Gets a value that indicates whether the current application domain is being unloaded or the common language runtime (CLR) is shutting down.
Assembly: mscorlib (in mscorlib.dll)
When the CLR unloads an application domain, it runs the finalizers on all objects that have a finalizer method in that application domain. When the CLR shuts down, it starts the finalizer thread on all objects that have a finalizer method. The property returns true only after the finalizer thread has been started. When the property returns true, you can determine whether an application domain is being unloaded or the CLR itself is shutting down by calling the AppDomain.IsFinalizingForUnload method. This method returns true if finalizers are called because the application domain is unloading or false if the CLR is shutting down.
The property returns false if the finalizer thread has not been started.
By using this property, you can determine whether to access static variables in your finalization code. If either an application domain or the CLR is shutting down, you cannot reliably access any object that has a finalization method and that is referenced by a static field. This is because these objects may have already been finalized.