Post­Sharp Documentation / API Reference / Post­Sharp.​Patterns.​Threading Namespace / Background­Attribute Class

BackgroundAttribute Class

Custom attribute that, when applied on a method, causes the method to execute in the background. This aspect can be applied to a method with void or Task return type.
Inheritance Hierarchy
System.Object
  System.Attribute
    PostSharp.Extensibility.MulticastAttribute
      PostSharp.Aspects.Aspect
        PostSharp.Aspects.MethodLevelAspect
          PostSharp.Aspects.MethodInterceptionAspect
            PostSharp.Patterns.Threading.BackgroundAttribute

Namespace:  PostSharp.Patterns.Threading
Assembly:  PostSharp.Patterns.Threading (in PostSharp.Patterns.Threading.dll) Version: 5.0.38.0 (5.0.38.0)
Syntax
C#
public sealed class BackgroundAttribute : MethodInterceptionAspect

The BackgroundAttribute type exposes the following members.

Constructors
  NameDescription
Public methodBackgroundAttribute
Initializes a new instance of the BackgroundAttribute class
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 propertyIsLongRunning
Specifies that the method is long-running and should be executed on its own thread, if that is supported on the target platform. If false, the method will be executed in the thread pool.
Public propertyUnsupportedTargetAction
Specifies the action to take when the aspect is applied to an async method with unsupported return value type.
(Inherited from MethodInterceptionAspect.)
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.
(Inherited from MethodLevelAspect.)
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 MethodLevelAspect.)
Public methodCompileTimeValidate(MethodBase)
Method invoked at build time to ensure that the aspect has been applied to the right target.
(Overrides MethodLevelAspect.CompileTimeValidate(MethodBase).)
Public methodGetAspectConfiguration
Method invoked at build tome to get the imperative configuration of the current Aspect.
(Inherited from Aspect.)
Public methodOnInvoke
Method invoked instead of the method to which the aspect has been applied.
(Overrides MethodInterceptionAspect.OnInvoke(MethodInterceptionArgs).)
Public methodOnInvokeAsync
Method invoked instead of the method to which the aspect has been applied.
(Overrides MethodInterceptionAspect.OnInvokeAsync(MethodInterceptionArgs).)
Public methodRuntimeInitialize
Initializes the current aspect.
(Inherited from MethodLevelAspect.)
Extension Methods
  NameDescription
Public Extension MethodQueryInterface<T>
Gets the implementation of a specified interface for the specified object.
(Defined by QueryInterfaceExtensions.)
Remarks

When this aspect is applied to a method returning a Task, the aspects wraps the method call by a call to Task.Factory.StartNew, therefore executing the whole method in a background thread. Without this aspect, the target method would execute asynchronously, but in the current context, instead of in the background context.

If the IsLongRunning property is set to true, the method will be executed in a new thread. Otherwise, it will be queued into the ThreadPool.

If the target method results in an exception, the exception can be handled by subscribing to the UnhandledException event. Unhandled exceptions are rethrown, typically causing the application to crash.

See Also