SoapAttributes.SoapDefaultValue-Eigenschaft

Ruft den Standardwert eines XML-Elements oder -Attributs ab oder legt diesen fest.

Namespace: System.Xml.Serialization
Assembly: System.Xml (in system.xml.dll)

Syntax

'Declaration
Public Property SoapDefaultValue As Object
'Usage
Dim instance As SoapAttributes
Dim value As Object

value = instance.SoapDefaultValue

instance.SoapDefaultValue = value

public Object SoapDefaultValue { get; set; }

public:
property Object^ SoapDefaultValue {
    Object^ get ();
    void set (Object^ value);
}

/** @property */
public Object get_SoapDefaultValue ()

/** @property */
public void set_SoapDefaultValue (Object value)

public function get SoapDefaultValue () : Object

public function set SoapDefaultValue (value : Object)

Eigenschaftenwert

Ein Objekt, das den Standardwert eines XML-Elements oder -Attributs darstellt.

Hinweise

Der Standardwert eines Members kann festgelegt werden, indem dem Member ein DefaultValueAttribute-Attribut zugewiesen wird. Wenn der Member als codierte SOAP-Meldung serialisiert wird, können Sie den Standardwert ändern, indem Sie ein neues DefaultValueAttribute erstellen, die Value-Eigenschaft festlegen und die SoapDefaultValue-Eigenschaft auf das Objekt festlegen. Fügen Sie einem SoapAttributeOverrides das SoapAttributes hinzu. Weitere Informationen finden Sie in der Übersicht über die SoapAttributeOverrides-Klasse.

Beispiel

Im folgenden Beispiel wird die Klasse Group serialisiert, die das Feld GroupName enthält. Der Standardwert wird mit DefaultValueAttribute auf ".NET" festgelegt. Wenn das Feld nicht festgelegt oder auf ".NET" festgelegt wird, wird der Wert nicht serialisiert (weil der Standardwert schon bekannt ist). Im Beispiel wird außerdem der Standardwert in der CreateOverrideSerializer-Methode überschrieben, die durch die SerializeOverride-Methode aufgerufen wird. Im Beispiel wird sowohl die Methode SerializeOriginal als auch die Methode SerializeOverride aufgerufen und derselbe Wert (".NET") für das GroupName-Feld festgelegt. Aufgrund des Überschreibens wird der Wert nur serialisiert, wenn die SerializeOverride-Methode aufgerufen wird.

Imports System
Imports System.IO
Imports System.Xml
Imports System.Xml.Serialization
Imports System.Xml.Schema
Imports System.ComponentModel

Public Class Group
   ' The default is set to .NET.
   <DefaultValue(".NET")> _
   Public GroupName As String
End Class
 
Public Class Run

   Public Shared Sub Main()
   
      Dim test As Run = new Run()
      test.SerializeOriginal("SoapOriginal.xml")
      test.SerializeOverride _
      ("mySoapAttributeOverridesideAttributes.xml")
      test.DeserializeOriginal("SoapOriginal.xml")
      test.DeserializeOverride _
      ("mySoapAttributeOverridesideAttributes.xml")
   End Sub
   
   public Sub SerializeOriginal(filename As String)
       ' Create an instance of the XmlSerializer class.
      Dim mySerializer As XmlSerializer =  _
      new XmlSerializer(GetType(Group))

      ' Writing the file requires a TextWriter.
      Dim writer As TextWriter = new StreamWriter(filename)

      ' Create an instance of the class that will be serialized.
      Dim myGroup As Group = new Group()

      ' Setting the GroupName to '.NET' is like not setting it at all
      ' because it is the default value. So no value will be 
      ' serialized, and on deserialization it will appear as a blank.
      myGroup.GroupName = ".NET"

      ' Serialize the class, and close the TextWriter.
      mySerializer.Serialize(writer, myGroup)
      writer.Close()
   End Sub

   Public Sub SerializeOverride(filename As String)
   
      ' Create an instance of the XmlSerializer class
      ' that overrides the serialization.
      Dim overRideSerializer As XmlSerializer = CreateOverrideSerializer()

      ' Writing the file requires a TextWriter.
      Dim writer As TextWriter = new StreamWriter(filename)

      ' Create an instance of the class that will be serialized.
      Dim myGroup As Group = new Group()

      ' The override specifies that the default value is now 
      ' 'Team1'. So setting the GroupName to '.NET' means
      ' the value will be serialized.
      myGroup.GroupName = ".NET"
      ' Serialize the class, and close the TextWriter.
      overRideSerializer.Serialize(writer, myGroup)
       writer.Close()

   End Sub


   Public Sub DeserializeOriginal(filename As String)
   
