本文主要是介绍.NET XML 串行化讲座，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
1,浅串行化：只串行化类的公共字段和属性
公共属性必须是可读且可写的
使用命名空间：using System.Xml.Serialization;
以Book类为例：
串行化模板：
public void SerializeIt( string filename)
{
XmlSerializer serializer = new XmlSerializer(typeof(Book)); StreamWriter writer = new StreamWriter(filename); Book myBook = new Book(); serializer.Serialize(writer, myBook); writer.Close();
}
反串行化模板：
public void DeserializeIt( string filename) { XmlSerializer serializer = new XmlSerializer(typeof(Book)); FileStream fs = new FileStream(filename, FileMode.Open); Book myBook = (Book)serializer.Deserialize(fs); fs.Close(); }
*使用XmlSerializer的类必须有一个不带参数的默认构造函数——在反串行化中使用
*序列化ArrayList类型字段X的特殊处理：在ctor中 this.X = new ArrayList();
*对于引用关系，如果A中引用了B，那么
在序列化A的时候，会生成如下格式的XML：
<A>
<B>xxxxx</B>
</A>
在反序列化A对象的时候，A中也会包含有具体值的B对象
*浅序列化不支持循环引用，即A引用B的同时，B也引用了A
序列化时，将XML格式定制为SOAP格式：使用XmlSerializer构造函数的另一个重载：
public void SerializeIt( string filename) { SoapReflectionImporter import = new SoapReflectionImporter(); XmlTypeMapping soapMapping = import.ImportTypeMapping(typeof(Book)); XmlSerializer serializer = new XmlSerializer(soapMapping); StreamWriter writer = new StreamWriter(filename); Book myBook = new Book(); serializer.Serialize(writer, myBook); writer.Close(); }
2,深串行化：串行化对象的整个状态
使用命名空间：
using System.IO; using System.Runtime.Serialization; using System.Runtime.Serialization.Formatters.Binary; using System.Runtime.Serialization.Formatters.Soap;
串行化类的标志：在类前加上[Serializable]特性
两种格式器：BinaryFormatter，SoapFormatter
以BinaryFormatter为例(SoapFormatter与之相同)
串行化模板：
public void SerializeIt( string filename) { Book myBook = new Book(); BinaryFormatter formatter = new BinaryFormatter(); FileStream fs = File.Create(filename); formatter.Serialize(fs, myBook); fs.Close(); }
反串行化模板：
public void DeserializeIt( string filename) { BinaryFormatter formatter = new BinaryFormatter(); FileStream fs = File.OpenRead(filename); Book myBook = (Book)formatter.Deserialize(fs); fs.Close(); }
*在字段上加上[NonSerialized]，可以不使该字段被序列化
*对于引用关系，如果A中引用了B，A和B类都要加上[Serializable]，才能对A进行串行化
*对于循环引用，只支持对象图的循环引用，不支持广义的对象循环引用
对象图循环引用的例子：
[Serializable] public class Book { private BookCatalog includeInBookCatalog; public BookCatalog IncludeInBookCatalog
{
get { return includeInBookCatalog; } set { includeInBookCatalog = value; }
} } [Serializable] public class BookCatalog { private Book[] books; public Book[] Books { get { return books; } set { books = value; foreach (Book book in books) { book.IncludeInBookCatalog = this; } } } }
对BookCatalog进行深度序列化，不会造成循环引用，因为格式化器Formatter知道无论对象有多少个引用，保证每个对象只串行化一次——通过System.Runtime.Serialization下的两个类实现：ObjectManager和ObjectIDGenerator。
ObjectManager 负责在对象反串行化时跟踪对象，确定该对象是否串行化过
ObjectIDGenerator 为每个被跟踪的对象加一个唯一的ID以区别，根据对象是否被串行化，ObjectIDGenerator知道是返回已有的ID，还是生成一个新的ID
格式化器不会提前检查所有的对象可串行化，中途如果发生异常，可以已经生成部分对象了。
通过深串行化克隆对象：
先串行化，在内存流上使用二进制深度复制；然后再找到流的开头，进行反串行化
public object Clone( object source) { MemoryStream stream = new MemoryStream(); BinaryFormatter formatter = new BinaryFormatter(); formatter.Context = new StreamingContext(StreamingContextStates.Clone); formatter.Serialize(stream, source); stream.Position = 0; return formatter.Deserialize(stream); }
3, 3.1 从可串行化的类中定制XML串行化
1.格式化XML文档元素
[XmlRoot(ElementName = " Pupil " , Namespace = " urn:MyNamespace " )] public class Student { //则生成XML文档中，根元素<Pupil xmlns="urn:MyNamespace"> }
2.格式化XML元素
[XmlElement(ElementName = " FullName " , Namespace = " urn:OtherNamespace " )] public string Name { get { return name; } set { name = value; } }
生成XML如下：
<? xml version = " 1.0 " encoding = " utf-8 " ?> < Pupil xmlns:xsd = " http://www.w3.org/2001/XMLSchema " xmlns:d1p1 = " urn:OtherNamespace " > < d1p1:FullName > Thomas Smith </ d1p1:FullName > </ Pupil >
这里的d1p1是自动生成的，在标题4，有办法自己指定Namespace前缀。
3.格式化XML属性
[XmlAttribute(AttributeName = " StudentNumber " , Namespace = " urn:MyNamespace " )] public string Name { get { return name; } set { name = value; } }
