XmlElementAttributes クラスとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

索引トップ用語の索引ランキング

XmlElementAttributes クラス

XmlSerializer がクラスをシリアル化する既定の方法をオーバーライドするために使用する、XmlElementAttribute オブジェクトのコレクションを表します。

名前空間: System.Xml.Serialization
アセンブリ: System.Xml (system.xml.dll 内)
構文

Visual Basic (宣言)

Public Class XmlElementAttributes
    Inherits CollectionBase

Visual Basic (使用法)

Dim instance As XmlElementAttributes

public class XmlElementAttributes : CollectionBase

C++

public ref class XmlElementAttributes : public
 CollectionBase

public class XmlElementAttributes extends CollectionBase

JScript

public class XmlElementAttributes extends
 CollectionBase

解説

XmlElementAttributes は、XmlAttributes クラスの XmlElements プロパティによって返されます。XmlAttributeOverrides クラスと XmlAttributes クラスを使用して、XmlSerializer がクラスをシリアル化する既定の方法をオーバーライドできます。

使用例

Transportation クラスをシリアル化する例を次に示します。この例には、ArrayList を返す Vehicles という名前の単一のフィールドが含まれています。この例では、最初に XmlElementAttribute クラスの 2 つのインスタンスを Vehicles フィールドに適用しており、各インスタンスは、XmlSerializer が配列に挿入できるオブジェクトの型を指定しています。次に、2 つの XmlElementAttribute オブジェクトを作成し、Vehicles プロパティに適用される属性の動作をオーバーライドします。オーバーライドする側の 2 つのオブジェクトは、XmlAttributes の XmlElementAttributes コレクションに追加されます。最後に、この XmlAttributes を XmlAttributeOverrides に追加します。これにより、XmlSerializer が、Vehicles フィールドによって返される ArrayList に新しいオブジェクト型を挿入できるようになります。

Visual Basic

Imports System
Imports System.IO
Imports System.Xml.Serialization
Imports System.Collections
Imports System.Xml


Public Class Transportation
    ' Override these two XmlElementAttributes.
    <XmlElement(GetType(Car)), _
     XmlElement(GetType(Plane))> _
    Public Vehicles As ArrayList
End Class

Public Class Car
    Public Name As String
End Class

Public Class Plane
    Public Name As String
End Class

Public Class Truck
    Public Name As String
End Class

Public Class Train
    Public Name As String
End Class

Public Class Test
    
    Public Shared Sub Main()
        Dim t As New Test()
        t.SerializeObject("OverrideElement.xml")
    End Sub
    
    
    Public Function CreateOverrider() As
 XmlSerializer
        ' Create XmlAtrributes and XmlAttributeOverrides instances.
 
        Dim attrs As New
 XmlAttributes()
        
        Dim xOver As New
 XmlAttributeOverrides()
        
        ' Create an XmlElementAttributes object to override
        ' one of the attributes applied to the Vehicles property. 
        Dim xElement1 As New
 XmlElementAttribute(GetType(Truck))
        ' Add the XmlElementAttribute to the collection.
        attrs.XmlElements.Add(xElement1)
        
        ' Create a second XmlElementAttribute and
        ' add it to the collection. 
        Dim xElement2 As New
 XmlElementAttribute(GetType(Train))
        attrs.XmlElements.Add(xElement2)
        
        ' Add the XmlAttributes to the XmlAttributeOverrides,
        ' specifying the member to override. 
        xOver.Add(GetType(Transportation), "Vehicles",
 attrs)
        
        ' Create the XmlSerializer, and return it.
        Dim xSer As New
 XmlSerializer(GetType(Transportation), xOver)
        Return xSer
    End Function
    
    
    Public Sub SerializeObject(ByVal
 filename As String)
        ' Create an XmlSerializer instance.
        Dim xSer As XmlSerializer = CreateOverrider()
        
        ' Create the object.
        Dim myTransportation As New
 Transportation()
        
