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  • Convert XML data to object and back using serialization

    Introduction

    Saving XML to a class object gives greater flexibility and maintainability. Moreover, it�s the preferred way of returning data from web services as compared to using DataSets. Saving XML to a class object is called serialization and reading back using the reverse process is named as deserialization.

    Process\sample

    Let's take an example of an XSD named Emp.XSD:

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    <?xml version="1.0" encoding="UTF-8"?>
    <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" 
         elementFormDefault="qualified" attributeFormDefault="unqualified">
     <xs:element name="Emp">
      <xs:complexType>
       <xs:sequence>
        <xs:element name="EmpInfo" type="EmpInfo"/>
       </xs:sequence>
      </xs:complexType>
     </xs:element>
     <xs:complexType name="EmpInfo">
      <xs:sequence>
       <xs:element name="Code" type="requiredString"/>
       <xs:element name="FirstName" type="requiredString"/>
       <xs:element name="LastName" type="requiredString"/>
       <xs:element name="Destination" type="requiredString"/>
      </xs:sequence>
     </xs:complexType>
     <xs:simpleType name="requiredString">
      <xs:annotation>
       <xs:documentation>template for required strings</xs:documentation>
      </xs:annotation>
      <xs:restriction base="xs:string">
       <xs:minLength value="1"/>
      </xs:restriction>
     </xs:simpleType>
     <xs:simpleType name="optionalString">
      <xs:annotation>
       <xs:documentation>template for optional strings</xs:documentation>
      </xs:annotation>
      <xs:restriction base="xs:string">
       <xs:minLength value="0"/>
      </xs:restriction>
     </xs:simpleType>
    </xs:schema>

    Now, to convert a class from XSD, we would run the following command:

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    xsd C:\Emp.xsd /t:lib /l:cs /c

    from the Visual Studio .NET 2003 command prompt. This would create a class file named Emp.

    EMP Class

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    //------------------------------------------------------------------------------
    // <autogenerated>
    //     This code was generated by a tool.
    //     Runtime Version: 1.1.4322.2032
    
    //
    //     Changes to this file may cause incorrect behavior and will be lost if 
    //     the code is regenerated.
    // </autogenerated>
    //------------------------------------------------------------------------------
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    // 
    // This source code was auto-generated by xsd, Version=1.1.4322.2032.
    // 
    using System.Xml.Serialization;
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    /// <remarks/>
    [System.Xml.Serialization.XmlRootAttribute(Namespace="", IsNullable=false)]
    public class Emp {
        
        /// <remarks/>
        public EmpInfo EmpInfo;
    }
    
    /// <remarks/>
    public class EmpInfo {
        
        /// <remarks/>
        public string Code;
        
        /// <remarks/>
        public string FirstName;
        
        /// <remarks/>
        public string LastName;
        
        /// <remarks/>
        public string Destination;
    }

    Now, we could save an employee XML data to this class using the function:

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      /// <summary>
      /// Returns an emp xsd class object based on the xml data passed
      /// </summary>
      /// <param name="xml">xml data of employee</param>
      /// <returns></returns>
      public Emp EmpObject(string xml)
      {
       StringReader stream = null;
       XmlTextReader reader = null;
       try
       {
        // serialise to object
        XmlSerializer serializer = new XmlSerializer(typeof(Emp));
        stream = new StringReader(xml); // read xml data
        reader = new XmlTextReader(stream);  // create reader
        // covert reader to object
        return (Emp)serializer.Deserialize(reader);
       }
       catch
       {
        return null;
       }
       finally
       {
        if(stream != null) stream.Close();
        if(reader != null) reader.Close();
       }
      }

    And to get the XML based on the Emp class object, use the following function:

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      /// <summary>
      /// Returns the xml as string based on emp object values
      /// </summary>
      /// <param name="emp">object that would be converted into xml</param>
      /// <returns></returns>
      public string EmpXml(Emp emp)
      {
       MemoryStream stream = null;
       TextWriter writer = null;
       try
       {
        stream = new MemoryStream(); // read xml in memory
        writer = new StreamWriter(stream, Encoding.Unicode) ;
        // get serialise object
        XmlSerializer serializer = new XmlSerializer(typeof(Emp));
        serializer.Serialize(writer, emp); // read object
        int count = (int) stream.Length; // saves object in memory stream
        byte[] arr = new byte[count];
        stream.Seek(0, SeekOrigin.Begin);
        // copy stream contents in byte array
        stream.Read(arr, 0, count);
        UnicodeEncoding utf = new UnicodeEncoding(); // convert byte array to string
        return utf.GetString(arr).Trim();
       }
       catch
       {
        return string.Empty;
       }
       finally
       {
        if(stream != null) stream.Close();
        if(writer != null) writer.Close();
       }
      }

    License

    This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

    A list of licenses authors might use can be found here

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  • 原文地址:https://www.cnblogs.com/likwo/p/1659545.html
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