XmlSerializer Constructor (Type, XmlAttributeOverrides) (System.Xml.Serialization)

' Beginning of HighSchool.dll
Imports System
Imports System.IO
Imports System.Xml
Imports System.Xml.Serialization
Imports Microsoft.VisualBasic
Imports HighSchool

Namespace HighSchool

    Public Class Student
        Public Name As String
        Public ID As Integer
    End Class 'Student


    Public Class MyClass1
        Public Students() As Student
    End Class 'MyClass1
End Namespace 'HighSchool

Namespace College
    Public Class Graduate
        Inherits HighSchool.Student

        Public Sub New()
        End Sub 'New ' Add a new field named University.
        Public University As String
    End Class 'Graduate



    Public Class Run

        Public Shared Sub Main()
            Dim test As New Run()
            test.WriteOverriddenAttributes("College.xml")
            test.ReadOverriddenAttributes("College.xml")
        End Sub 'Main


        Private Sub WriteOverriddenAttributes(filename As String)
            ' Writing the file requires a TextWriter.
            Dim myStreamWriter As New StreamWriter(filename)
            ' Create an XMLAttributeOverrides class.
            Dim attrOverrides As New XmlAttributeOverrides()
            ' Create the XmlAttributes class.
            Dim attrs As New XmlAttributes()

            ' Override the Student class. "Alumni" is the name
            ' of the overriding element in the XML output. 
            Dim attr As New XmlElementAttribute("Alumni", GetType(Graduate))

            ' Add the XmlElementAttribute to the collection of
            ' elements in the XmlAttributes object. 
            attrs.XmlElements.Add(attr)

            ' Add the XmlAttributes to the XmlAttributeOverrides. 
            ' "Students" is the name being overridden. 
            attrOverrides.Add(GetType(HighSchool.MyClass1), "Students", attrs)

            ' Create the XmlSerializer. 
            Dim mySerializer As New XmlSerializer(GetType(HighSchool.MyClass1), attrOverrides)

            Dim oMyClass As New MyClass1()

            Dim g1 As New Graduate()
            g1.Name = "Jackie"
            g1.ID = 1
            g1.University = "Alma Mater"

            Dim g2 As New Graduate()
            g2.Name = "Megan"
            g2.ID = 2
            g2.University = "CM"

            Dim myArray As Student() =  {g1, g2}
            oMyClass.Students = myArray

            mySerializer.Serialize(myStreamWriter, oMyClass)
            myStreamWriter.Close()
        End Sub 'WriteOverriddenAttributes


        Private Sub ReadOverriddenAttributes(filename As String)
            ' The majority of the code here is the same as that in the
            ' WriteOverriddenAttributes method. Because the XML being read
            ' doesn't conform to the schema defined by the DLL, the
            ' XMLAttributesOverrides must be used to create an
            ' XmlSerializer instance to read the XML document.

            Dim attrOverrides As New XmlAttributeOverrides()
            Dim attrs As New XmlAttributes()
            Dim attr As New XmlElementAttribute("Alumni", GetType(Graduate))
            attrs.XmlElements.Add(attr)
            attrOverrides.Add(GetType(HighSchool.MyClass1), "Students", attrs)

            Dim readSerializer As New XmlSerializer(GetType(HighSchool.MyClass1), attrOverrides)

            ' To read the file, a FileStream object is required. 
            Dim fs As New FileStream(filename, FileMode.Open)

            Dim oMyClass As MyClass1

            oMyClass = CType(readSerializer.Deserialize(fs), MyClass1)

            ' Here is the difference between reading and writing an
            ' XML document: You must declare an object of the derived
            ' type (Graduate) and cast the Student instance to it.
            Dim g As Graduate

            Dim grad As Graduate
            For Each grad In  oMyClass.Students
                g = CType(grad, Graduate)
                Console.Write((g.Name & ControlChars.Tab))
                Console.Write((g.ID.ToString & ControlChars.Tab))
                Console.Write((g.University & ControlChars.Cr))
            Next grad
        End Sub 'ReadOverriddenAttributes
    End Class 'Run
End Namespace 'College

