C# xml数组的序列和反序列化

先来看xml

<?xml version="1.0"?>
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Person>
    <Name>小莫</Name>
    <Age>20</Age>
    <Books>
      <Book>
        <Title>马列主义</Title>
        <ISBN>SOD1323DS</ISBN>
      </Book>
    </Books>
  </Person>
  <Person>
    <Name>小红</Name>
    <Age>20</Age>
    <Books>
      <Book>
        <Title>思想</Title>
        <ISBN>SID1323DSD</ISBN>
      </Book>
    </Books>
  </Person>
</root>

这个xml包含多个Person对象，每个Person对象又包含一个Books对象和多个book对象，反序列化XML时关键是看怎么理解xml的结构，理解正确了就很好构造对应的类，理解错了可能就陷入坑里。

首先root是整个文件的根节点，它是由多个Person组成的。

[System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    [System.Xml.Serialization.XmlRootAttribute("root", IsNullable = false)]
    public class BaseInfo
    {
        [System.Xml.Serialization.XmlElementAttribute("Person")]
        public List<Person> PersonList { get; set; }
    }

再看Person对象，Person是由name和age两个属性和一个Books对象组成，Person可以定义成

[System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    [System.Xml.Serialization.XmlRootAttribute("Person", IsNullable = false)]
    public class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }

        [System.Xml.Serialization.XmlElementAttribute("Books")]
        public Books Books { get; set; }
    }

这里理解的关键是把下面这小段xml理解成一个包含多个Book的对象，而不是把它理解成book的数组

    <Books>
      <Book>
        <Title>毛泽思想</Title>
        <ISBN>SID1323DSD</ISBN>
      </Book>
    </Books>

如果把她理解成一个数据就容易把Person定义成

[System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    [System.Xml.Serialization.XmlRootAttribute("Person", IsNullable = false)]
    public class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }

        [System.Xml.Serialization.XmlElementAttribute("Books")]
        public List<Book> Books { get; set; }
    }

而book的定义如下

　　 [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    [System.Xml.Serialization.XmlRootAttribute("Book", IsNullable = false)]
    public class Book
    {
        public string Title { get; set; }
        public string ISBN { get; set; }
    }

序列化生成的xml不包含Book节点

，生成的xml如下

<?xml version="1.0"?>
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Person>
    <Name>小莫</Name>
    <Age>20</Age>
    <Books>

        <Title>马列主义</Title>
        <ISBN>SOD1323DS</ISBN>

    </Books>
  </Person>
  <Person>
    <Name>小红</Name>
    <Age>20</Age>
    <Books>
        <Title>毛泽思想</Title>
        <ISBN>SID1323DSD</ISBN>

    </Books>
  </Person>
</root>

之所以出现上面的情况是因为：

public List<Book> Books { get; set; }
和Book同属一个节点层次，在List<Book> Books上显式指定了属性名称Books，那么这个节点就是Books,跟Book上定义指定的[System.Xml.Serialization.XmlRootAttribute("Book", IsNullable = false)]
没有关系，它是用来指示Book是跟节点时的名称。
或者可以这样理解xml是由多个节点组成的，而Book类定义不是一个节点，它只是一个定义，要想xml中出现book,就需要再加一个节点，我们把Person节点加到Books对象中

    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    public class Books
    {
        [System.Xml.Serialization.XmlElementAttribute("Book")]
        public List<Book> BookList { get; set; }
    }

这样就多出了一个节点，再结合刚开始的person定义就能序列化出正确的xml了

完整的代码

 [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    [System.Xml.Serialization.XmlRootAttribute("root", IsNullable = false)]
    public class BaseInfo
    {
        [System.Xml.Serialization.XmlElementAttribute("Person")]
        public List<Person> PersonList { get; set; }
    }

    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    [System.Xml.Serialization.XmlRootAttribute("Person", IsNullable = false)]
    public class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }

        [System.Xml.Serialization.XmlElementAttribute("Books")]
        public Books Books { get; set; }
    }

    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    public class Books
    {
        [System.Xml.Serialization.XmlElementAttribute("Book")]
        public List<Book> BookList { get; set; }
    }

    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    [System.Xml.Serialization.XmlRootAttribute("Book", IsNullable = false)]
    public class Book
    {
        public string Title { get; set; }
        public string ISBN { get; set; }
    }

 static void Main(string[] args)
        {

            BaseInfo baseInfo = new BaseInfo();
            List<Person> personList = new List<Person>();
            Person p1 = new Person();
            p1.Name = "小莫";
            p1.Age = ;

            List<Book> books = new List<Book>();
            Book book = new Book();
            book.Title = "马列主义";
            book.ISBN = "SOD1323DS";
            books.Add(book);
            p1.Books = new Books();
            p1.Books.BookList = books;

            Person p2 = new Person();
            p2.Name = "小红";
            p2.Age = ;

