XmlIgnoreAttribute Class
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XmlIgnoreAttribute Class


Instructs the Serialize method of the XmlSerializer not to serialize the public field or public read/write property value.

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


[AttributeUsageAttribute(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.ReturnValue)]
public class XmlIgnoreAttribute : Attribute


Initializes a new instance of the XmlIgnoreAttribute class.


When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)


This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Returns the hash code for this instance.(Inherited from Attribute.)


Gets the Type of the current instance.(Inherited from Object.)


When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)


When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)


Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

The XmlIgnoreAttribute belongs to a family of attributes that controls how the XmlSerializer serializes or deserializes an object. If you apply the XmlIgnoreAttribute to any member of a class, the XmlSerializer ignores the member when serializing or deserializing an instance of the class. For a complete list of similar attributes, see Attributes That Control XML Serialization.

You can override the behavior caused by the XmlIgnoreAttribute by creating an XmlAttributes object, and setting its XmlIgnore property to false. You must Add the XmlAttributes object to an instance of the XmlAttributeOverrides class. Lastly, you must use the XmlAttributeOverrides object to construct an instance of the XmlSerializer class before you call the Serialize or Deserialize methods.

The XML Schema Definition Tool (Xsd.exe) occasionally generates the XmlIgnoreAttribute when creating classes from a schema file (.xsd). This behavior occurs because value types cannot be set to null, but all XML data types can be. Therefore, the tool creates two fields when it encounters an XML type that maps to a value type: one to hold the value and another special field that takes the form of fieldnameSpecified, where the fieldname is replaced by the name of the field or property. Notice, however, that this special field is generated only when the schema specifies that the element has no minimum occurrence (minOccurs = "0") and that the element has no default value. The XmlSerializer sets and checks this special field to determine whether a value has been set for the field or property. Because the special field must not be serialized, the tool applies the XmlIgnoreAttribute to it.

For more information about using attributes, see Extending Metadata Using Attributes.


You can use the word XmlIgnore in your code instead of the longer XmlIgnoreAttribute.

The following example shows a class named Group, which contains a field named Comment. The example assigns the XmlIgnoreAttribute to the field, thereby instructing the XmlSerializer to ignore the field when serializing or deserializing an instance of the class.

public class Group
   // The XmlSerializer ignores this field.
   public string Comment;

   // The XmlSerializer serializes this field.
   public string GroupName;

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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