XmlAttributes Kelas

Definisi

Ruang nama:

System.Xml.Serialization

Rakitan:

System.Xml.XmlSerializer.dll

Sumber:

XmlAttributes.cs

Mewakili kumpulan objek atribut yang mengontrol bagaimana XmlSerializer serialisasi dan deserialisasi objek.

public ref class XmlAttributes

public class XmlAttributes

type XmlAttributes = class

Public Class XmlAttributes

Warisan

Object

XmlAttributes

Contoh

Contoh berikut menserialisasikan instans kelas bernama Orchestra, yang berisi satu bidang bernama Instruments yang mengembalikan array Instrument objek. Kelas kedua bernama Brass mewarisi dari Instrument kelas . Contoh membuat XmlAttributes objek untuk mengambil Instrument alih bidang --memungkinkan bidang menerima Brass objek--dan menambahkan objek ke instans XmlAttributesXmlAttributeOverrides kelas.

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

using namespace System;
using namespace System::IO;
using namespace System::Xml::Serialization;
public ref class Instrument
{
public:
   String^ Name;
};

public ref class Brass: public Instrument
{
public:
   bool IsValved;
};

public ref class Orchestra
{
public:
   array<Instrument^>^Instruments;
};

void SerializeObject( String^ filename )
{
   /* Each overridden field, property, or type requires 
      an XmlAttributes object. */
   XmlAttributes^ attrs = gcnew XmlAttributes;

   /* Create an XmlElementAttribute to override the 
      field that returns Instrument objects. The overridden field
      returns Brass objects instead. */
   XmlElementAttribute^ attr = gcnew XmlElementAttribute;
   attr->ElementName = "Brass";
   attr->Type = Brass::typeid;

   // Add the element to the collection of elements.
   attrs->XmlElements->Add( attr );

   // Create the XmlAttributeOverrides object.
   XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;

   /* Add the type of the class that contains the overridden 
      member and the XmlAttributes to override it with to the 
      XmlAttributeOverrides object. */
   attrOverrides->Add( Orchestra::typeid, "Instruments", attrs );

   // Create the XmlSerializer using the XmlAttributeOverrides.
   XmlSerializer^ s = gcnew XmlSerializer( Orchestra::typeid,attrOverrides );

   // Writing the file requires a TextWriter.
   TextWriter^ writer = gcnew StreamWriter( filename );

   // Create the object that will be serialized.
   Orchestra^ band = gcnew Orchestra;

   // Create an object of the derived type.
   Brass^ i = gcnew Brass;
   i->Name = "Trumpet";
   i->IsValved = true;
   array<Instrument^>^myInstruments = {i};
   band->Instruments = myInstruments;

   // Serialize the object.
   s->Serialize( writer, band );
   writer->Close();
}

void DeserializeObject( String^ filename )
{
   XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;
   XmlAttributes^ attrs = gcnew XmlAttributes;

   // Create an XmlElementAttribute to override the Instrument.
   XmlElementAttribute^ attr = gcnew XmlElementAttribute;
   attr->ElementName = "Brass";
   attr->Type = Brass::typeid;

   // Add the element to the collection of elements.
   attrs->XmlElements->Add( attr );
   attrOverrides->Add( Orchestra::typeid, "Instruments", attrs );

   // Create the XmlSerializer using the XmlAttributeOverrides.
   XmlSerializer^ s = gcnew XmlSerializer( Orchestra::typeid,attrOverrides );
   FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
   Orchestra^ band = dynamic_cast<Orchestra^>(s->Deserialize( fs ));
   Console::WriteLine( "Brass:" );

   /* The difference between deserializing the overridden 
      XML document and serializing it is this: To read the derived 
      object values, you must declare an object of the derived type 
      (Brass), and cast the Instrument instance to it. */
   Brass^ b;
   System::Collections::IEnumerator^ myEnum = band->Instruments->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Instrument^ i = safe_cast<Instrument^>(myEnum->Current);
      b = dynamic_cast<Brass^>(i);
      Console::WriteLine( "{0}\n{1}", b->Name, b->IsValved );
   }
}

int main()
{
   SerializeObject( "Override.xml" );
   DeserializeObject( "Override.xml" );
}

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

public class Orchestra
{
   public Instrument[] Instruments;
}

public class Instrument
{
   public string Name;
}

public class Brass:Instrument
{
   public bool IsValved;
}

public class Run
{
    public static void Main()
    {
       Run test = new Run();
       test.SerializeObject("Override.xml");
       test.DeserializeObject("Override.xml");
    }

    public void SerializeObject(string filename)
    {
      /* Each overridden field, property, or type requires
      an XmlAttributes object. */
      XmlAttributes attrs = new XmlAttributes();

      /* Create an XmlElementAttribute to override the
      field that returns Instrument objects. The overridden field
      returns Brass objects instead. */
      XmlElementAttribute attr = new XmlElementAttribute();
      attr.ElementName = "Brass";
      attr.Type = typeof(Brass);

      // Add the element to the collection of elements.
      attrs.XmlElements.Add(attr);