// Beginning of HighSchool.dll
namespace HighSchool
{
   public class Student
   {
      public string Name;
      public int ID;
   }

   public class MyClass
   {
      public Student[] Students;
   }
}

namespace College
   {
   using System;
   using System.IO;
   using System.Xml;
   using System.Xml.Serialization; 
   using HighSchool;

    public class Graduate:HighSchool.Student
    {
       public Graduate(){}
       // Add a new field named University.
       public string University;
    }


   public class Run
   {
      public static void Main()
      {
         Run test = new Run();
         test.WriteOverriddenAttributes("College.xml");
         test.ReadOverriddenAttributes("College.xml");
      }

      private void WriteOverriddenAttributes(string filename)
      {
         // Writing the file requires a TextWriter.
         TextWriter myStreamWriter = new StreamWriter(filename);
         // Create an XMLAttributeOverrides class.
         XmlAttributeOverrides attrOverrides = 
         new XmlAttributeOverrides();
         // Create the XmlAttributes class.
         XmlAttributes attrs = new XmlAttributes();

         /* Override the Student class. "Alumni" is the name
         of the overriding element in the XML output. */
         XmlElementAttribute attr = 
         new XmlElementAttribute("Alumni", typeof(Graduate));

         /* Add the XmlElementAttribute to the collection of
         elements in the XmlAttributes object. */
         attrs.XmlElements.Add(attr);

         /* Add the XmlAttributes to the XmlAttributeOverrides. 
         "Students" is the name being overridden. */
         attrOverrides.Add(typeof(HighSchool.MyClass), 
         "Students", attrs);

         // Create the XmlSerializer. 
         XmlSerializer mySerializer = new XmlSerializer
         (typeof(HighSchool.MyClass), attrOverrides);

         MyClass myClass = new MyClass();

         Graduate g1 = new Graduate();
         g1.Name = "Jackie";
         g1.ID = 1;
         g1.University = "Alma Mater";

         Graduate g2 = new Graduate();
         g2.Name = "Megan";
         g2.ID = 2;
         g2.University = "CM";

         Student[] myArray = {g1,g2};
         myClass.Students = myArray;

         mySerializer.Serialize(myStreamWriter, myClass);
         myStreamWriter.Close();
      }

      private void ReadOverriddenAttributes(string filename)
      {
         /* The majority of the code here is the same as that in the
         WriteOverriddenAttributes method. Because the XML being read
         doesn't conform to the schema defined by the DLL, the
         XMLAttributesOverrides must be used to create an 
         XmlSerializer instance to read the XML document.*/

         XmlAttributeOverrides attrOverrides = new 
         XmlAttributeOverrides();
         XmlAttributes attrs = new XmlAttributes();
         XmlElementAttribute attr = 
         new XmlElementAttribute("Alumni", typeof(Graduate));
         attrs.XmlElements.Add(attr);
         attrOverrides.Add(typeof(HighSchool.MyClass), 
         "Students", attrs);

         XmlSerializer readSerializer = new XmlSerializer
         (typeof(HighSchool.MyClass), attrOverrides);

         // To read the file, a FileStream object is required. 
         FileStream fs = new FileStream(filename, FileMode.Open);

         MyClass myClass;

         myClass = (MyClass) readSerializer.Deserialize(fs);

         /* Here is the difference between reading and writing an 
         XML document: You must declare an object of the derived 
         type (Graduate) and cast the Student instance to it.*/
         Graduate g;

         foreach(Graduate grad in myClass.Students)
         {
            g = (Graduate) grad;
            Console.Write(g.Name + "\t");
            Console.Write(g.ID + "\t");
            Console.Write(g.University + "\n");
         }
      }
   }
}