      ' Create an instance of the XmlSerializer class.
      Dim mySerializer As XmlSerializer = new XmlSerializer(GetType(Group))
      ' Reading the file requires a TextReader.
      Dim reader As TextReader = new StreamReader(filename)

      ' Deserialize and cast the object.
      Dim myGroup As Group = CType(mySerializer.Deserialize(reader), Group)

      Console.WriteLine(myGroup.GroupName)
      Console.WriteLine()
   End Sub

   Public Sub DeserializeOverride(filename As String)
   
      ' Create an instance of the XmlSerializer class.
      Dim overRideSerializer As XmlSerializer = CreateOverrideSerializer()
      ' Reading the file requires a TextReader.
      Dim reader As TextReader = new StreamReader(filename)

      ' Deserialize and cast the object.
      Dim myGroup As Group = CType(overRideSerializer.Deserialize(reader), Group)

      Console.WriteLine(myGroup.GroupName)

   End Sub

   Private Function CreateOverrideSerializer() As XmlSerializer 
   
      Dim mySoapAttributeOverrides As SoapAttributeOverrides  = _
      New SoapAttributeOverrides()
      Dim soapAtts As SoapAttributes = New SoapAttributes()
      ' Create a new DefaultValueAttribute object for the GroupName
      ' property.
      Dim newDefault As DefaultValueAttribute = _
      new DefaultValueAttribute("Team1")
      soapAtts.SoapDefaultValue = newDefault

     mySoapAttributeOverrides.Add(GetType(Group), "GroupName", _
     soapAtts)
      
      ' Create an XmlTypeMapping that is used to create an instance 
      ' of the XmlSerializer. Then return the XmlSerializer object.
      Dim myMapping As XmlTypeMapping = _
      (New SoapReflectionImporter( _
      mySoapAttributeOverrides)).ImportTypeMapping(GetType(Group))
    
      Dim ser As XmlSerializer = new XmlSerializer(myMapping)
      return ser
   End Function
End Class

using System;
using System.IO;
using System.Xml;
using System.Xml.Serialization;
using System.Xml.Schema;
using System.ComponentModel;

public class Group
{
   // The default is set to .NET.
   [DefaultValue(".NET")]
   public string GroupName;
}
 
public class Run
{
   public static void Main()
   {
      Run test = new Run();
      test.SerializeOriginal("SoapOriginal.xml");
      test.SerializeOverride("mySoapAttributeOverridesideAttributes.xml");
      test.DeserializeOriginal("SoapOriginal.xml");
      test.DeserializeOverride("mySoapAttributeOverridesideAttributes.xml");
   }
   public void SerializeOriginal(string filename)
   {
      // Create an instance of the XmlSerializer class.
      XmlSerializer mySerializer =  
      new XmlSerializer(typeof(Group));

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

      // Create an instance of the class that will be serialized.
      Group myGroup = new Group();

      // Setting the GroupName to '.NET' is like not setting it at all
      // because it is the default value. So no value will be 
      // serialized, and on deserialization it will appear as a blank.
      myGroup.GroupName = ".NET";

      // Serialize the class, and close the TextWriter.
      mySerializer.Serialize(writer, myGroup);
      writer.Close();
   }

   public void SerializeOverride(string filename)
   {
      // Create an instance of the XmlSerializer class
      // that overrides the serialization.
      XmlSerializer overRideSerializer = CreateOverrideSerializer();

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

      // Create an instance of the class that will be serialized.
      Group myGroup = new Group();

      // The override specifies that the default value is now 
      // 'Team1'. So setting the GroupName to '.NET' means
      // the value will be serialized.
      myGroup.GroupName = ".NET";
      // Serialize the class, and close the TextWriter.
      overRideSerializer.Serialize(writer, myGroup);
       writer.Close();

   }


   public void DeserializeOriginal(string filename)
   {
      // Create an instance of the XmlSerializer class.
      XmlSerializer mySerializer= new XmlSerializer(typeof(Group));
      // Reading the file requires a TextReader.
      TextReader reader = new StreamReader(filename);

      // Deserialize and cast the object.
      Group myGroup; 
      myGroup = (Group) mySerializer.Deserialize(reader);

      Console.WriteLine(myGroup.GroupName);
      Console.WriteLine();
   }

   public void DeserializeOverride(string filename)
   {
      // Create an instance of the XmlSerializer class.
      XmlSerializer overRideSerializer = CreateOverrideSerializer();
      // Reading the file requires a TextReader.
      TextReader reader = new StreamReader(filename);

      // Deserialize and cast the object.
      Group myGroup; 
      myGroup = (Group) overRideSerializer.Deserialize(reader);

      Console.WriteLine(myGroup.GroupName);

