为处于Redux状态的对象中的每个项目更新单个值

// 定义action类型
const UPDATE_VALUE = "UPDATE_VALUE";

// 创建action的函数
const updateValue = (item, value) => {
  return {
    type: UPDATE_VALUE,
    payload: {
      item,
      value
    }
  };
};

// 创建reducer来处理action并更新状态
const initialState = {
  project1: {
    value: 0
  },
  project2: {
    value: 0
  }
};

const reducer = (state = initialState, action) => {
  switch (action.type) {
    case UPDATE_VALUE:
      return {
        ...state,
        [action.payload.item]: {
          ...state[action.payload.item],
          value: action.payload.value
        }
      };
    default:
      return state;
  }
};

// 创建store并将reducer传递给它
const store = Redux.createStore(reducer);

// 更新状态的示例操作
store.dispatch(updateValue("project1", 10));
store.dispatch(updateValue("project2", 20));