1. // selectTotal 获取数据条数
    2. // selectAll 获取所有数据 以数组形式呈现
    3. // selectEntities 获取实体集合 以字典形式呈现
    4. // selectIds 获取id集合, 以数组形式呈现
    5. const { selectIds, selectEntities, selectAll, selectTotal } = adapter.getSelectors();
    1. export const selectTodo = createFeatureSelector<AppState, State>(todoFeatureKey)
    2. export const selectTodos = createSelector(selectTodo, selectAll)