The particle effectors need to be added to a ParticleSystem. They define the behavior of the particle system and/or its particles. An effector has several properties and methods that are automatically set or called by the ParticleSystem. The members are used in the following order:

1. ParticleSystem is automatically set when the effector is added to a particle system (see property Effectors).
2. RequeryParameters is called next. RequeryParameters calls OnRequeryParameters. Derived particle effectors can override this method to get all required particle parameters from the parameter collection of the particle system (see Parameters). The particle effector can store references to these parameters. Anytime the particle parameters are modified, RequeryParameters is called again.
3. Initialize is called when the particle system is updated for the first time and anytime the particle system is reset (see Reset).
4. Every time the particle system is updated, it calls BeginUpdate(TimeSpan) of all particle effectors. BeginUpdate(TimeSpan) calls OnBeginUpdate(TimeSpan). Derived particle effectors can override this method to create particles (see AddParticles(Int32, Object)), to change uniform particle parameters or to do other work.
5. After BeginUpdate(TimeSpan) the particle system calls UpdateParticles(TimeSpan, Int32, Int32) of all particle effectors. UpdateParticles(TimeSpan, Int32, Int32) calls OnUpdateParticles(TimeSpan, Int32, Int32). Derived particle effectors can override this method to manipulate the particles.
6. When the update of a particle system ends, it calls EndUpdate(TimeSpan) of all particle effectors. EndUpdate(TimeSpan) calls OnEndUpdate(TimeSpan). Derived particle effectors can override this method to perform additional checks, a clean up, or other tasks.
7. Each time a set of new particles is created, the particle system calls InitializeParticles(Int32, Int32, Object). InitializeParticles(Int32, Int32, Object) calls OnInitializeParticles(Int32, Int32, Object). Derived particle effectors can override this method to initialize the particle parameters of newly created particles.
8. When a particle effectors is removed from a particle system, Uninitialize is called. Uninitialize calls OnUninitialize. Derived classes can override this method to clean up any held resources.

Cloning: A particle effector can be cloned. When a clone is created using Clone, a new particle effectors is returned for use in another particle system. Clone does not set the property ParticleSystem of the clone. See also remarks of derived classes.

Reference