vuex安装失败解决

1、报错信息：

npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! While resolving: vue-base-rooter@0.1.0
npm ERR! Found: vue@2.6.14
npm ERR! node_modules/vue
npm ERR! vue@"^2.6.11" from the root project
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer vue@"^3.0.2" from vuex@4.0.2
npm ERR! node_modules/vuex
npm ERR!
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
npm ERR!
npm ERR! See C:\Users\Mae\AppData\Local\npm-cache\eresolve-report.txt for a full report.

npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\Mae\AppData\Local\npm-cache_logs\2022-02-13T13_20_52_363Z-debug.log

2、解决方案

npm install vuex@3.6.2 -S

然后查看package.json文件

有vuex版本说明安装成功

使用小案例：定义一个加减的按钮

 代码如下：

//引入mapstate读取数据
    import {mapState} from 'vuex'
//通过computed计算属性 解构得出数据
   computed:{
     ...mapState(['count'])
      },
   methods:{
       add(){
        this.$store.dispatch('add')
       },
    reduce(){
        this.$store.dispatch('reduce')
       }
    }

在actions中上下文解构出{commit}    actions可以处理异步  

//我们在store中index.js文件中配置相应处理
  const actions={
    //此处不能直接修改mapstate
      add({commit}){
        commit("ADD");
    },
      reduce({commit}){
        commit("REDUCE");
    },
  };
 
  const mutations={
      ADD(state){
        state.count++;
    },
      REDUCE(state){
        state.count--;
      }
  };
  const state={
     count:1
  };

写到这里就可以实现按钮加减count数据的操作了   

总结