React-hooks useReducer和useContext 封装和使用

一、react-hooks useReducer和useContext 封装和使用

• userReducer.ts 数据存储文件

/**
* userReducer.ts
* 数据封装：reducer
*/ 
type Actions = 'updateUserId' | 'updatetoken';
export interface TAction {
  type: Actions;
  data: any;
}
export interface TState{
    userId: string;
    token:string
}
    
//---------------- 

export const initialState: TState = {
    userId: '11111',
    token: '22222',
};

export const reducer: React.Reducer<TState, TAction> = (state, action) => {
    console.log("state===",state)
    switch (action.type) {
        case 'updateUserId':
            return {
                ...state,
                userId: action.data
            };
        case 'updatetoken':
            return {
                ...state,
                token: action.data
            };
        default:
            return state;
    }
}

• combineReducers.ts：reducre汇总

/**
*combineReducers.ts
*reducre汇总
*/
const combineReducers = function<T>(reducers:any){
  return function(state:any, action:any): T{
    let hasChanged:any;
    const nextState = Object.keys(reducers).reduce((result, key) => {
      result[key] = reducers[key](state[key], action);
      hasChanged = hasChanged || result[key] !== state[key];
      return result;
    }, {});
    return hasChanged ? nextState : state;
  };
}

export default combineReducers;

• index.ts

/*
*index.ts
*入口文件：reducre入口文件
**/

import {
  initialState as userInitialState,
  reducer as userReducer,
  TState as TUserlState,
  TAction as TUserAction,
} from './userReducer';

import combineReducers from './combineReducers'

export const initialState = {
    userInfo: userInitialState
};

export type TState = {
    userInfo: TUserlState
};

export const reducer = combineReducers<TState>({
    userInfo: userReducer
});


export type TAction =  | TUserAction;

export interface TContextProps{
    state: TState;
    dispatch: React.dispatch<TAction>;
}

二、用法

• store/index.ts

  import React from 'react';
  
  import {
      TContextProps
  } from '@/reducer/index'
  
  const Store = React.createContext({} as TContextProps);
  
  export default Store;
  
  

• Dome…ts

  // Dome 组件
  import React, { useContext, useEffect, useRef, useState, useReducer } from 'react';
  // 组件
  import Marquee from './components/Marquee';
  
  // 状态管理
  import { TState, TAction, reducer, initialState } from '@/reducer/index';
  import Store from './store/index';
  
  const TouchBattle = React.memo(() => {
    // 备用：store 仓库
    const [state, dispatch] = useReducer<React.Reducer<TState, TAction>>(reducer, initialState);
    const initState = true
  
    return (
      <Store.Provider value={{ state, dispatch }}>
        <div>
           {/* 调用组件 */}                   
          <Marquee></Marquee>
        </div>
      </Store.Provider>
    );
  });
  
  export default TouchBattle;
  
  

• Marquee.ts 组件（使用reducer的数据）

  import React, { useContext, useEffect, useRef, useState, useReducer } from 'react';
  import Style from './index.module.scss';
  interface Props {
    marqueeWrap: object;
    marqueeContent?: object;
    children: React.ReactNode;
  }
  
  import Store from '../../store/index';
  
  // 文字走马灯滚动：keyframes
  const Marquee = React.memo<Props>((props) => {
    const { state, dispatch } = useContext(Store);
    const handleClick = ()=>{
      dispatch({type:'updateUserId',data:'1111111'})
    }
  
    return (
      <div >
        {/* 显示reducer */}
        <span>
          {state.userInfo.userId}
        </span>
        {/* 修改reducer */}
        <button onClick={handleClick}>
          点击修改
        </button>
      </div>
    );
  });
  
  export default Marquee;
  
  

三、目录结构