public MixEffectBlock(Switcher switcher, IBMDSwitcherMixEffectBlock bmd, IMediator mediator) { _switcher = switcher; _bmd = bmd; _mediator = mediator; _transitionParameters = _bmd.GetTransitionParameters(); _bmd.AddCallback(new MixEffectBlockCallback(this, _mediator)); _transitionParameters.AddCallback(new TransitionParametersCallback(_transitionParameters, _mediator)); }