   }

   private XmlSerializer CreateOverrideSerializer()
   {
      SoapAttributeOverrides mySoapAttributeOverrides = 
      new SoapAttributeOverrides();
      SoapAttributes soapAtts = new SoapAttributes();
      // Create a new DefaultValueAttribute object for the GroupName
      // property.
      DefaultValueAttribute newDefault = 
      new DefaultValueAttribute("Team1");
      soapAtts.SoapDefaultValue = newDefault;

      mySoapAttributeOverrides.Add(typeof(Group), "GroupName", 
      soapAtts);
      
      // Create an XmlTypeMapping that is used to create an instance 
      // of the XmlSerializer. Then return the XmlSerializer object.
      XmlTypeMapping myMapping = (new SoapReflectionImporter(
      mySoapAttributeOverrides)).ImportTypeMapping(typeof(Group));
    
      XmlSerializer ser = new XmlSerializer(myMapping);
      return ser;
   }

}

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

using namespace System;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Xml::Serialization;
using namespace System::Xml::Schema;
using namespace System::ComponentModel;
public ref class Group
{
public:

   // The default is set to .NET.

   [DefaultValue(".NET")]
   String^ GroupName;
};

public ref class Run
{
public:
   void SerializeOriginal( String^ filename )
   {
      // Create an instance of the XmlSerializer class.
      XmlSerializer^ mySerializer = gcnew XmlSerializer( Group::typeid );

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

      // Create an instance of the class that will be serialized.
      Group^ myGroup = gcnew Group;

      // Setting the GroupName to '.NET' is like not setting it at all
      // because it is the default value. So no value will be 
      // serialized, and on deserialization it will appear as a blank.
      myGroup->GroupName = ".NET";

      // Serialize the class, and close the TextWriter.
      mySerializer->Serialize( writer, myGroup );
      writer->Close();
   }

   void SerializeOverride( String^ filename )
   {
      // Create an instance of the XmlSerializer class
      // that overrides the serialization.
      XmlSerializer^ overRideSerializer = CreateOverrideSerializer();

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

      // Create an instance of the class that will be serialized.
      Group^ myGroup = gcnew Group;

      // The  specifies that the default value is now 
      // 'Team1'. So setting the GroupName to '.NET' means
      // the value will be serialized.
      myGroup->GroupName = ".NET";

      // Serialize the class, and close the TextWriter.
      overRideSerializer->Serialize( writer, myGroup );
      writer->Close();
   }

   void DeserializeOriginal( String^ filename )
   {
      // Create an instance of the XmlSerializer class.
      XmlSerializer^ mySerializer = gcnew XmlSerializer( Group::typeid );

      // Reading the file requires a TextReader.
      TextReader^ reader = gcnew StreamReader( filename );

      // Deserialize and cast the Object*.
      Group^ myGroup;
      myGroup = safe_cast<Group^>(mySerializer->Deserialize( reader ));
      Console::WriteLine( myGroup->GroupName );
      Console::WriteLine();
   }

   void DeserializeOverride( String^ filename )
   {
      // Create an instance of the XmlSerializer class.
      XmlSerializer^ overRideSerializer = CreateOverrideSerializer();

      // Reading the file requires a TextReader.
      TextReader^ reader = gcnew StreamReader( filename );

      // Deserialize and cast the Object*.
      Group^ myGroup;
      myGroup = safe_cast<Group^>(overRideSerializer->Deserialize( reader ));
      Console::WriteLine( myGroup->GroupName );
   }

private:
   XmlSerializer^ CreateOverrideSerializer()
   {
      SoapAttributeOverrides^ mySoapAttributeOverrides = gcnew SoapAttributeOverrides;
      SoapAttributes^ soapAtts = gcnew SoapAttributes;

      // Create a new DefaultValueAttribute Object* for the GroupName
      // property.
      DefaultValueAttribute^ newDefault = gcnew DefaultValueAttribute( "Team1" );
      soapAtts->SoapDefaultValue = newDefault;
      mySoapAttributeOverrides->Add( Group::typeid, "GroupName", soapAtts );

