vue实现

效果

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目录结构

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Count.vue

<template>
  <div>
    <h1>当前step值为：{{ step }}</h1>
    <h1>当前sum值为：{{ sum }}</h1>
    <select v-model="step">
      <option :value="1">1</option>
      <option :value="2">2</option>
      <option :value="3">3</option>
    </select>
    <button v-on:click="increment">+</button>
    <button v-on:click="decrement">-</button>
    <button v-on:click="incrementOdd">当sum值为偶数时使sum+step</button>
    <button v-on:click="incrementWait">延迟1秒使sum+step</button>
    <br />
    <h1>{{ msg }}</h1>
  </div>
</template>

<script>
export default {
  name: "Count",
  data() {
    return {
      step: 1,
      sum: 0,
      msg: "",
    };
  },
  methods: {
    increment() {
      this.sum += this.step;
      this.msg = "已经完成相加";
    },
    decrement() {
      this.sum -= this.step;
      this.msg = "已经完成相减";
    },
    incrementOdd() {
      if (this.sum % 2 === 0) {
        this.increment();
      } else {
        this.msg = "此时sum不是偶数";
      }
    },
    incrementWait() {
      this.msg = "一秒后完成加法";
      setTimeout(() => {
        this.increment();
      }, 1000);
    },
  },
};
</script>

App.vue

<template>
  <div id="app">
    <Count></Count>
  </div>
</template>

<script>
import Count from "./components/Count.vue";
export default {
  name: "App",
  components: {
    Count,
  },
};
</script>

main.js

import Vue from 'vue'
import App from './App.vue'

Vue.config.productionTip = false

new Vue({
  render: h => h(App),
}).$mount('#app')

index.html

<!DOCTYPE html>
<html lang="">
  <head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width,initial-scale=1.0" />
    <link rel="icon" href="<%= BASE_URL %>favicon.ico" />
    <title><%= htmlWebpackPlugin.options.title %></title>
  </head>
  <body>
    <div id="app"></div>
    <!-- built files will be auto injected -->
  </body>
</html>

vuex实现

效果

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vuex使用步骤

安装
npm i vuex@3
创建文件
在src文件夹下创建store/index.js
编写vuex基本结构
引入vue和插件vuex，创建Vuex中最为核心的Vuex.Store实例对象store并向外暴露
将store传入Vue实例对象vm中
在main.js中引入store，并在new Vue时传入store

vuex基本结构

常常是src/store/index.js文件

//引入Vue
import Vue from "vue";
// 引入Vuex插件
import Vuex from "vuex";
//使用Vuex插件
Vue.use(Vuex);

//用于响应组件中的动作
const actions = {};
// 用于操作数据
const mutations = {};
// 用于存储数据
const state = {};

//创建并暴露store
export default new Vuex.Store({
  actions,
  mutations,
  state,
});

目录结构

store/index.js文件

//引入Vue
import Vue from "vue";
// 引入Vuex插件
import Vuex from "vuex";
//使用Vuex插件
Vue.use(Vuex);
//用于响应组件中的动作
const actions = {
  add(context, value) {
    context.commit("ADD", value);
  },
  reduce(context, value) {
    context.commit("REDUCE", value);
  },
  addOdd(context, value) {
    if (state.num % 2 === 0) {
      context.commit("ADD", value);
    } else {
      state.msg = "此时sum不是偶数";
    }
  },
  addWait(context, value) {
    state.msg = "1秒后执行sum+step";
    setTimeout(() => {
      context.commit("ADD", value);
    }, 1000);
  },
};
// 用于操作数据
const mutations = {
  ADD(state, value) {
    state.sum += value;
    state.msg = "已经完成相加";
  },
  REDUCE(state, value) {
    state.sum -= value;
    state.msg = "已经完成相加";
  },
};
// 用于存储数据
const state = {
  sum: 0,
  msg: "",
};

//创建并暴露store
export default new Vuex.Store({
  actions,
  mutations,
  state,
});

CountVuex.vue

<template>
  <div id="root">
    <h1>当前step值为：{{ step }}</h1>
    <h1>当前sum值为：{{ $store.state.sum }}</h1>
    <select v-model="step">
      <option :value="1">1</option>
      <option :value="2">2</option>
      <option :value="3">3</option>
    </select>
    <button v-on:click="increment">+</button>
    <button v-on:click="decrement">-</button>
    <button v-on:click="incrementOdd">当sum值为偶数时使sum+step</button>
    <button v-on:click="incrementWait">延迟1秒使sum+step</button>
    <br />
    <h1>提示：{{ $store.state.msg }}</h1>
  </div>
</template>

<script>
export default {
  name: "CountVuex",
  data() {
    return {
      step: 1,
    };
  },
  methods: {
    increment() {
      this.$store.dispatch("add", this.step);
    },
    decrement() {
      this.$store.dispatch("reduce", this.step);
    },
    incrementOdd() {
      this.$store.dispatch("addOdd", this.step);
    },
    incrementWait() {
      this.$store.dispatch("addWait", this.step);
    },
  },
};
</script>

App.vue

<template>
  <div id="app">
    <CountVuex></CountVuex>
  </div>
</template>

<script>
import CountVuex from "./components/CountVuex.vue";
export default {
  name: "App",
  components: {
    CountVuex,
  },
};
</script>

main.js

import Vue from "vue";
import App from "./App.vue";
import store from "./store";
Vue.config.productionTip = false;

new Vue({
  render: (h) => h(App),
  store,
}).$mount("#app");