        ' Create two new, overriding objects that can be
        ' inserted into the Vehicles array. 
        myTransportation.Vehicles = New ArrayList()
        Dim myTruck As New
 Truck()
        myTruck.Name = "MyTruck"
        
        Dim myTrain As New
 Train()
        myTrain.Name = "MyTrain"
        
        myTransportation.Vehicles.Add(myTruck)
        myTransportation.Vehicles.Add(myTrain)
        
        Dim writer As New
 StreamWriter(filename)
        xSer.Serialize(writer, myTransportation)
    End Sub
End Class

using System;
using System.IO;
using System.Xml.Serialization;
using System.Collections;
using System.Xml;

public class Transportation
{
   // Override these two XmlElementAttributes.
   [XmlElement(typeof(Car)),
   XmlElement(typeof(Plane))]
   public ArrayList Vehicles;
}

public class Car
{
   public string Name;
}

public class Plane
{
   public string Name;
}

public class Truck
{
   public string Name;
}

public class Train
{
   public string Name;
}

public class Test
{
   public static void Main()
   {
      Test t = new Test();
      t.SerializeObject("OverrideElement.xml");
   }

   public XmlSerializer CreateOverrider()
   {
      // Create XmlAtrributes and XmlAttributeOverrides instances. 
   
      XmlAttributes attrs = new XmlAttributes();

      XmlAttributeOverrides xOver = 
      new XmlAttributeOverrides();
      
      /* Create an XmlElementAttributes object to override 
      one of the attributes applied to the Vehicles property. */
      XmlElementAttribute xElement1 = 
      new XmlElementAttribute(typeof(Truck));
      // Add the XmlElementAttribute to the collection.
      attrs.XmlElements.Add(xElement1);

      /* Create a second XmlElementAttribute and 
      add it to the collection. */
      XmlElementAttribute xElement2 = 
      new XmlElementAttribute(typeof(Train));
      attrs.XmlElements.Add(xElement2);

      /* Add the XmlAttributes to the XmlAttributeOverrides,
      specifying the member to override. */
      xOver.Add(typeof(Transportation), "Vehicles", attrs);
      
      // Create the XmlSerializer, and return it.
      XmlSerializer xSer = new XmlSerializer
      (typeof(Transportation), xOver);
      return xSer;
   }

   public void SerializeObject(string
 filename)
   {
      // Create an XmlSerializer instance.
      XmlSerializer xSer = CreateOverrider();

      // Create the object.
      Transportation myTransportation = 
      new Transportation();

      /* Create two new, overriding objects that can be
      inserted into the Vehicles array. */
      myTransportation.Vehicles = new ArrayList();
      Truck myTruck = new Truck();
      myTruck.Name = "MyTruck";

      Train myTrain = new Train();
      myTrain.Name = "MyTrain";

      myTransportation.Vehicles.Add(myTruck);
      myTransportation.Vehicles.Add(myTrain);

      TextWriter writer = new StreamWriter(filename);
      xSer.Serialize(writer, myTransportation);
   }
}

C++

#using <System.Xml.dll>
#using <System.dll>

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

public ref class Car
{
public:
   String^ Name;
};

public ref class Plane
{
public:
   String^ Name;
};

public ref class Truck
{
public:
   String^ Name;
};

public ref class Train
{
public:
   String^ Name;
};

public ref class Transportation
{
public:

   // Override these two XmlElementAttributes.

   [XmlElement(Car::typeid),
   XmlElement(Plane::typeid)]
   ArrayList^ Vehicles;
};

XmlSerializer^ CreateOverrider()
{
   // Create XmlAtrributes and XmlAttributeOverrides instances. 
   XmlAttributes^ attrs = gcnew XmlAttributes;
   XmlAttributeOverrides^ xOver = gcnew XmlAttributeOverrides;

   /* Create an XmlElementAttributes object to override 
      one of the attributes applied to the Vehicles property. */
   XmlElementAttribute^ xElement1 = gcnew XmlElementAttribute( Truck::typeid );

   // Add the XmlElementAttribute to the collection.
   attrs->XmlElements->Add( xElement1 );