      // Create an XmlTypeMapping that is used to create an instance 
      // of the XmlSerializer. Then return the XmlSerializer Object*.
      XmlTypeMapping^ myMapping = (gcnew SoapReflectionImporter( mySoapAttributeOverrides ))->ImportTypeMapping( Group::typeid );
      XmlSerializer^ ser = gcnew XmlSerializer( myMapping );
      return ser;
   }
};

int main()
{
   Run^ test = gcnew Run;
   test->SerializeOriginal( "SoapOriginal.xml" );
   test->SerializeOverride( "mySoapAttributeOverridesideAttributes.xml" );
   test->DeserializeOriginal( "SoapOriginal.xml" );
   test->DeserializeOverride( "mySoapAttributeOverridesideAttributes.xml" );
}

import System.*;
import System.IO.*;
import System.Xml.*;
import System.Xml.Serialization.*;
import System.Xml.Schema.*;
import System.ComponentModel.*;

public class Group
{
    // The default is set to .NET.
    /** @attribute DefaultValue(".NET")
     */
    public String groupName;
} //Group

public class Run
{
    public static void main(String[] args)
    {
        Run test = new Run();
        test.SerializeOriginal("SoapOriginal.xml");
        test.SerializeOverride("mySoapAttributeOverridesideAttributes.xml");
        test.DeserializeOriginal("SoapOriginal.xml");
        test.DeserializeOverride("mySoapAttributeOverridesideAttributes.xml");
    } //main

    public void SerializeOriginal(String fileName)
    {
        // Create an instance of the XmlSerializer class.
        XmlSerializer mySerializer = new XmlSerializer(Group.class.ToType());
        
        // Writing the file requires a TextWriter.
        TextWriter writer = new StreamWriter(fileName);
        
        // Create an instance of the class that will be serialized.
        Group myGroup = new Group();
        // Setting the groupName to '.NET' is like not setting it at all
        // because it is the default value. So no value will be 
        // serialized, and on deserialization it will appear as a blank.
        myGroup.groupName = ".NET";
        
        // Serialize the class, and close the TextWriter.
        mySerializer.Serialize(writer, myGroup);
        writer.Close();
    } //SerializeOriginal

    public void SerializeOverride(String fileName)
    {
        // Create an instance of the XmlSerializer class
        // that overrides the serialization.
        XmlSerializer overRideSerializer = CreateOverrideSerializer();
        
        // Writing the file requires a TextWriter.
        TextWriter writer = new StreamWriter(fileName);
        
        // Create an instance of the class that will be serialized.
        Group myGroup = new Group();
        // The override specifies that the default value is now 
        // 'Team1'. So setting the groupName to '.NET' means
        // the value will be serialized.
        myGroup.groupName = ".NET";
        
        // Serialize the class, and close the TextWriter.
        overRideSerializer.Serialize(writer, myGroup);
        writer.Close();
    } //SerializeOverride

    public void DeserializeOriginal(String fileName)
    {
        // Create an instance of the XmlSerializer class.
        XmlSerializer mySerializer = new XmlSerializer(Group.class.ToType());
        
        // Reading the file requires a TextReader.
        TextReader reader = new StreamReader(fileName);
        
        // Deserialize and cast the object.
        Group myGroup;
        myGroup = ((Group)mySerializer.Deserialize(reader));

        Console.WriteLine(myGroup.groupName);
        Console.WriteLine();
    } //DeserializeOriginal

    public void DeserializeOverride(String fileName)
    {
        // Create an instance of the XmlSerializer class.
        XmlSerializer overRideSerializer = CreateOverrideSerializer();
        
        // Reading the file requires a TextReader.
        TextReader reader = new StreamReader(fileName);
        
        // Deserialize and cast the object.
        Group myGroup;
        myGroup = (Group)(overRideSerializer.Deserialize(reader));

        Console.WriteLine(myGroup.groupName);
    } //DeserializeOverride

    private XmlSerializer CreateOverrideSerializer()
    {
        SoapAttributeOverrides mySoapAttributeOverrides 
            = new SoapAttributeOverrides();
        SoapAttributes soapAtts = new SoapAttributes();
        // Create a new DefaultValueAttribute object for the groupName
        // property.
        DefaultValueAttribute newDefault = new DefaultValueAttribute("Team1");
        soapAtts.set_SoapDefaultValue(newDefault);

        mySoapAttributeOverrides.Add(Group.class.ToType(), "groupName", 
            soapAtts);
        // Create an XmlTypeMapping that is used to create an instance 
        // of the XmlSerializer. Then return the XmlSerializer object.
        XmlTypeMapping myMapping = (new SoapReflectionImporter(
            mySoapAttributeOverrides)).ImportTypeMapping(Group.class.ToType());

        XmlSerializer ser = new XmlSerializer(myMapping);
        return ser;
    } //CreateOverrideSerializer
} //Run 

Plattformen

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

.NET Compact Framework

Unterstützt in: 2.0

Siehe auch

Referenz

SoapAttributes-Klasse
SoapAttributes-Member
System.Xml.Serialization-Namespace
XmlAttributes

Weitere Ressourcen

Attribute für die Steuerung der Serialisierung von codiertem SOAP
Gewusst wie: Serialisieren eines Objekts als SOAP-codierter XML-Stream