SoapAttributes.SoapDefaultValue Eigenschaft

Definition

Namespace:

System.Xml.Serialization

Assembly:

System.Xml.XmlSerializer.dll

Assembly:

System.Xml.dll

Assembly:

netstandard.dll

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

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

public object? SoapDefaultValue { get; set; }

public object SoapDefaultValue { get; set; }

member this.SoapDefaultValue : obj with get, set

Public Property SoapDefaultValue As Object

Eigenschaftswert

Object

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

Beispiele

Im folgenden Beispiel wird eine Klasse mit dem Namen eines Felds namens Group GroupNameserialisiert. Der Standardwert wird mit dem DefaultValueAttribute Wert ".NET" festgelegt. Wenn Sie das Feld nicht festlegen oder auf ".NET" festlegen, wird der Wert nicht serialisiert (da der Standardwert bereits bekannt ist). Das Beispiel überschreibt auch den Standardwert in der Methode, die von der CreateOverrideSerializer SerializeOverride Methode aufgerufen wird. Das Beispiel ruft sowohl Methoden SerializeOriginal als auch , und SerializeOverridelegt denselben Wert (".NET") für das GroupName Feld fest. Aufgrund der Außerkraftsetzung wird der Wert nur beim Aufrufen der SerializeOverride Methode serialisiert.

#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" );
}

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;
   }
}

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

Hinweise

Der Standardwert eines Members kann festgelegt werden, indem ein DefaultValueAttribute Attribut auf das Element angewendet wird. Wenn das Element als codierte SOAP-Nachricht serialisiert wird, können Sie den Standardwert ändern, indem Sie eine neue DefaultValueAttributeEigenschaft erstellen, die Value Eigenschaft festlegen und die SoapDefaultValue Eigenschaft auf das Objekt festlegen. Fügen Sie dies SoapAttributes zu einem SoapAttributeOverrides. Weitere Details finden Sie in der SoapAttributeOverrides Klassenübersicht.

Siehe auch

• XmlAttributes
• Attribute zur Steuerung der Serialisierung von codiertem SOAP
• Vorgehensweise: Serialisieren eines Objekts als einen durch SOAP codierten XML-Stream