Post­Sharp Documentation / API Reference / Post­Sharp.​Patterns.​Model Namespace / Notify­Property­Changed­Attribute Class

NotifyPropertyChangedAttribute Class

Custom attribute that, when applied on a type, implements the INotifyPropertyChanged interface for this class and all children classes.
Inheritance Hierarchy
System.Object
  System.Attribute
    PostSharp.Extensibility.MulticastAttribute
      PostSharp.Aspects.Aspect
        PostSharp.Aspects.TypeLevelAspect
          PostSharp.Aspects.InstanceLevelAspect
            PostSharp.Patterns.Model.NotifyPropertyChangedAttribute

Namespace:  PostSharp.Patterns.Model
Assembly:  PostSharp.Patterns.Model (in PostSharp.Patterns.Model.dll) Version: 5.0.38.0 (5.0.38.0)
Syntax
C#
public sealed class NotifyPropertyChangedAttribute : InstanceLevelAspect, 
	ISerializationCallback, INotifyPropertyChanged, IAdviceProvider, IAspect, IQueryInterface, 
	IDynamicInterfaceImplementation

The NotifyPropertyChangedAttribute type exposes the following members.

Properties
  NameDescription
Public propertyAspectPriority
Gets or sets the weaving priority of the aspect.
(Inherited from Aspect.)
Public propertyAttributeExclude
If true, indicates that this attribute removes all other instances of the same attribute type from the set of elements defined by the current instance.
(Inherited from MulticastAttribute.)
Public propertyAttributeInheritance
Determines whether this attribute is inherited
(Inherited from MulticastAttribute.)
Public propertyAttributePriority
Gets or sets the priority of the current attribute in case that multiple instances are defined on the same element (lower values are processed before).
(Inherited from MulticastAttribute.)
Public propertyAttributeReplace
Determines whether this attribute replaces other attributes found on the target declarations.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetAssemblies
Gets or sets the assemblies to which the current attribute apply.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetElements
Gets or sets the kind of elements to which this custom attributes applies.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetExternalMemberAttributes
Gets or sets the visibilities, scopes, virtualities, and implementation of members to which this attribute applies, when the member is external to the current module.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetExternalTypeAttributes
Gets or sets the visibilities of types to which this attribute applies, when this type is external to the current module.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetMemberAttributes
Gets or sets the visibilities, scopes, virtualities, and implementation of members to which this attribute applies.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetMembers
Gets or sets the expression specifying to which members this instance applies.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetParameterAttributes
Gets or sets the passing style (by value, out or ref) of parameters to which this attribute applies.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetParameters
Gets or sets the expression specifying to which parameters this instance applies.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetTypeAttributes
Gets or sets the visibilities of types to which this attribute applies.
(Inherited from MulticastAttribute.)
Public propertyAttributeTargetTypes
Gets or sets the expression specifying to which types this instance applies.
(Inherited from MulticastAttribute.)
Public propertyInstance
Gets the object to which the current aspect has been applied.
(Inherited from InstanceLevelAspect.)
Public propertyPreventFalsePositives
Determines whether the aspect should do additional efforts to prevent the PropertyChanged event from being raised when the value itself did not change. The default value of this property is false, which means that the aspect will raise the PropertyChanged event whenever any dependency of the property has changed, whether the property value has eventually changed or not. Setting this property to true consumes more memory and processing power because the aspect will need to evaluate the properties and store their value.
Methods
  NameDescription
Public methodCompileTimeInitialize
Method invoked at build time to initialize the instance fields of the current aspect. This method is invoked before any other build-time method.
(Overrides TypeLevelAspect.CompileTimeInitialize(Type, AspectInfo).)
Public methodCompileTimeValidate(Object)
Method invoked at build time to ensure that the aspect has been applied to the right target.
(Inherited from Aspect.)
Public methodCompileTimeValidate(Object)
Method invoked at build time to ensure that the aspect has been applied to the right target.
(Inherited from TypeLevelAspect.)
Public methodCompileTimeValidate(Type)
Method invoked at build time to ensure that the aspect has been applied to the right target.
(Overrides TypeLevelAspect.CompileTimeValidate(Type).)
Public methodCreateInstance
Creates a new instance of the aspect based on the current instance, serving as a prototype.
(Overrides InstanceLevelAspect.CreateInstance(AdviceArgs).)
Public methodGetAspectConfiguration
Method invoked at build tome to get the imperative configuration of the current Aspect.
(Inherited from Aspect.)
Public methodOnCloned
Method called after the an object enhanced by the current aspect has been cloned using MemberwiseClone(). The this parameter refers to the new aspect instance in the cloned object.
(Overrides InstanceLevelAspect.OnCloned(ICloneAwareAspect).)
Public methodOnFieldSet<T>
Public methodOnPropertyGet<T>
Extension Methods
  NameDescription
Public Extension MethodQueryInterface<T>
Gets the implementation of a specified interface for the specified object.
(Defined by QueryInterfaceExtensions.)
Remarks

The aspect analyzes dependencies between property getters and fields. The aspect understands indirect dependencies. For instance, a property getter may depend on several other methods or property getters, which in turn can depend on other methods or fields. The algorithm is not able to analyze calls to virtual methods or delegates (because of prohibitive computational cost), and will only try to analyze methods in the current class.

The aspect will emit a build-time error if it is not able to understand the code of the target class. In this case, you can exclude the property from automatic change notification by applying the IgnoreAutoChangeNotificationAttribute custom attribute to the problematic property, or SafeForDependencyAnalysisAttribute to ignore the warnings of the dependency analysis engine. You will then need to specify dependencies explicitly using the Depends class. You can also mark a helper method with the PureAttribute to make it safe from use in a property getter. For instance, the string.Format method is pure.

By default, the NotifyPropertyChangedAttribute aspect holds strong references to the client delegates. This behavior can cause memory leaks if client delegates are not properly removed before client objects are disposed. To cause the aspect to store weak references, pass the true value to the holdWeakReference parameter of #ctor(Boolean, Boolean) constructor.

Target classes can customize the NotifyPropertyChangedAttribute aspect by implementing the OnPropertyChanged(string) method manually. If this method is implemented, it must be protected or public.

By default, the NotifyPropertyChangedAttribute aspect does not call property getters by itself in order to avoid unexpected side-effects. However, this means that there are false positive notifications of property change. To allow aspect to use arbitrary calls to property getters to suppress false positives, pass the true value to the preventFalsePositives parameter of #ctor(Boolean, Boolean) constructor.

See Also