      // Create the XmlAttributeOverrides object.
      XmlAttributeOverrides attrOverrides = new XmlAttributeOverrides();

      /* Add the type of the class that contains the overridden
      member and the XmlAttributes to override it with to the
      XmlAttributeOverrides object. */
      attrOverrides.Add(typeof(Orchestra), "Instruments", attrs);

      // Create the XmlSerializer using the XmlAttributeOverrides.
      XmlSerializer s =
      new XmlSerializer(typeof(Orchestra), attrOverrides);

      // Writing the file requires a TextWriter.
      TextWriter writer = new StreamWriter(filename);

      // Create the object that will be serialized.
      Orchestra band = new Orchestra();

      // Create an object of the derived type.
      Brass i = new Brass();
      i.Name = "Trumpet";
      i.IsValved = true;
      Instrument[] myInstruments = {i};
      band.Instruments = myInstruments;

      // Serialize the object.
      s.Serialize(writer,band);
      writer.Close();
   }

   public void DeserializeObject(string filename)
   {
      XmlAttributeOverrides attrOverrides =
         new XmlAttributeOverrides();
      XmlAttributes attrs = new XmlAttributes();

      // Create an XmlElementAttribute to override the Instrument.
      XmlElementAttribute attr = new XmlElementAttribute();
      attr.ElementName = "Brass";
      attr.Type = typeof(Brass);

      // Add the element to the collection of elements.
      attrs.XmlElements.Add(attr);

      attrOverrides.Add(typeof(Orchestra), "Instruments", attrs);

      // Create the XmlSerializer using the XmlAttributeOverrides.
      XmlSerializer s =
      new XmlSerializer(typeof(Orchestra), attrOverrides);

      FileStream fs = new FileStream(filename, FileMode.Open);
      Orchestra band = (Orchestra) s.Deserialize(fs);
      Console.WriteLine("Brass:");

      /* The difference between deserializing the overridden
      XML document and serializing it is this: To read the derived
      object values, you must declare an object of the derived type
      (Brass), and cast the Instrument instance to it. */
      Brass b;
      foreach(Instrument i in band.Instruments)
      {
         b = (Brass)i;
         Console.WriteLine(
         b.Name + "\n" +
         b.IsValved);
      }
   }
}

Imports System.IO
Imports System.Xml.Serialization

Public Class Orchestra
    Public Instruments() As Instrument
End Class

Public Class Instrument
    Public Name As String
End Class

Public Class Brass
    Inherits Instrument
    Public IsValved As Boolean
End Class


Public Class Run
    
    Public Shared Sub Main()
        Dim test As New Run()
        test.SerializeObject("Override.xml")
        test.DeserializeObject("Override.xml")
    End Sub    
    
    Public Sub SerializeObject(ByVal filename As String)
        ' Each overridden field, property, or type requires
        ' an XmlAttributes object. 
        Dim attrs As New XmlAttributes()
        
        ' Create an XmlElementAttribute to override the
        ' field that returns Instrument objects. The overridden field
        ' returns Brass objects instead. 
        Dim attr As New XmlElementAttribute()
        attr.ElementName = "Brass"
        attr.Type = GetType(Brass)
        
        ' Add the element to the collection of elements.
        attrs.XmlElements.Add(attr)
        
        ' Create the XmlAttributeOverrides object.
        Dim attrOverrides As New XmlAttributeOverrides()
        
        ' Add the type of the class that contains the overridden
        ' member and the XmlAttributes to override it with to the
        ' XmlAttributeOverrides object. 
        attrOverrides.Add(GetType(Orchestra), "Instruments", attrs)
        
        ' Create the XmlSerializer using the XmlAttributeOverrides.
        Dim s As New XmlSerializer(GetType(Orchestra), attrOverrides)
        
        ' Writing the file requires a TextWriter.
        Dim writer As New StreamWriter(filename)
        
        ' Create the object that will be serialized.
        Dim band As New Orchestra()
        
        ' Create an object of the derived type.
        Dim i As New Brass()
        i.Name = "Trumpet"
        i.IsValved = True
        Dim myInstruments() As Instrument = {i}
        band.Instruments = myInstruments
        
        ' Serialize the object.
        s.Serialize(writer, band)
        writer.Close()
    End Sub
    
    
    Public Sub DeserializeObject(ByVal filename As String)
        Dim attrOverrides As New XmlAttributeOverrides()
        Dim attrs As New XmlAttributes()
        
        ' Create an XmlElementAttribute to override the Instrument.
        Dim attr As New XmlElementAttribute()
        attr.ElementName = "Brass"
        attr.Type = GetType(Brass)
        
        ' Add the element to the collection of elements.
        attrs.XmlElements.Add(attr)
        
        attrOverrides.Add(GetType(Orchestra), "Instruments", attrs)
        
        ' Create the XmlSerializer using the XmlAttributeOverrides.
        Dim s As New XmlSerializer(GetType(Orchestra), attrOverrides)
        
        Dim fs As New FileStream(filename, FileMode.Open)
        Dim band As Orchestra = CType(s.Deserialize(fs), Orchestra)
        Console.WriteLine("Brass:")
        
