OnExceptionAspect Class |
System.Attribute
PostSharp.Extensibility.MulticastAttribute
PostSharp.Aspects.Aspect
PostSharp.Aspects.MethodLevelAspect
PostSharp.Aspects.OnExceptionAspect
Namespace: PostSharp.Aspects
Assembly: PostSharp (in PostSharp.dll) Version: 4.3.48.0 (4.3.48.0)
[SerializableAttribute] public abstract class OnExceptionAspect : MethodLevelAspect, IOnExceptionAspect, IMethodLevelAspect, IAspect
The OnExceptionAspect type exposes the following members.
Name | Description | |
---|---|---|
OnExceptionAspect | Initializes a new instance of the OnExceptionAspect class |
Name | Description | |
---|---|---|
ApplyToStateMachine |
Determines how the aspect should behave when it is applied to an iterator or
async methods, which are compiled into state machines.
| |
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 implementation
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 visibilities of types to which this attribute applies.
(Inherited from MulticastAttribute.) | |
AttributeTargetTypes |
Gets or sets the expression specifying to which types
this instance applies.
(Inherited from MulticastAttribute.) | |
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.) |
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.) | |
GetExceptionType |
Gets the type of exception handled by this aspect.
| |
OnException |
Method executed after the body of methods to which this aspect is applied,
in case that the method resulted with an exception (i.e., in a catch block).
| |
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).) |
Name | Description | |
---|---|---|
QueryInterface<T> |
Gets the implementation of a specified interface for the specified object.
(Defined by QueryInterfaceExtensions.) |
The OnExceptionAspect aspect adds an exception handler to the method to which it is applied. It allows you to easily encapsulate exception handling policies as a custom attribute.
The most important method is OnException(MethodExecutionArgs). It is the exception handler in itself.
The current exception is available from the Exception property of the MethodExecutionArgs> object. This property is read-only. If you need to replace the current exception by another one, you should throw a new exception from the handler. If you need to ignore the exception, set the FlowBehavior property to Continue.
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 );
- Get the current exception . The current exception is available on property Exception , but from the OnException(MethodExecutionArgs) advice. You cannot replace the exception by setting this property. Throw a new exception from the aspect if you need to replace the current exception.
- Get or set the return value . The return value is available on the ReturnValue property.
- Change the method control flow . You can change the value of the FlowBehavior property to specify whether the target method should 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 on OnSuccess(MethodExecutionArgs) . Using MethodExecutionTag is the only way to share state that is both thread-safe and reentrant. All other implementations are buggy.
All classes implementing IAspect should typically be marked as serializable using the custom attribute SerializableAttribute . Fields that are only used at runtime (and unknown at compile-time) should be carefully marked with the custom attribute NonSerializedAttribute . 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 . |