net中序列化读写xml

参考http://www.cnblogs.com/fish-li/archive/2013/05/05/3061816.html

我们可以直接使用XmlTextReader、XmlDocument、XPath来取数XML中的数据， 也可以使用LINQ TO XML或者反序列化的方法从XML中读写数据，我各人比较喜欢序列化、反序列化方法。

1、默认情况下，不添加任何属性标签的对象属性都序列化为一个节点。如下一个Student对象序列化结果如下：

public class Student
    {
        public string Name { get; set; }//属性无任何修饰都序列化为Element

        public string Sex { get; set; }

        public int Age { get; set; }
    }
Student stu = new Student()
            {
                Name = "LiLei",
                Age = 25,
                Sex = "男"
            };
string xml= XmlHelper.XmlSerialize(stu, Encoding.UTF8);//序列化

序列化结果如下：

<?xml version="1.0" encoding="utf-8"?>
<Student xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Name>LiLei</Name>
  <Sex>男</Sex>
  <Age>25</Age>
</Student>

2、使用XmlAttribute修饰类属性，则对应属性序列化为节点属性

using System.Xml.Serialization;

namespace Entity
{
    public class Student
    {
        [XmlAttribute]
        public string Name { get; set; }
        [XmlAttribute]
        public string Sex { get; set; }
        [XmlAttribute]
        public int Age { get; set; }
    }
}

Student stu = new Student()
            {
                Name = "LiLei",
                Age = 25,
                Sex = "男"
            };
string xml= XmlHelper.XmlSerialize(stu, Encoding.UTF8);

序列化结果：

<!--被XmlAttribute修饰的类属性都序列化为Xml节点属性-->
<?xml version="1.0" encoding="utf-8"?>
<Student xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" Name="LiLei" Sex="男" Age="25" />

3、使用XmlText修饰为xml节点InnerText

public class Student
    {
        [XmlText]
        public string Name { get; set; }
        
        [XmlAttribute]
        public string Sex { get; set; }

        [XmlAttribute]
        public int Age { get; set; }
    }

 Student stu = new Student()
            {
                Name = "LiLei",
                Age = 25,
                Sex = "男"
            };
 string xml= XmlHelper.XmlSerialize(stu, Encoding.UTF8);

序列化结果

<?xml version="1.0" encoding="utf-8"?>
<Student xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" Sex="男" Age="25">
　　LiLei
</Student>

4、重命名

属性：[XmlAttribute("别名")]

元素节点：[XmlElement("别名")]

列表元素节点：[XmlArrayItem("别名")]

列表元素自身：[XmlArray("别名")]

类型即根节点：[XmlType("别名")]或[XmlRoot("别名")]

[XmlType("Stu")]
public class Student
    {
        [XmlElement("Name")]//重命名为Name
        public string StudentName { get; set; }
        
        [XmlAttribute("Sex")]//重命名为Sex
        public string StudentSex { get; set; }

        [XmlAttribute]
        public int Age { get; set; }
    }
Student stu = new Student()
            {
                StudentName = "LiLei",
                Age = 25,
                StudentSex = "男"
            };
 string xml= XmlHelper.XmlSerialize(stu, Encoding.UTF8);

序列化结果：

<Stu xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" Sex="男" Age="25">
  <Name>LiLei</Name>
</Stu>

 5、列表和数组在序列 

例如：
public class Student
    {
        [XmlElement("Name")]
        public string StudentName { get; set; }
        
        [XmlAttribute("Sex")]
        public string StudentSex { get; set; }

        [XmlAttribute]
        public int Age { get; set; }
    }

List<Student> stu_list = new List<Student>() {
                new Student() { StudentName = "Lily", Age = 19, StudentSex = "女" },
                new Student() { StudentName = "Hanmeimei", Age = 21, StudentSex = "女" },
                new Student() { StudentName = "Linda", Age = 19, StudentSex = "女" },
            };

string xml = XmlHelper.XmlSerialize(stu_list, Encoding.UTF8);

序列化xml结果为：

<?xml version="1.0" encoding="utf-8"?>
<ArrayOfStudent xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Student Sex="女" Age="19">
    <Name>Lily</Name>
  </Student>
  <Student Sex="女" Age="21">
    <Name>Hanmeimei</Name>
  </Student>
  <Student Sex="女" Age="19">
    <Name>Linda</Name>
  </Student>
</ArrayOfStudent>

