3.设计用于浅串行化的类

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