        ' The difference between deserializing the overridden
        ' XML document and serializing it is this: To read the derived
        ' object values, you must declare an object of the derived type
        ' (Brass), and cast the Instrument instance to it. 
        Dim b As Brass
        Dim i As Instrument
        For Each i In  band.Instruments
            b = CType(i, Brass)
            Console.WriteLine(b.Name + ControlChars.Cr + _
                              b.IsValved.ToString())
        Next i
    End Sub
End Class

Keterangan

XmlAttributes Membuat adalah bagian dari proses yang mengambil alih cara default menserialisasikan XmlSerializer instans kelas. Misalnya, Anda ingin membuat serial objek yang dibuat dari DLL yang memiliki sumber yang tidak dapat diakses. Dengan menggunakan XmlAttributeOverrides, Anda dapat menambah atau mengontrol bagaimana objek diserialisasikan.

XmlAttributes Anggota kelas sesuai langsung dengan keluarga kelas atribut yang mengontrol serialisasi. Misalnya, XmlText properti harus diatur ke XmlTextAttribute, yang memungkinkan Anda mengambil alih serialisasi bidang atau properti dengan menginstruksikan XmlSerializer untuk membuat serialisasi nilai properti sebagai teks XML. Untuk daftar lengkap atribut yang mengontrol serialisasi, lihat XmlSerializer.

Untuk detail selengkapnya tentang menggunakan XmlAttributeOverrides dengan XmlAttributes kelas , lihat Cara: Menentukan Nama Elemen Alternatif untuk Aliran XML.

Konstruktor

XmlAttributes()	Menginisialisasi instans baru kelas XmlAttributes.
XmlAttributes(ICustomAttributeProvider)	Menginisialisasi instans XmlAttributes baru kelas dan menyesuaikan bagaimana XmlSerializer serialisasi dan deserialisasi objek.

Properti

XmlAnyAttribute	Mendapatkan atau mengatur XmlAnyAttributeAttribute untuk mengambil alih.
XmlAnyElements	Mendapatkan kumpulan XmlAnyElementAttribute objek untuk diambil alih.
XmlArray	Mendapatkan atau mengatur objek yang menentukan bagaimana XmlSerializer serialisasi bidang publik atau properti baca/tulis yang mengembalikan array.
XmlArrayItems	Mendapatkan atau mengatur kumpulan objek yang menentukan bagaimana XmlSerializer menserialisasikan item yang disisipkan ke dalam array yang dikembalikan oleh bidang publik atau properti baca/tulis.
XmlAttribute	Mendapatkan atau mengatur objek yang menentukan bagaimana XmlSerializer serialisasi bidang publik atau properti baca/tulis publik sebagai atribut XML.
XmlChoiceIdentifier	Mendapatkan atau mengatur objek yang memungkinkan Anda membedakan antara sekumpulan pilihan.
XmlDefaultValue	Mendapatkan atau mengatur nilai default elemen atau atribut XML.
XmlElements	Mendapatkan kumpulan objek yang menentukan bagaimana XmlSerializer serialisasi bidang publik atau properti baca/tulis sebagai elemen XML.
XmlEnum	Mendapatkan atau mengatur objek yang menentukan bagaimana menserialisasikan XmlSerializer anggota enumerasi.
XmlIgnore	Mendapatkan atau menetapkan nilai yang menentukan apakah menserialisasikan bidang publik atau properti baca/tulis publik atau tidak XmlSerializer .
Xmlns	Mendapatkan atau menetapkan nilai yang menentukan apakah akan menyimpan semua deklarasi namespace ketika objek yang berisi anggota yang mengembalikan XmlSerializerNamespaces objek ditimpa.
XmlRoot	Mendapatkan atau mengatur objek yang menentukan bagaimana serialisasi XmlSerializer kelas sebagai elemen akar XML.
XmlText	Mendapatkan atau mengatur objek yang menginstruksikan XmlSerializer untuk membuat serial bidang publik atau properti baca/tulis publik sebagai teks XML.
XmlType	Mendapatkan atau mengatur objek yang menentukan bagaimana XmlSerializer serialisasi kelas yang XmlTypeAttribute telah diterapkan.

Metode

Equals(Object)	Menentukan apakah objek yang ditentukan sama dengan objek saat ini. (Diperoleh dari Object)
GetHashCode()	Berfungsi sebagai fungsi hash default. (Diperoleh dari Object)
GetType()	Mendapatkan instans Type saat ini. (Diperoleh dari Object)
MemberwiseClone()	Membuat salinan dangkal dari yang saat ini Object. (Diperoleh dari Object)
ToString()	Mengembalikan string yang mewakili objek saat ini. (Diperoleh dari Object)

Lihat juga

• XmlAttributeOverrides
• XmlSerializer
• Memperkenalkan Serialisasi XML
• Cara: Menentukan Nama Elemen Alternatif untuk Aliran XML
• Mengontrol Serialisasi XML Menggunakan Atribut
• Contoh Serialisasi XML
• Alat Definisi Skema XML (Xsd.exe)