该结果的根节点显然不大友好，为此可以重新定义一个新类型，例如：

[XmlRoot("Students")]
public class StudentList : List<Student> { }

StudentList stulist = new StudentList() {
                new Student() { StudentName = "Lily", Age = 19, StudentSex = "女" },
                new Student() { StudentName = "Hanmeimei", Age = 21, StudentSex = "女" },
                new Student() { StudentName = "Linda", Age = 19, StudentSex = "女" }
            };

string xml = XmlHelper.XmlSerialize(stulist, Encoding.UTF8);

序列化为Xml结果如下：

<?xml version="1.0" encoding="utf-8"?>
<Students xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Student Sex="女" Age="19">
    <Name>Lily</Name>
  </Student>
  <Student Sex="女" Age="21">
    <Name>Hanmeimei</Name>
  </Student>
  <Student Sex="女" Age="19">
    <Name>Linda</Name>
  </Student>
</Students>

6、类成员为数组或列表的序列化

注意：数组和列表都在序列化时，默认情况下会根据类型中的数据成员名称生成一个节点， 列表项会生成子节点，如果要重命名，可以使用[XmlArrayItem]和[XmlArray]来实现。 还可以直接用[XmlElement]控制不生成列表的父节点

例如：

 public class QueClient
    {
        public string IP { get; set; }

        public  int  LocalPort{ get; set; }

        public List<Queue> Queues { get; set; }

    }

    public class Queue
    {
        [XmlAttribute("Name")]
        public string QueueName { get; set; }
        [XmlAttribute("Id")]
        public string QueueId { get; set; }
        [XmlAttribute("Prefix")]
        public string QuePrefix { get; set; }

    }

  List<Queue> quelist = new List<Queue>()
            {
                new Queue() {QueueName="金卡",QueueId="A",QuePrefix="A" },
                new Queue() {QueueName="普卡",QueueId="B",QuePrefix="B" },
                new Queue() {QueueName="葵花卡",QueueId="C",QuePrefix="C" },
            };
            QueClient queClient = new QueClient() {
                IP ="99.12.53.71",
                LocalPort =88,
                Queues =quelist
            };

 string xml = XmlHelper.XmlSerialize(queClient, Encoding.UTF8);

序列化结果：

<?xml version="1.0" encoding="utf-8"?>
<QueClient xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <IP>99.12.53.71</IP>
  <LocalPort>88</LocalPort>
  <Queues>
    <Queue Name="金卡" Id="A" Prefix="A" />
    <Queue Name="普卡" Id="B" Prefix="B" />
    <Queue Name="葵花卡" Id="C" Prefix="C" />
  </Queues>
</QueClient>

假如QueClient成员Queues（是列表类型）机该列表节点名需重名，即Queues节点与Queue节点需要重名，只需修改QueueClient,如下：

  public class QueClient
    {
        public string IP { get; set; }

        public  int  LocalPort{ get; set; }

        [XmlArrayItem("Que")]//重命名列表节点名称
        [XmlArray("Ques")]//重命名列表根节点名称
        public List<Queue> Queues { get; set; }

    }

 List<Queue> quelist = new List<Queue>()
            {
                new Queue() {QueueName="金卡",QueueId="A",QuePrefix="A" },
                new Queue() {QueueName="普卡",QueueId="B",QuePrefix="B" },
                new Queue() {QueueName="葵花卡",QueueId="C",QuePrefix="C" },
            };
            QueClient queClient = new QueClient() {
                IP ="99.12.53.71",
                LocalPort =88,
                Queues =quelist
            };

 string xml = XmlHelper.XmlSerialize(queClient, Encoding.UTF8);

序列化结果如下：

<?xml version="1.0" encoding="utf-8"?>
<QueClient xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <IP>99.12.53.71</IP>
  <LocalPort>88</LocalPort>
  <Ques>
    <Que Name="金卡" Id="A" Prefix="A" />
    <Que Name="普卡" Id="B" Prefix="B" />
    <Que Name="葵花卡" Id="C" Prefix="C" />
  </Ques>
</QueClient>

