序列化(一):XMLSerilize

http://www.codeproject.com/KB/XML/Serialization_Samples.aspx
如果类实现了IDictionary,就不能被序列化。如：Hashtables cannot be serialized.

By using XML serialization only public properties and fields can be serialized. If private members are to be serialized, other serialization methods should be used.

It requires a parameterless constructor. This constructor is called during deserialization.

Serialized form of the object does not contain any type, assembly information of the class. Only the data is stored.

Using XML serialization not all the classes can be serialized. Classes that implement IDictionary cannot be serialized. E.g. Hashtables cannot be serialized. Arrays of objects can be easily serialized. Collections can be serialized but to serialize collections certain rules must be followed.

Null values are not serialized with XML serialization. To include the null members in the serialized form IsNullable attribute should be set to true. For example:

[ XmlElement( IsNullable = true ) ]
去掉xmlns：

XmlSerializerNamespaces namespaces  =   new  XmlSerializerNamespaces();
namespaces.Add( string .Empty,  string .Empty);            
serializer.Serialize(writer, source, namespaces);

改变根元素的名字:RootName

XmlRootAttribute root  =   new  XmlRootAttribute();
root.ElementName  =  name;
XmlSerializer xs  =   new  XmlSerializer( typeof (T), root);

格式化序列化类中嵌套类的属性：

 [XmlArrayItem(Type = typeof (NetAtt),ElementName = " item " )]
     public  List < NetAtt >  NetAtts;

你也可以自定义XMLTextWriter 去掉XML Declaration.<?xml version="1.0" encoding="utf-8" ?>

public   class  SpecialXmlWriter : XmlTextWriter
{
     bool  m_includeStartDocument  =   true ;
     public  SpecialXmlWriter(TextWriter tw,  bool  includeStartDocument)
        :  base (tw)
    {
        m_includeStartDocument  =  includeStartDocument;
    }
     public  SpecialXmlWriter(Stream sw, Encoding encoding,  bool  includeStartDocument)
        :  base (sw,  null )
    {
        m_includeStartDocument  =  includeStartDocument;
    }
     public  SpecialXmlWriter( string  filePath, Encoding encoding,  bool  includeStartDocument)
        :  base (filePath,  null )
    {
        m_includeStartDocument  =  includeStartDocument;
    }
     public   override   void  WriteStartDocument()
    {
         if  (m_includeStartDocument)
        {
             base .WriteStartDocument();
        }
    }
}

测试如下：

XmlSerializer serializer  =   null ;
        SpecialXmlWriter swriter  =   null ;
         try
        {
            serializer  =   new  XmlSerializer(objXml.GetType());
            swriter  =   new  SpecialXmlWriter(Server.MapPath( " ~/a.xml " ), System.Text.Encoding.Default,  false );
             if  ( ! isNameSpaces)
            {
                XmlSerializerNamespaces xNamesSpace  =   new  XmlSerializerNamespaces();
                xNamesSpace.Add( "" ,  "" );
                serializer.Serialize(swriter, objXml, xNamesSpace);
            }
             else
                serializer.Serialize(swriter, objXml);
        }
         catch  (Exception ex)
        {
             throw   new  Exception(ex.ToString());
        }
         finally
        {
             if  (swriter  !=   null )
            {
                swriter.Close();
            }
        }

//

using  System;
using  System.Collections.Generic;
using  System.Linq;
using  System.Web;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.Xml.Serialization;
using  System.IO;
using  System.Runtime.Serialization;
using  System.Xml;
public   partial   class  Default2 : System.Web.UI.Page
{
     protected   void  Page_Load( object  sender, EventArgs e)
    {
        
    }
     protected   void  Button1_Click( object  sender, EventArgs e)
    {
        List < GaryPerson >  objlist  =   new  List < GaryPerson > (){
          new  GaryPerson{ strPassword = " 张三 " , strUserName = " P " }
        };
        Serialize(objlist, Server.MapPath( " ~/obj.xml " ));
         
    }
     void  Serialize( object  source,  string  file)
    {
        XmlWriterSettings settings  =   new  XmlWriterSettings();
        settings.OmitXmlDeclaration  =   true ;
        settings.Indent  =   true ;
         
         using  (XmlWriter writer  =  XmlWriter.Create(file, settings))
        {
            XmlRootAttribute root  =   new  XmlRootAttribute( " GaryList " );
            XmlSerializer serializer  =   new  XmlSerializer(source.GetType(),root);
           
            XmlSerializerNamespaces namespaces  =   new  XmlSerializerNamespaces();
            namespaces.Add( string .Empty,  string .Empty);
             
            serializer.Serialize(writer, source, namespaces);
        }
    }
    
}
[Serializable]
public   class  GaryPerson
{
     public   string  strUserName;
     public   string  strPassword;
}