创建DataTable对象
/// </summary>
public static DataTable CreateDataTable()
{
    //创建DataTable
    DataTable dt = new DataTable("NewDt");

    //创建自增长的ID列
    DataColumn dc = dt.Columns.Add("ID", Type.GetType("System.Int32"));
    dt.Columns.Add(new DataColumn("Name", Type.GetType("System.String")));
    dt.Columns.Add(new DataColumn("CreateTime", Type.GetType("System.DateTime")));

    //创建数据
    DataRow dr = dt.NewRow();
    dr["ID"] = 1;
    dr["Name"] = "张三";
    dr["CreateTime"] = DateTime.Now;
    dt.Rows.Add(dr);

    dr = dt.NewRow();
    dr["ID"] = 2;
    dr["Name"] = "李四";
    dr["CreateTime"] = DateTime.Now;
    dt.Rows.Add(dr);

    dr = dt.NewRow();
    dr["ID"] = 3;
    dr["Name"] = "王五";
    dr["CreateTime"] = DateTime.Now;
    dt.Rows.Add(dr);

    return dt;
}           

XML结果：

<?xml version="1.0" encoding="utf-16"?>
<DataTable>
  <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
    <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="NewDt" msdata:UseCurrentLocale="true">
      <xs:complexType>
        <xs:choice minOccurs="0" maxOccurs="unbounded">
          <xs:element name="NewDt">
            <xs:complexType>
              <xs:sequence>
                <xs:element name="ID" type="xs:int" minOccurs="0" />
                <xs:element name="Name" type="xs:string" minOccurs="0" />
                <xs:element name="CreateTime" type="xs:dateTime" minOccurs="0" />
              </xs:sequence>
            </xs:complexType>
          </xs:element>
        </xs:choice>
      </xs:complexType>
    </xs:element>
  </xs:schema>
  <diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1">
    <DocumentElement>
      <NewDt diffgr:id="NewDt1" msdata:rowOrder="0" diffgr:hasChanges="inserted">
        <ID>1</ID>
        <Name>张三</Name>
        <CreateTime>2018-10-04T16:06:10.8004082+08:00</CreateTime>
      </NewDt>
      <NewDt diffgr:id="NewDt2" msdata:rowOrder="1" diffgr:hasChanges="inserted">
        <ID>2</ID>
        <Name>李四</Name>
        <CreateTime>2018-10-04T16:06:10.8004082+08:00</CreateTime>
      </NewDt>
      <NewDt diffgr:id="NewDt3" msdata:rowOrder="2" diffgr:hasChanges="inserted">
        <ID>3</ID>
        <Name>王五</Name>
        <CreateTime>2018-10-04T16:06:10.8004082+08:00</CreateTime>
      </NewDt>
    </DocumentElement>
  </diffgr:diffgram>
</DataTable>           

2、序列化常用Attribute讲解说明

[XmlRootAttribute("MyCity", Namespace="abc.abc", IsNullable=false)]     // 当该类为Xml根节点时，以此为根节点名称。

public class City

[XmlAttribute("AreaName")]    // 表现为Xml节点属性。<... AreaName="..."/>

public string Name

[XmlElementAttribute("AreaId", IsNullable = false)]    // 表现为Xml节点。<AreaId>...</AreaId>

public string Id

[XmlArrayAttribute("Areas")]    // 表现为Xml层次结构，根为Areas，其所属的每个该集合节点元素名为类名。<Areas><Area ... /><Area ... /></Areas>

public Area[] Areas

[XmlElementAttribute("Area", IsNullable = false)]    // 表现为水平结构的Xml节点。<Area ... /><Area ... />...

