SoapAttributeOverrides Class

Definition

Namespace:

System.Xml.Serialization

Assemblies:

netstandard.dll, System.Xml.XmlSerializer.dll

Source:

SoapAttributeOverrides.cs

Allows you to override attributes applied to properties, fields, and classes when you use an XmlSerializer to serialize or deserialize an object as encoded SOAP.

C#

public class SoapAttributeOverrides

Inheritance

Object

SoapAttributeOverrides

Examples

The following example serializes a class named Group. The serialization of the GroupName and IgnoreThis fields and the members of the GroupType enumeration are overridden. In the CreateOverrideSerializer method, a SoapAttributeOverrides is created, and for each overridden member or enumeration, a SoapAttributes is created with the appropriate property set and added to the SoapAttributeOverrides. An XmlTypeMapping is created using the SoapAttributeOverrides, and that XmlTypeMapping is used to create the XmlSerializer that overrides the default serialization.

C#

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

public class Group
{
   [SoapAttribute (Namespace = "http://www.cpandl.com")]
   public string GroupName;

   [SoapAttribute(DataType = "base64Binary")]
   public Byte [] GroupNumber;

   [SoapAttribute(DataType = "date", AttributeName = "CreationDate")]
   public DateTime Today;
   [SoapElement(DataType = "nonNegativeInteger", ElementName = "PosInt")]
   public string PostitiveInt;
   // This is ignored when serialized unless it's overridden.
   [SoapIgnore]
   public bool IgnoreThis;

   public GroupType Grouptype;

   public Vehicle MyVehicle;

   // The SoapInclude allows the method to return a Car.
   [SoapInclude(typeof(Car))]
   public Vehicle myCar(string licNumber)
   {
      Vehicle v;
      if(licNumber == "")
         {
            v = new Car();
        v.licenseNumber = "!!!!!!";
     }
      else
     {
       v = new Car();
       v.licenseNumber = licNumber;
     }
      return v;
   }
}

// SoapInclude allows Vehicle to accept Car type.
[SoapInclude(typeof(Car))]
public abstract class Vehicle
{
   public string licenseNumber;
   public DateTime makeDate;
}

public class Car: Vehicle
{
}

public enum GroupType
{
   // These enums can be overridden.
   [SoapEnum("Small")]
   A,
   [SoapEnum("Large")]
   B
}

public class Run
{
   public static void Main()
   {
      Run test = new Run();
      test.SerializeOriginal("SoapOriginal.xml");
      test.SerializeOverride("SoapOverrides.xml");
      test.DeserializeOriginal("SoapOriginal.xml");
      test.DeserializeOverride("SoapOverrides.xml");
   }
   public void SerializeOriginal(string filename)
   {
      // Create an instance of the XmlSerializer class.
      XmlTypeMapping myMapping =
      (new SoapReflectionImporter().ImportTypeMapping(
      typeof(Group)));
      XmlSerializer mySerializer =
      new XmlSerializer(myMapping);
      Group myGroup=MakeGroup();
      // Writing the file requires a TextWriter.
      XmlTextWriter writer =
      new XmlTextWriter(filename, Encoding.UTF8);
      writer.Formatting = Formatting.Indented;
      writer.WriteStartElement("wrapper");
      // Serialize the class, and close the TextWriter.
      mySerializer.Serialize(writer, myGroup);
      writer.WriteEndElement();
      writer.Close();
   }

   public void SerializeOverride(string filename)
   {
      // Create an instance of the XmlSerializer class
      // that overrides the serialization.
      XmlSerializer overRideSerializer = CreateOverrideSerializer();
      Group myGroup=MakeGroup();
      // Writing the file requires a TextWriter.
      XmlTextWriter writer =
      new XmlTextWriter(filename, Encoding.UTF8);
      writer.Formatting = Formatting.Indented;
      writer.WriteStartElement("wrapper");
      // Serialize the class, and close the TextWriter.
      overRideSerializer.Serialize(writer, myGroup);
      writer.WriteEndElement();
      writer.Close();
   }

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

      // Set the object properties.
      myGroup.GroupName = ".NET";

      Byte [] hexByte = new Byte[2]{Convert.ToByte(100),
      Convert.ToByte(50)};
      myGroup.GroupNumber = hexByte;

      DateTime myDate = new DateTime(2002,5,2);
      myGroup.Today = myDate;
      myGroup.PostitiveInt= "10000";
      myGroup.IgnoreThis=true;
      myGroup.Grouptype= GroupType.B;
      Car thisCar =(Car)  myGroup.myCar("1234566");
      myGroup.MyVehicle=thisCar;
      return myGroup;
   }   	

   public void DeserializeOriginal(string filename)
   {
      // Create an instance of the XmlSerializer class.
      XmlTypeMapping myMapping =
      (new SoapReflectionImporter().ImportTypeMapping(
      typeof(Group)));
      XmlSerializer mySerializer =
      new XmlSerializer(myMapping);

      // Reading the file requires an  XmlTextReader.
      XmlTextReader reader=
      new XmlTextReader(filename);
      reader.ReadStartElement("wrapper");

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

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

      // Reading the file requires an  XmlTextReader.
      XmlTextReader reader=
      new XmlTextReader(filename);
      reader.ReadStartElement("wrapper");

