使用liveDataBus 管理liveData

/** * 这条总线的用于把任何类中的数据直接传递到activity 或fragment 上 */public class LiveDataBus {//    存放订阅者    private Map<String, MutableLiveData<Object>> bus;    private static LiveDataBus liveDataBus = new LiveDataBus();    private LiveDataBus(){ bus = new HashMap<>();    }    public static LiveDataBus getInstance(){ return liveDataBus;    }//    注册订阅者，存入（map）    public synchronized <T> MutableLiveData<T> with(String key, Class<T> type, boolean sticky){ if (bus.containsKey(key)){     if (sticky){  bus.put(key, new MutableLiveData<Object>());     }else {  bus.put(key, new NonStickyMutableLiveData<Object>());     } } return (MutableLiveData<T>) bus.get(key);    }}