   /* Create a second XmlElementAttribute and 
      add it to the collection. */
   XmlElementAttribute^ xElement2 = gcnew XmlElementAttribute( Train::typeid );
   attrs->XmlElements->Add( xElement2 );

   /* Add the XmlAttributes to the XmlAttributeOverrides,
      specifying the member to override. */
   xOver->Add( Transportation::typeid, "Vehicles", attrs );

   // Create the XmlSerializer, and return it.
   XmlSerializer^ xSer = gcnew XmlSerializer( Transportation::typeid,xOver );
   return xSer;
}

void SerializeObject( String^ filename )
{
   // Create an XmlSerializer instance.
   XmlSerializer^ xSer = CreateOverrider();

   // Create the object.
   Transportation^ myTransportation = gcnew Transportation;

   /* Create two new, overriding objects that can be
      inserted into the Vehicles array. */
   myTransportation->Vehicles = gcnew ArrayList;
   Truck^ myTruck = gcnew Truck;
   myTruck->Name = "MyTruck";
   Train^ myTrain = gcnew Train;
   myTrain->Name = "MyTrain";
   myTransportation->Vehicles->Add( myTruck );
   myTransportation->Vehicles->Add( myTrain );
   TextWriter^ writer = gcnew StreamWriter( filename );
   xSer->Serialize( writer, myTransportation );
}

int main()
{
   SerializeObject( "OverrideElement.xml" );
}

import System.*;
import System.IO.*;
import System.Xml.Serialization.*;
import System.Collections.*;
import System.Xml.*;

public class Transportation
{
    // Override these two XmlElementAttributes.
    /** @attribute XmlElement(Car.class)
        @attribute XmlElement(Plane.class)
     */
    public ArrayList vehicles;
} //Transportation

public class Car
{
    public String name;
} //Car

public class Plane
{
    public String name;
} //Plane

public class Truck
{
    public String name;
} //Truck

public class Train
{
    public String name;
} //Train

public class Test
{
    public static void main(String[]
 args)
    {
        Test t = new Test();
        t.SerializeObject("OverrideElement.xml");
    } //main

    public XmlSerializer CreateOverrider()
    {
        // Create XmlAtrributes and XmlAttributeOverrides instances.
 
        XmlAttributes attrs = new XmlAttributes();
        XmlAttributeOverrides xOver = new XmlAttributeOverrides();

        /* Create an XmlElementAttributes object to override 
           one of the attributes applied to the Vehicles property. */
        XmlElementAttribute xElement1 =
            new XmlElementAttribute(Truck.class.ToType());

        // Add the XmlElementAttribute to the collection.
        attrs.get_XmlElements().Add(xElement1);

        /* Create a second XmlElementAttribute and 
           add it to the collection. */
        XmlElementAttribute xElement2 =
            new XmlElementAttribute(Train.class.ToType());
        attrs.get_XmlElements().Add(xElement2);

        /* Add the XmlAttributes to the XmlAttributeOverrides,
           specifying the member to override. */
        xOver.Add(Transportation.class.ToType(), "vehicles",
 attrs);

        // Create the XmlSerializer, and return it.
        XmlSerializer xSer =
            new XmlSerializer(Transportation.class.ToType(),
 xOver);
        return xSer;
    } //CreateOverrider

    public void SerializeObject(String fileName)
    {
        // Create an XmlSerializer instance.
        XmlSerializer xSer = CreateOverrider();

        // Create the object.
        Transportation myTransportation = new Transportation();

        /* Create two new, overriding objects that can be
           inserted into the Vehicles array. */
        myTransportation.vehicles = new ArrayList();
        Truck myTruck = new Truck();
        myTruck.name = "MyTruck";

        Train myTrain = new Train();
        myTrain.name = "MyTrain";

        myTransportation.vehicles.Add(myTruck);
        myTransportation.vehicles.Add(myTrain);

        TextWriter writer = new StreamWriter(fileName);
        xSer.Serialize(writer, myTransportation);
    } //SerializeObject
} //Test