FMOD.Studio.EventInstance.setParameterValueByIndex C# (CSharp) Method

        public RESULT setParameterValueByIndex(int index, float value)
        {
            return FMOD_Studio_EventInstance_SetParameterValueByIndex(rawPtr, index, value);
        }
        public RESULT triggerCue()

    public void ChangeState(State s)
    {
        if (s != _state)
        {
            _state = s;
            switch (_state)
            {
            case State.IDLE:
                _jumpInstance.stop(FMOD.Studio.STOP_MODE.IMMEDIATE);
                _WalkInstance.stop(FMOD.Studio.STOP_MODE.ALLOWFADEOUT);
                break;

            case State.JUMP:
                _WalkInstance.stop(FMOD.Studio.STOP_MODE.IMMEDIATE);
                _jumpInstance.start();
                break;

            case State.WALK:
                _WalkInstance.start();
                _WalkInstance.setParameterValueByIndex(_velocityIndex, 0.5f);
                break;

            case State.RUN:
                _WalkInstance.start();
                _WalkInstance.setParameterValueByIndex(_velocityIndex, 0.9f);
                break;

            default:
                break;
            }
        }
    }