// Beginning of HighSchool.dll
#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Xml::Serialization;

namespace HighSchool
{
   public ref class Student
   {
   public:
      String^ Name;
      int ID;
   };

   public ref class MyClass
   {
   public:
      array<Student^>^Students;
   };
}

namespace College
{

using namespace HighSchool;
   public ref class Graduate: public HighSchool::Student
   {
   public:
      Graduate(){}

      // Add a new field named University.
      String^ University;
   };

   public ref class Run
   {
   public:
      static void main()
      {
         Run^ test = gcnew Run;
         test->WriteOverriddenAttributes( "College.xml" );
         test->ReadOverriddenAttributes( "College.xml" );
      }

   private:
      void WriteOverriddenAttributes( String^ filename )
      {
         // Writing the file requires a TextWriter.
         TextWriter^ myStreamWriter = gcnew StreamWriter( filename );

         // Create an XMLAttributeOverrides class.
         XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;

         // Create the XmlAttributes class.
         XmlAttributes^ attrs = gcnew XmlAttributes;

         /* Override the Student class. "Alumni" is the name
               of the overriding element in the XML output. */
         XmlElementAttribute^ attr = gcnew XmlElementAttribute( "Alumni",Graduate::typeid );

         /* Add the XmlElementAttribute to the collection of
               elements in the XmlAttributes object. */
         attrs->XmlElements->Add( attr );

         /* Add the XmlAttributes to the XmlAttributeOverrides. 
               "Students" is the name being overridden. */
         attrOverrides->Add( HighSchool::MyClass::typeid, "Students", attrs );

         // Create the XmlSerializer. 
         XmlSerializer^ mySerializer = gcnew XmlSerializer( HighSchool::MyClass::typeid,attrOverrides );
         MyClass ^ myClass = gcnew MyClass;
         Graduate^ g1 = gcnew Graduate;
         g1->Name = "Jackie";
         g1->ID = 1;
         g1->University = "Alma Mater";
         Graduate^ g2 = gcnew Graduate;
         g2->Name = "Megan";
         g2->ID = 2;
         g2->University = "CM";
         array<Student^>^myArray = {g1,g2};
         myClass->Students = myArray;
         mySerializer->Serialize( myStreamWriter, myClass );
         myStreamWriter->Close();
      }

      void ReadOverriddenAttributes( String^ filename )
      {
         /* The majority of the code here is the same as that in the
               WriteOverriddenAttributes method. Because the XML being read
               doesn't conform to the schema defined by the DLL, the
               XMLAttributesOverrides must be used to create an 
               XmlSerializer instance to read the XML document.*/
         XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;
         XmlAttributes^ attrs = gcnew XmlAttributes;
         XmlElementAttribute^ attr = gcnew XmlElementAttribute( "Alumni",Graduate::typeid );
         attrs->XmlElements->Add( attr );
         attrOverrides->Add( HighSchool::MyClass::typeid, "Students", attrs );
         XmlSerializer^ readSerializer = gcnew XmlSerializer( HighSchool::MyClass::typeid,attrOverrides );

         // To read the file, a FileStream object is required. 
         FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
         MyClass ^ myClass;
         myClass = dynamic_cast<MyClass^>(readSerializer->Deserialize( fs ));

         /* Here is the difference between reading and writing an 
               XML document: You must declare an object of the derived 
               type (Graduate) and cast the Student instance to it.*/
         Graduate^ g;
         System::Collections::IEnumerator^ myEnum = myClass->Students->GetEnumerator();
         while ( myEnum->MoveNext() )
         {
            Graduate^ grad = safe_cast<Graduate^>(myEnum->Current);
            g = dynamic_cast<Graduate^>(grad);
            Console::Write( "{0}\t", g->Name );
            Console::Write( "{0}\t", g->ID );
            Console::Write( "{0}\n", g->University );
         }
      }
   };
}

int main()
{
   College::Run::main();
}