同样还是Name属性，这次是使用XmlAttribute标签，生成XML如下：
<? xml version = " 1.0 " encoding = " utf-8 " ?> < Pupil xmlns:xsd = " http://www.w3.org/2001/XMLSchema " xmlns:d1p1 = " urn:OtherNamespace " d1p1:Name = " Thomas Smith " > </ Pupil >
XML属性在空间利用率上比XML元素略高一些。
4.为元素/属性设计限定的命名空间
使用XmlSerializer的Serialize方法重载，额外带一个XmlSerializerNamespace参数，指定这个命名空间前缀
public void SerializeIt( string filename) { //自定义命名空间 XmlSerializerNamespaces ns = new XmlSerializerNamespaces(); ns.Add("xsd", "http://www.w3.org/2001/XMLSchema"); ns.Add("xsi", "http://www.w3.org/2001/XMLSchema-instance"); ns.Add("otherNS", "urn:OtherNamespace"); XmlSerializer serializer = new XmlSerializer(typeof(Book)); StreamWriter writer = new StreamWriter(filename); Book myBook = new Book(); //使用Serialize重载方法 serializer.Serialize(writer, myBook, ns); writer.Close(); }
从而生成完全自定义的XML：
<? xml version = " 1.0 " encoding = " utf-8 " ?> < Pupil xmlns:xsd = " http://www.w3.org/2001/XMLSchema " xmlns:otherNS = " urn:OtherNamespace " xmlns:xsi = " http://www.w3.org/2001/XMLSchema-instance " otherNS:StudentNumber = " 8007 " xmlns = " urn:MyNamespace " > < otherNS:FullName > Thomas Smith </ otherNS:FullName > </ Pupil >
5.格式化文本内容
[XmlText()] public string Name { get { return name; } set { name = value; } }
则Name会生成在<Pupil>XXX(Name)</Pupil>中作为文本
6.为元素/属性定义数据类型
XML Schema类型与.NET数据类型有一个Mapping，比如说type对应System.DateTime
[XmlElement(DataType = " date " )] public DateTime EnrollDate { get { return enrollDate; } set { enrollDate = value; } }
于是生成XML： <EnrollDate>2007-10-19</EnrollDate>
XMLRoot，XmlAttribute，XMLElement，XMLText，XMLArrayItem标签都可以指定DataType
7.为枚举修饰符指定其他名称
public enum Color { [XmlEnum(Name="White Color")] White, [XmlEnum(Name = "Black Color")] Black, [XmlEnum(Name = "Red Color")] Red } private Color showColor; public Color ShowColor { get { return showColor; } set { showColor = value; } }
生成XML如下格式：
<ShowColor>White Color</ShowColor>
8.串行化多肽数组
[XmlArray(ElementName = " Cources " ), XmlArrayItem(Type = typeof (String), ElementName = " CourceName " ), XmlArrayItem(Type = typeof (Int32), ElementName = " CourceCode " )] public Object[] Subjects { get { return subjects; } set { subjects = value; } }
XmlArrayItem负责指定数组中可能出现的元素类型，以及该类型对应的XML前缀
比如说创建如下的数组：
Object obj = new Object["Physics", 123, "IT"];
生成XML如下格式：
< Cources > < CourceName > Physics </ CourceName > < CourceCode > 123 </ CourceCode > < CourceName > IT </ CourceName > </ Cources >
9.定义可空的对象引用
如果某属性为null，在串行化时会忽略该属性，可以显示替代的信息，方法如下：
[XmlElement(IsNullable = true )] public string Address { get { return address; } set { address = value; } }
在该位置，生成替代XML：
<Address xsi:nil="true" />
10.定义可忽略的字段/属性
[XmlIgnore()]
3.2 把XML串行化定制为SOAP编码格式
public void MySerialize(Student obj, string filename) { SoapReflectionImporter importer = new SoapReflectionImporter(); XmlTypeMapping mapping = importer.ImportMembersMapping(typeof(Student)); XmlTextWriter writer = new XmlTextWriter(filename, System.Text.Encoding.UTF8); writer.WriteStartElement("MyWrapperElement"); writer.WriteAttributeString("xmlns", "xsd", Nothing, "http://www.w3.org/2001/XMLSchema"); writer.WriteAttributeString("xmlns", "xsi", Nothing, "http://www.w3.org/2001/XMLSchema-instance"); writer.WriteAttributeString("xmlns", "soap", Nothing, "http://schemas.xmlsoap.org/soap/encoding/"); writer.WriteAttributeString("xmlns", "otherNS", Nothing, "urn:OtherNamespace"); XmlSerializer serializer = new XmlSerializer(mapping); serializer.Serialize(writer, obj); writer.WriteEndElement(); writer.Close(); }
于是，生产SOAP格式的XML文件。
Soap编码串行化的属性，无XMLText和XMLArray，其它的对应如下：
| SoapType | XmlType |
| SoapElement | XmlElement |
| SoapAttribute | XmlAttribute |
| SoapEnum | XmlEnum |
| SoapIgnore | XmlIgnore |
| SoapInclude | XmlInclude |
这篇关于.NET XML 串行化讲座的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