public Area[] Areas

[XmlIgnoreAttribute]    // 忽略该元素的序列化。

把这些属性与model类的相关属性，配合使用，就可以自由设置相关XML的具体格式了。

综合示例：将班级信息序列化成XML

示例要求：

（1）每个XML节点以“My”开头。

（2）班级ID和学生ID字段以XML节点属性表现，其它字段以XML节点的形式表现。

（3）由于学生的邮箱涉及敏感信息，所以不参与序列化。

2.1 创建班级信息类（ClassInfo.cs）

using System.Collections.Generic;
using System.Xml.Serialization;

/// <summary>
/// 班级信息类
/// </summary>
[XmlRootAttribute("MyClassInfo", Namespace = "ABC_123", IsNullable = false)] 
public class ClassInfo
{
    /// <summary>
    /// 班级ID
    /// </summary>
    [XmlAttribute("MyClassID")]
    public int ClassID { get; set; }

    /// <summary>
    /// 班级名称
    /// </summary>
    [XmlElementAttribute("MyClassName", IsNullable = false)] 
    public string ClassName { get; set; }

    /// <summary>
    /// 班长人
    /// </summary>
    [XmlElementAttribute("MyTeacher", IsNullable = false)] 
    public string Teacher { get; set; }

    /// <summary>
    /// 学生列表
    /// </summary>
    [XmlArrayAttribute("MyStudents")]  
    public List<Student> StudentList { get; set; }
}           

2.2 创建学生信息类（Student.cs）

using System.Xml.Serialization;

/// <summary>
/// 学生信息类
/// </summary>
[XmlRootAttribute("MyStudent", IsNullable = false)] 
public class Student
{
    /// <summary>
    /// 学生ID
    /// </summary>
    [XmlAttribute("MyStuID")]
    public int StuID { get; set; }

    /// <summary>
    /// 学生名称
    /// </summary>
    [XmlElementAttribute("MyStuName", IsNullable = false)] 
    public string StuName { get; set; }

    /// <summary>
    /// 性别
    /// </summary>
    [XmlElementAttribute("MySex", IsNullable = false)] 
    public string Sex { get; set; }

    /// <summary>
    /// 邮箱
    /// </summary>
    [XmlIgnoreAttribute] 
    public string Email { get; set; }
}           

2.3 将班级信息转换成XML

/// <summary>
/// 将班级信息转换成XML
/// </summary>
public static void ClassInfoToXml()
{
    //获取班级信息
    ClassInfo classInfo = GetClassInfo();

    //将班级信息转换成XML
    string classXml = XmlSerializeHelper.XmlSerialize(classInfo);
}

/// <summary>
/// 获取班级信息
/// </summary>
public static ClassInfo GetClassInfo()
{
    //创建班级信息
    ClassInfo classInfo = new ClassInfo();
    classInfo.ClassID = 1;
    classInfo.ClassName = "高一（5）班";
    classInfo.Teacher = "李老师";

    //创建学生列表
    List<Student> studentList = new List<Student>();
    studentList.Add(new Student() { StuID = 1, StuName = "张三", Sex = "男", Email = "[email protected]" });
    studentList.Add(new Student() { StuID = 2, StuName = "李四", Sex = "女", Email = "[email protected]" });
    studentList.Add(new Student() { StuID = 3, StuName = "王五", Sex = "男", Email = "[email protected]" });
    classInfo.StudentList = studentList;

    return classInfo;
}           

XML结果：

<?xml version="1.0" encoding="utf-16"?>
<MyClassInfo xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" MyClassID="1" xmlns="ABC_123">
  <MyClassName>高一（5）班</MyClassName>
  <MyTeacher>李老师</MyTeacher>
  <MyStudents>
    <Student MyStuID="1">
      <MyStuName>张三</MyStuName>
      <MySex>男</MySex>
    </Student>
    <Student MyStuID="2">
      <MyStuName>李四</MyStuName>
      <MySex>女</MySex>
    </Student>
    <Student MyStuID="3">
      <MyStuName>王五</MyStuName>
      <MySex>男</MySex>
    </Student>
  </MyStudents>
</MyClassInfo>