OnMethodBoundaryAspect Class |
System.Attribute
PostSharp.Extensibility.MulticastAttribute
PostSharp.Aspects.Aspect
PostSharp.Aspects.MethodLevelAspect
PostSharp.Aspects.OnMethodBoundaryAspect
Namespace: PostSharp.Aspects
Assembly: PostSharp (in PostSharp.dll) Version: 2023.0.3.0 (2023.0.3.0)
[SerializableAttribute] public abstract class OnMethodBoundaryAspect : MethodLevelAspect, IOnStateMachineBoundaryAspect, IOnMethodBoundaryAspect, IMethodLevelAspect, IAspect
The OnMethodBoundaryAspect type exposes the following members.
Name | Description | |
---|---|---|
OnMethodBoundaryAspect | Initializes a new instance of the OnMethodBoundaryAspect class |
Name | Description | |
---|---|---|
AspectPriority |
Gets or sets the weaving priority of the aspect.
(Inherited from Aspect.) | |
AttributeExclude |
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.) | |
AttributeInheritance |
Determines whether this attribute is inherited
(Inherited from MulticastAttribute.) | |
AttributePriority |
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.) | |
AttributeReplace |
Determines whether this attribute replaces other attributes found on the
target declarations.
(Inherited from MulticastAttribute.) | |
AttributeTargetAssemblies |
Gets or sets the assemblies to which the current attribute apply.
(Inherited from MulticastAttribute.) | |
AttributeTargetElements |
Gets or sets the kind of elements to which this custom attributes applies.
(Inherited from MulticastAttribute.) | |
AttributeTargetExternalMemberAttributes |
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.) | |
AttributeTargetExternalTypeAttributes |
Gets or sets the visibilities of types to which this attribute applies,
when this type is external to the current module.
(Inherited from MulticastAttribute.) | |
AttributeTargetMemberAttributes |
Gets or sets the visibilities, scopes, virtualities, and other characteristics
of members to which this attribute applies.
(Inherited from MulticastAttribute.) | |
AttributeTargetMembers |
Gets or sets the expression specifying to which members
this instance applies.
(Inherited from MulticastAttribute.) | |
AttributeTargetParameterAttributes |
Gets or sets the passing style (by value, out or ref)
of parameters to which this attribute applies.
(Inherited from MulticastAttribute.) | |
AttributeTargetParameters |
Gets or sets the expression specifying to which parameters
this instance applies.
(Inherited from MulticastAttribute.) | |
AttributeTargetTypeAttributes |
Gets or sets the attributes of types to which this attribute applies. Visibility, scope (Instance or Static)
and generation are the only categories that are taken into account; attributes of other categories are ignored.
(Inherited from MulticastAttribute.) | |
AttributeTargetTypes |
Gets or sets the expression specifying to which types
this instance applies.
(Inherited from MulticastAttribute.) | |
SemanticallyAdvisedMethodKinds |
Determines which target methods will be advised semantically. This affects the behavior of the aspect when it's applied to
iterator or async methods, which are compiled into state machines.
| |
SerializerType |
Gets or sets the Type of the serializer (a type derived
from AspectSerializer) used to serialize the aspect instance
at build time and deserialize it at runtime.
(Inherited from Aspect.) | |
UnsupportedTargetAction |
Specifies the action to take when the aspect is applied to an unsupported target method.
|
Name | Description | |
---|---|---|
CompileTimeInitialize |
Method invoked at build time to initialize the instance fields of the current aspect. This method is invoked
before any other build-time method.
(Inherited from MethodLevelAspect.) | |
CompileTimeValidate(Object) |
Method invoked at build time to ensure that the aspect has been applied to the right target.
(Inherited from MethodLevelAspect.) | |
CompileTimeValidate(MethodBase) |
Method invoked at build time to ensure that the aspect has been applied to the right target.
(Inherited from MethodLevelAspect.) | |
CreateAspectConfiguration |
Method invoked at build time to create a concrete AspectConfiguration instance specifically
for the current Aspect type.