            List<Book> books2 = new List<Book>();
            Book book2 = new Book();
            book2.Title = "毛泽思想";
            book2.ISBN = "SID1323DSD";
            books2.Add(book2);
            p2.Books =new Books();
            p2.Books.BookList = books2;

            personList.Add(p1);
            personList.Add(p2);

            baseInfo.PersonList = personList;

            string postXml2 = SerializeHelper.Serialize(typeof(BaseInfo), baseInfo);
            Console.ReadLine();
        }

    }

序列化用到的类

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

namespace ConsoleApplication1
{
    public class SerializeHelper
    {
        public static string Serialize(Type type, object o)
        {
            string result = string.Empty;
            try
            {
                XmlSerializer xs = new XmlSerializer(type);
                MemoryStream ms = new MemoryStream();
                xs.Serialize(ms, o);
                ms.Seek(, SeekOrigin.Begin);
                StreamReader sr = new StreamReader(ms);
                result = sr.ReadToEnd();
                ms.Close();
            }
            catch (Exception ex)
            {
                throw new Exception("对象序列化成xml时发生错误：" + ex.Message);
            }
            return result;
        }

        /// <summary>
        /// 序列化XML时不带默认的命名空间xmlns
        /// </summary>
        /// <param name="type"></param>
        /// <param name="o"></param>
        /// <returns></returns>
        public static string SerializeNoneNamespaces(Type type, object o)
        {
            string result = string.Empty;
            try
            {
                XmlSerializer xs = new XmlSerializer(type);
                MemoryStream ms = new MemoryStream();
                XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
                ns.Add("", "");//Add an empty namespace and empty value
                xs.Serialize(ms, o, ns);
                ms.Seek(, SeekOrigin.Begin);
                StreamReader sr = new StreamReader(ms);
                result = sr.ReadToEnd();
                ms.Close();
            }
            catch (Exception ex)
            {
                throw new Exception("对象序列化成xml时发生错误：" + ex.Message);
            }
            return result;
        }

        /// <summary>
        /// 序列化时不生成XML声明和XML命名空间
        /// </summary>
        /// <param name="type"></param>
        /// <param name="o"></param>
        /// <returns></returns>
        public static string SerializeNoNamespacesNoXmlDeclaration(Type type, object o)
        {
            string result = string.Empty;
            try
            {
                XmlSerializer xs = new XmlSerializer(type);
                MemoryStream ms = new MemoryStream();
                XmlSerializerNamespaces ns = new XmlSerializerNamespaces();

                XmlWriterSettings settings = new XmlWriterSettings();
                settings.OmitXmlDeclaration = true;//不编写XML声明
                XmlWriter xmlWriter = XmlWriter.Create(ms, settings);

                ns.Add("", "");//Add an empty namespace and empty value
                xs.Serialize(xmlWriter, o, ns);
                ms.Seek(, SeekOrigin.Begin);
                StreamReader sr = new StreamReader(ms);
                result = sr.ReadToEnd();
                ms.Close();
            }
            catch (Exception ex)
            {
                throw new Exception("对象序列化成xml时发生错误：" + ex.Message);
            }
            return result;
        }

        public static object Deserialize(Type type, string xml)
        {
            object root = new object();
            try
            {
                XmlSerializer xs = new XmlSerializer(type);
                MemoryStream ms = new MemoryStream();
                StreamWriter sw = new StreamWriter(ms);
                sw.Write(xml);
                sw.Flush();
                ms.Seek(, SeekOrigin.Begin);
                root = xs.Deserialize(ms);
                ms.Close();
            }
            catch (Exception ex)
            {
                throw new Exception("xml转换成对象时发生错误：" + ex.Message);
            }
            return root;
        }
    }
}

再看一个例子，简单数组类型的序列化

<?xml version="1.0"?>
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <barcodes>
    <barcode>AAA</barcode>
    <barcode>BBB</barcode>
  </barcodes>
</root>

我们经常搞半天不知道要怎么书写上面xml对应的类，总是容易出现上面说过的错误，关键还是看怎么理解barcodes，和上面的例子类似，这里只写类怎么创建

　　[System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    [System.Xml.Serialization.XmlRootAttribute("root", IsNullable = false)]
    public class DownLoadPDFRequest
    {

        [System.Xml.Serialization.XmlElementAttribute("barcodes")]
        public barcoders barcodes { get; set; }
    }

    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
    //[System.Xml.Serialization.XmlRootAttribute("barcoders", IsNullable = false)]
    public class barcoders
    {
        private List<string> _barcode;

        [System.Xml.Serialization.XmlElementAttribute("barcode")]
        public List<string> BarCode
        {
            get { return _barcode; }
            set { _barcode = value; }
        }

    }

 static void Main(string[] args)
        {

            DownLoadPDFRequest request = new DownLoadPDFRequest();

            List<barcoders> barcodes = new List<barcoders>();

            List<string> bars=new List<string>();
            bars.Add("AAA");
            bars.Add("BBB");
            request.barcodes = new barcoders();;
            request.barcodes.BarCode = bars;

            string postXml = SerializeHelper.Serialize(typeof(DownLoadPDFRequest), request);
}