      // Deserialize and cast the object.
      Group myGroup;
      myGroup = (Group) overRideSerializer.Deserialize(reader);
      reader.ReadEndElement();
      reader.Close();
      ReadGroup(myGroup);
   }

   private void ReadGroup(Group myGroup){
      Console.WriteLine(myGroup.GroupName);
      Console.WriteLine(myGroup.GroupNumber[0]);
      Console.WriteLine(myGroup.GroupNumber[1]);
      Console.WriteLine(myGroup.Today);
      Console.WriteLine(myGroup.PostitiveInt);
      Console.WriteLine(myGroup.IgnoreThis);
      Console.WriteLine();
   }
   private XmlSerializer CreateOverrideSerializer()
   {
      SoapAttributeOverrides mySoapAttributeOverrides =
      new SoapAttributeOverrides();
      SoapAttributes soapAtts = new SoapAttributes();

      SoapElementAttribute mySoapElement = new SoapElementAttribute();
      mySoapElement.ElementName = "xxxx";
      soapAtts.SoapElement = mySoapElement;
      mySoapAttributeOverrides.Add(typeof(Group), "PostitiveInt",
      soapAtts);

      // Override the IgnoreThis property.
      SoapIgnoreAttribute myIgnore = new SoapIgnoreAttribute();
      soapAtts = new SoapAttributes();
      soapAtts.SoapIgnore = false;
      mySoapAttributeOverrides.Add(typeof(Group), "IgnoreThis",
      soapAtts);

      // Override the GroupType enumeration.	
      soapAtts = new SoapAttributes();
      SoapEnumAttribute xSoapEnum = new SoapEnumAttribute();
      xSoapEnum.Name = "Over1000";
      soapAtts.SoapEnum = xSoapEnum;

      // Add the SoapAttributes to the
      // mySoapAttributeOverridesrides object.
      mySoapAttributeOverrides.Add(typeof(GroupType), "A",
      soapAtts);

      // Create second enumeration and add it.
      soapAtts = new SoapAttributes();
      xSoapEnum = new SoapEnumAttribute();
      xSoapEnum.Name = "ZeroTo1000";
      soapAtts.SoapEnum = xSoapEnum;
      mySoapAttributeOverrides.Add(typeof(GroupType), "B",
      soapAtts);

      // Override the Group type.
      soapAtts = new SoapAttributes();
      SoapTypeAttribute soapType = new SoapTypeAttribute();
      soapType.TypeName = "Team";
      soapAtts.SoapType = soapType;
      mySoapAttributeOverrides.Add(typeof(Group),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;
   }
}

Remarks

The SoapAttributeOverrides class enables an XmlSerializer to override the default way of serializing a set of objects. Overriding serialization in this way has two uses: first, you can control and augment the serialization of objects found in a DLL, even if you do not have access to the source; second, you can create one set of serializable classes, but serialize the objects in multiple ways. For example, instead of serializing members of a class instance as XML elements, you can serialize them as XML attributes, resulting in a more efficient document to transport.

After you create a SoapAttributeOverrides, you create an XmlTypeMapping using the ImportTypeMapping method of the SoapReflectionImporter class. Pass the resulting object as an argument to the XmlSerializer constructor. The resulting XmlSerializer uses the data contained by the SoapAttributeOverrides to override attributes that control how objects are serialized. To accomplish this, the SoapAttributeOverrides contains a collection of the object types that are overridden, as well as a SoapAttributes associated with each overridden object type. Each SoapAttributes contains an appropriate set of attribute objects that control how each field, property, or class is serialized.

The process for creating and using a SoapAttributeOverrides is as follows:

1. Create a SoapAttributes.

2. Create an attribute object that is appropriate to the object being overridden. For example, to override a field or property, create a SoapElementAttribute, using the new, derived type. You can optionally assign a new ElementName that overrides the base class's attribute name or namespace.

3. Add the attribute object to the appropriate SoapAttributes property or collection. For example, you would set the SoapElement property of the SoapAttributes object to the SoapElementAttribute and specify the member name that is being overridden.

4. Create a SoapAttributeOverrides.

5. Add the SoapAttributes to the SoapAttributeOverrides using the Add method. If the object being overridden is a SoapTypeAttribute, you need only specify the type of the overridden object. But if you are overriding a field or property, you must also specify the name of the overridden member.

6. Create an XmlTypeMapping using the ImportTypeMapping method of the SoapReflectionImporter class.

7. When constructing the XmlSerializer, pass the XmlTypeMapping to the XmlSerializer constructor.

8. Use the resulting XmlSerializer to serialize or deserialize the class objects.

Constructors

SoapAttributeOverrides()

Initializes a new instance of the SoapAttributeOverrides class.

Properties

Item[Type, String]	Gets the object associated with the specified (base class) type. The member parameter specifies the base class member that is overridden.
Item[Type]	Gets the object associated with the specified (base class) type.

Methods

Add(Type, SoapAttributes)	Adds a SoapAttributes to a collection of SoapAttributes objects. The type parameter specifies an object to be overridden by the SoapAttributes.
Add(Type, String, SoapAttributes)	Adds a SoapAttributes to the collection of SoapAttributes objects contained by the SoapAttributeOverrides. The type parameter specifies the object to be overridden by the SoapAttributes. The member parameter specifies the name of a member that is overridden.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Applies to

See also

• XmlSerializer
• Introducing XML Serialization
• How to: Serialize an Object as a SOAP-Encoded XML Stream
• Attributes That Control Encoded SOAP Serialization
• Examples of XML Serialization