7、类继承与反序列化

 列表元素可以是同一种类型，也可以不是同一种类型（某个类型的派生类）

例如：思考如何反序列化

<?xml version="1.0" encoding="utf-8"?>
<XRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <List>
    <X1 aa="1" bb="2" />
    <X1 aa="3" bb="4" />
    <x2>
      <cc>ccccccccccccccccc</cc>
      <dd>dddddddddd</dd>
    </x2>
  </List>
</XRoot>

思想：列表里不同类型的继承同一个父类且同时为列表成员指定多个[XmlArrayItem(typeof(XXX))]可实现多种派生类型混在一起输出。最后反序列化结果如下：

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

namespace Entity
{
    public class XBase { }

    [XmlRoot("x1")]
    public class X1 : XBase
    {
        [XmlAttribute("aa")]
        public String AA { get; set; }
        [XmlAttribute("bb")]
        public string BB { get; set; }

    }

    [XmlType("x2")]
    public class X2 : XBase
    {
        [XmlElement("cc")]
        public string CC { get; set; }
        [XmlElement("dd")]
        public string DD { get; set; }
    }

    public class XRoot
    {
        [XmlArrayItem(typeof(X1))]//注意此处指出节点类型两个X1，X2
        [XmlArrayItem(typeof(X2))]//注意此处指出节点类型两个X1，X2
        public List<XBase> List { get; set; }
    }
}

 例如：反序列化如下xml内容：

<DynamicHelp xmlns="http://msdn.microsoft.com/vsdata/xsd/vsdh.xsd" 
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
            xsi:schemaLocation="http://msdn.microsoft.com/vsdata/xsd/vsdh.xsd vsdh.xsd">
    <LinkGroup ID="sites" Title="Venus Sites" Priority="1500">
        <Glyph Collapsed="3" Expanded="4"/>
    </LinkGroup>
    <LinkGroup ID="Venus Private Forums" Title="Venus Private Forums" Priority="1400">
        <Glyph Collapsed="3" Expanded="4"/>
    </LinkGroup>
    <LinkGroup ID="ASP.NET Forums" Title="ASP.NET 1.0 Public Forums" Priority="1200">
        <Glyph Collapsed="3" Expanded="4"/>
    </LinkGroup>
    <Context>
        <Links>
            <LItem URL="http://www.asp.net/venus" LinkGroup="sites">Venus Home Page</LItem>
            <LItem URL="http://www.asp.net" LinkGroup="sites">ASP.NET Home Page</LItem>
            <LItem URL="http://www.asp.net/Forums/ShowForum.aspx?tabindex=1&amp;ForumID=77" 
                    LinkGroup="Venus Private Forums">General Discussions</LItem>
            <LItem URL="http://www.asp.net/Forums/ShowForum.aspx?tabindex=1&amp;ForumID=83" 
                    LinkGroup="Venus Private Forums">Feature Requests</LItem>
            <LItem URL="http://www.asp.net/Forums/ShowForum.aspx?tabindex=1&amp;ForumID=78" 
                    LinkGroup="Venus Private Forums">Bug Reports</LItem>
            <LItem URL="http://www.asp.net/Forums/ShowForum.aspx?tabindex=1&amp;ForumID=86" 
                    LinkGroup="Venus Private Forums">ASP.NET 2.0 Related issues</LItem>
            <LItem URL="http://www.asp.net/Forums/ShowForum.aspx?tabindex=1&amp;ForumID=11" 
                    LinkGroup="ASP.NET Forums">Announcements</LItem>
            <LItem URL="http://www.asp.net/Forums/ShowForum.aspx?tabindex=1&amp;ForumID=15" 
                    LinkGroup="ASP.NET Forums">Getting Started</LItem>
            <LItem URL="http://www.asp.net/Forums/ShowForum.aspx?tabindex=1&amp;ForumID=18" 
                    LinkGroup="ASP.NET Forums">Web Forms</LItem>
        </Links>
    </Context>
</DynamicHelp>

