作用:

 将各个小的reducer整合成一个大的reducer;

方法:

combineReducers({header: headerReducer, body: bodyReducer});

注意点:

使用时, 普通对象从redux中引入combinReducers, immutable对象从redux-immutable中引入, 如下:
1, 普通对象: import { combinReducers } from 'redux';
2, immutable对象: import { combinReducers } from 'redux-immutable';