(Overrides Aspect.CreateAspectConfiguration().) | |
GetAspectConfiguration |
Method invoked at build tome to get the imperative configuration of the current Aspect.
(Inherited from Aspect.) | |
OnEntry |
Method executed before the body of methods to which this aspect is applied.
| |
OnException |
Method executed after the body of methods to which this aspect is applied,
in case that the method resulted with an exception.
| |
OnExit |
Method executed after the body of methods to which this aspect is applied,
even when the method exists with an exception (this method is invoked from
the finally block).
| |
OnResume |
Method executed when a state machine resumes execution after a yield return or
await statement.
| |
OnSuccess |
Method executed after the body of methods to which this aspect is applied,
but only when the method successfully returns (i.e. when no exception flies out
the method.).
| |
OnYield |
Method executed when a state machine yields, as the result of a yield return or
await statement.
| |
RuntimeInitialize |
Initializes the current aspect.
(Inherited from MethodLevelAspect.) | |
SetAspectConfiguration(AspectConfiguration, Object) |
Method invoked at build time to set up an AspectConfiguration object according to the current
Aspect instance and a specified target element of the current aspect.
(Inherited from MethodLevelAspect.) | |
SetAspectConfiguration(AspectConfiguration, MethodBase) |
Method invoked at build time to set up an AspectConfiguration object according to the current
Aspect instance and a specified target element of the current aspect.
(Overrides MethodLevelAspect.SetAspectConfiguration(AspectConfiguration, MethodBase).) |
The OnMethodBoundaryAspect aspect results in the target method to be wrapped into a try ... catch ... finally block. You can implement four advices: OnEntry(MethodExecutionArgs), executed at the beginning of the block; OnSuccess(MethodExecutionArgs), executed only when the method is successful (i.e. does not result in an exception); OnException(MethodExecutionArgs), invoked when the method results in an exception; and OnExit(MethodExecutionArgs), always executed after method execution (whether the method resulted in an exception or not).
Schematically, the aspect transforms the original method as follows:
int MyMethod(object arg0, int arg1) { OnEntry(); try { // Original method body. OnSuccess(); return returnValue; } catch ( Exception e ) { OnException(); } finally { OnExit(); } }
Note that this code is only schematic; actually generated instructions are more complex because they have to cope with parameter boxing and control flow modification, among others.
An object of type MethodExecutionArgs is passed to every advice of this aspect. This object allows you to:
- Get or set arguments. Input and output arguments are available on the property Arguments. You can change output (out) and by-reference (ref) arguments, but not input arguments. If you need to modify arguments passed by value, consider using a MethodInterceptionAspect (see property Arguments).
- Get the current exception. The current exception is available in the property Exception (only from the OnException(MethodExecutionArgs) advice). You can also replace the exception (see Exception for details).
- Get or set the return value. The return value is available in the ReturnValue property. You can also modify it.
- Change the method control flow. You can change the value of the FlowBehavior property to specify whether the target method should continue to execute after the execution of the current advice. This may be useful to implement a caching aspect or an exception handler.
- Share state between advices. You can use the MethodExecutionTag property to store state between the execution of different advices related to the same execution of a method. For instance, you can store a cache key in OnEntry(MethodExecutionArgs) and find it back in OnSuccess(MethodExecutionArgs). Using MethodExecutionTag is the only way to share state that is both thread-safe and reentrant.
You can apply a method boundary aspect to a method that is outside your assembly. If you do, all calls to that method are intercepted and replaced with calls to a new method, in your assembly, that calls the original method. When this happens, by-reference parameters (ref) undergo special treatment similar to what happens in MethodInterceptionAspect.
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 PostSharp is used on a platform that does not support aspect serialization (such as .NET Compact Framework, Silverlight, or Windows Phone), or when another aspect serializer is used, it is not necessary to mark the aspect class as serializable. For more information, see Aspect Serialization . |