反序列化为：

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

namespace Entity
{
    [XmlRoot(Namespace = "http://msdn.microsoft.com/vsdata/xsd/vsdh.xsd")]//注意此处与xml内容一致,xml内容有空间限定时类定义也需添加
    public class DynamicHelp
    {
        [XmlElement]//注意此处
        public List<LinkGroup> Groups { get; set; }

        public Context Context { get; set; }
    }

    public class LinkGroup {
        [XmlAttribute]
        public string ID { get; set; }
        [XmlAttribute]
        public string Title { get; set; }
        [XmlAttribute]
        public int Priority { get; set; }

        public Glyph Glyph { get; set; }
    }

    public class Glyph
    {
        [XmlAttribute]
        public int Collapsed { get; set; }
        [XmlAttribute]
        public int Expanded { get; set; }
    }


    public class LItem
    {
        [XmlAttribute]
        public string URL { get; set; }
        [XmlAttribute]
        public string LinkGroup { get; set; }

        [XmlText]
        public string Title { get; set; }
    }

    public class Context {
        public List<LItem> Links { get; set; }
    }
}

 8、不需要序列化的属性： [XmlIgnore]

 public class QueClient
    {
        public string IP { get; set; }
        public  int  LocalPort{ get; set; }
        [XmlIgnore]
        public int LocalPort2{ get; set; }
        [XmlElement]
        public List<Queue> Queues { get; set; }

    }

9、指定类成员序列化顺序[XmlElement(Order<= 顺序数字)]

 例如：

  public class QueClient
    {
        [XmlElement(Order =2)]//设置序列化顺序
        public string IP { get; set; }
        
        public  int  LocalPort{ get; set; }

        [XmlIgnore]
        public int LocalPort2{ get; set; }

        [XmlElement]
        public List<Queue> Queues { get; set; }

    }

10、序列化去掉命名空间及声明

 private static void XmlSerializeInternal(Stream stream,object obj,Encoding encoding)
        {
            if (obj == null)
                throw new ArgumentNullException("object");
            if(encoding==null)
                throw new ArgumentNullException("object");
            XmlSerializer serializer = new XmlSerializer(obj.GetType());

            XmlWriterSettings settings = new XmlWriterSettings();
            settings.Indent = true;
            settings.NewLineChars = "
";
            settings.Encoding = encoding;
            settings.IndentChars = "  ";
            //设置忽略声明空间
            settings.OmitXmlDeclaration = true;
            // 强制指定命名空间，覆盖默认的命名空间。
            XmlSerializerNamespaces namespaces = new XmlSerializerNamespaces();
            namespaces.Add(string.Empty, string.Empty);

            using (XmlWriter writer=XmlWriter.Create(stream, settings))
            {
                serializer.Serialize(writer, obj,namespaces);
            }
        }

11、自定义序列化行为

假如如下代码序列化：

    public class TestClass
    {
        public string StrValue { get; set; }

        public List<int> List { get; set; }
    }

    public class ClassB1
    {
        public TestClass Test { get; set; }
    }

TestClass test = new TestClass { 
    StrValue = "Fish Li", 
    List = new List<int> { 1, 2, 3, 4, 5 } 
  };
 ClassB1 b1 = new ClassB1 { Test = test };
 string xmbll = XmlHelper.XmlSerialize(b1, Encoding.UTF8);

序列化结果：

<ClassB1>
  <Test>
    <StrValue>Fish Li</StrValue>
    <List>
      <int>1</int>
      <int>2</int>
      <int>3</int>
      <int>4</int>
      <int>5</int>
    </List>
  </Test>
</ClassB1>

但实际需求是序列化为如下：

<ClassB1 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <Test s="Fish Li">1,2,3,4,5</Test>
</ClassB1>

此时只需要对需要特殊序列化的类进行重定义，即该类实现IXmlSerializable重写ReadXml与WriteXml方法

public class TestClass: IXmlSerializable
    {
        public string StrValue { get; set; }

        public List<int> List { get; set; }

        public XmlSchema GetSchema()
        {
            return null;
        }

        public void ReadXml(XmlReader reader)
        {
            StrValue = reader.GetAttribute("s");
            string numbers = reader.ReadString();
            if(string.IsNullOrWhiteSpace(numbers)==false)
                List = (from s in numbers.Split(new char[] {','}, StringSplitOptions.RemoveEmptyEntries)
                        let n = int.Parse(s)
                        select n).ToList();
        }

        public void WriteXml(XmlWriter writer)
        {
            writer.WriteAttributeString("s", StrValue);
            writer.WriteString(string.Join(",", List.ConvertAll<string>(x => x.ToString()).ToArray()));
        }
    }