Aspect that, when applied on a location (field or property), intercepts invocations of
the Get (OnGetValue(LocationInterceptionArgs)) and Set (OnSetValue(LocationInterceptionArgs)) semantics.
Inheritance
Implements
Namespace: PostSharp.Aspects
Assembly: PostSharp.dll
Syntax
[MulticastAttributeUsage(MulticastTargets.Field|MulticastTargets.Property, TargetMemberAttributes = MulticastAttributes.NonAbstract|MulticastAttributes.NonLiteral, AllowExternalAssemblies = false, AllowMultiple = true)]
[HasInheritedAttribute]
[AttributeUsage(AttributeTargets.Assembly|AttributeTargets.Class|AttributeTargets.Struct|AttributeTargets.Property|AttributeTargets.Field|AttributeTargets.Interface, AllowMultiple = true)]
[AspectConfigurationAttributeType(typeof(LocationInterceptionAspectConfigurationAttribute))]
[Serializer(null)]
public abstract class LocationInterceptionAspect : LocationLevelAspect, ILocationLevelAspectBuildSemantics, IAspectBuildSemantics, IValidableAnnotation, ILocationInterceptionAspect, IOnInstanceLocationInitializedAspect, ILocationLevelAspect, IAspectRemarks
This aspect can be applied to fields and properties, which are called locations because both have the semantics of a slot where a value can be stored and retrieved.
Applying the Aspect on Properties
Applying an aspect of type LocationInterceptionAspect to a property results in the accessors of this property being replaced by a call to the method OnGetValue(LocationInterceptionArgs) or OnSetValue(LocationInterceptionArgs) of the current class. The original body of the accessor is moved into a new method, which can be called by the aspect by invoking one of the methods ProceedGetValue(), ProceedSetValue(), GetCurrentValue() or SetNewValue(object), or by using the Binding object.
Applying the Aspect on Fields
Applying this aspect on a field transforms the field into a property of the same name, scope and visibility as the original field. The original field is removed. Aspect code can get or set the value of the field by calling the methods ProceedGetValue(), ProceedSetValue(), GetCurrentValue() or SetNewValue(object), or by using the Binding object.
note
Remember to use PropertyInfo instead of FieldInfo at runtime to reflect the original field. For this reason, you cannot store a FieldInfo in the aspect. Store a LocationInfo instead. Even if a LocationInfo represents a field at build time, it represents the corresponding PropertyInfo at runtime.
note
When you apply an aspect derived from LocationInterceptionAspect to a value-type field,
you should not pass the value of this field by reference, that is, as an argument to out and ref parameters in C#.
This is because PostSharp is unable to detect read and write accesses through references.
Initialization of Instance Fields and Properties
The inline initialization of instance fields and auto-implemented properties does not invoke OnSetValue(LocationInterceptionArgs). To react to the initial value of such a location, override OnInstanceLocationInitialized(LocationInitializationArgs).
note
All classes implementing IAspect should typically be marked as serializable using the SerializableAttribute or PSerializableAttribute custom attribute. Fields that are only used at runtime (and unknown at compile-time) should be carefully marked with the NonSerializedAttribute or PNonSerializedAttribute custom attribute. When another aspect serializer (such as MsilAspectSerializer) is used, it is not necessary to mark the aspect class as serializable. For more information, see Understanding Aspect Serialization.
Constructors
| Name | Description |
|---|---|
| LocationInterceptionAspect() |
Methods
| Name | Description |
|---|---|
| CreateAspectConfiguration() | Method invoked at build time to create a concrete AspectConfiguration instance specifically for the current Aspect type. |
| OnGetValue(LocationInterceptionArgs) | Method invoked instead of the |
| OnInstanceLocationInitialized(LocationInitializationArgs) | Method invoked after an initial value is set for a field or property to which the current aspect is applied. The method is invoked only for instance fields and instance auto-implemented properties, and it is invoked after their inline initialization. For static fields and properties, and for accesses from the constructor, OnSetValue(LocationInterceptionArgs) is invoked instead. |
| OnSetValue(LocationInterceptionArgs) | Method invoked instead of the |