Class IntroduceFieldAdviceInstance

Represents a request for a field to exist in or to be introduced into the target type of the aspect. The field is introduced into the target type, or the introduction is skipped when the target type already has a compatible field, as specified by WhenCompatibleFieldExists and WhenIncompatibleMemberExists.

Inheritance

object

AdviceInstance

IntroduceFieldAdviceInstance

Namespace: PostSharp.Aspects.Advices

Assembly: PostSharp.dll

Syntax

Full screen

public sealed class IntroduceFieldAdviceInstance : AdviceInstance

Remarks

An aspect returns an IntroduceFieldAdviceInstance from ProvideAdvices(object), so that the type, the name and the number of the fields can depend on the target. The target type is the type to which the aspect is applied, or the declaring type of the member to which it is applied. Any aspect can request fields, including a statically scoped aspect, which then keeps per-object state in the target object.

The advices of the aspect instance that made the request receive the field through an advice parameter annotated with ImportMemberAttribute. With a Name, the parameter imports the field by this name, whatever the real name of the field, and the requested name wins over a member of the target type that has the same name. Without a name, the parameter imports the field by its type, and the fields requested by the aspect instance win over the other members of the target type. The requested name is visible only to the aspect instance that made the request.

The request does not initialize the field: a new field has the default value of its type when the object is created.

When several aspects request a field that can resolve to the same field, they must be ordered by aspect dependencies, because the result depends on the order: the request declares the effect MemberIntroduction, and the effect returned by GetMemberIntroductionEffect(string) for its name, or for its type when it has no name. Equivalent requests that use an existing field, such as the requests of one aspect applied to several members, share the field whatever their order and need no dependency.

Constructors

Name	Description
IntroduceFieldAdviceInstance(Type)	Initializes a new instance of the IntroduceFieldAdviceInstance class.

Properties

Name	Description
CustomAttributes	Gets the custom attributes added to the introduced field, as ObjectConstruction objects. They are not added to an existing field to which the request resolves.
FieldType	Gets the type of the field.
IsReadOnly	Gets or sets a value indicating whether the introduced field is read-only (`initonly`): only the constructors of the target type assign it. An advice imports a read-only field by value or as `in`, but not as `ref` or `out`. The default value is `false`.
IsSerialized	Gets or sets a value indicating whether the field is serialized with the object. The default value is `true`. When it is `false`, the introduced field is marked `NotSerialized`, which a serializer such as `BinaryFormatter` skips.
IsStatic	Gets or sets a value indicating whether the field is static. A static field of a generic type exists once per closed generic type.
MasterAspectMember	Gets the main field or method of the aspect class that the current AdviceInstance relates to.
Name	Gets or sets the requested name of the field, or `null`.
Visibility	Gets or sets the visibility of the introduced field. The default value is Private.
WhenCompatibleFieldExists	Gets or sets the action taken when the target type already has a field that is compatible with the request: the field that has the requested name, or, without a name, a field of the type of the request. The default value is Fail.
WhenIncompatibleMemberExists	Gets or sets the action taken when a member of the target type has the requested name but is not a compatible field. It applies only to a request with a Name. The default value is Fail.