15.vue动画& vuex

Vue.config.productionTip = false; ==是否显示提示信息==

==import/export==

export xxx 必须跟跟对象或者和定义一起

对象： export {xxxx}
定义: export let a = xxx;
export function(){}
---------------------------------

引入：

import modA from "./a" 错误
import {a} from "./a"

导出：

a.js
let a = 12;
export a;错误
export {a}

引入：

import modA from "./a" // modA => {a:12}

导出：

a.js
let a = 12;
export default {a}

导出:

export let a = "a";
等价于
let a = "a";
export {a};

引入：

import {a} from "./a"

导出:

let a = "a"
export default {a};
等价于
export default {a:"a"};

引入：

import modA from "./a";

导出

export var a = "a";
export var b = "b";
export var c = "c";

导入

import modA from "./a";错误

import * as modA from "./a";
console.log("modA",modA,modA.a,modA.b,modA.c);
或:
import {a,b,c} from "./a";
console.log("modA",a,b,c);

导出：

let a = "a";
let b = "b";
let c = "c";
export default {a,b,c}

导入

import modA from "./a";
console.log("modA",modA,modA.a,modA.b,modA.c);

==export default 导出去的东西==

==引入的时候可以取任意的名字==

++一个模块只能有一个default++

导出

export default function(){
alert("fn1");
};
export let a = 1;
export let b = 2;
export let c = 3;

引入：

import * as all from "./a";
// ==接收所有==
console.log("0modA",all,all.default,all.a,all.b,all.c);

import modA from "./a";
==//获取的default出去的东西==
console.log("1modA",modA);

import {a,b,c} from "./a";
console.log("2modA", a,b,c);

==>合并

import modA,{a,b,c} from "./a";
console.log("2modA",modA, a,b,c);

导出

export default {a:1};
export let b = "b";

引入

import modA from "./a";
console.log("2modA",modA);

setTimeout(()=>{
import("./a").then(res=>{
console.log("then:",res,res.default,res.b);
});
---------------------------------------------

sass/less/css

sass:$
less:@

sass:安装 cnpm i -S sass-loader node-sass

.sass
.scss

less:安装 cnpm i -S less-loader less

样式里面配置 lang="scss/less"

运动/动画

原生写法

两部分：进入enter、离开leave

enter ---->none-->block 显示的过程
leave ---->block-->none 消失的过程

动画原生写法

xxx-enter{}        开始的状态   
xxx-enter-active{} 运动形态     
xxx-enter-to{}     终点     

xxx-leave{}        离开的开始的状态     
xxx-leave-active{} 运动形态     
xxx-leave-to{}     离开终点

exp1:留言板一

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
<style>
#div1{width:200px; height: 200px; background: #ccc;}

.fade-enter{opacity: 0;}
.fade-enter-active{ transition: 1s all ease;}
.fade-enter-to{opacity: 1;}

.fade-leave{opacity: 1;}
.fade-leave-active{transition: 1s all ease;}
.fade-leave-to{opacity: 0;}
</style>
<script src = "vue.js"></script>
<script>
window.onload = function(){
    let vm = new Vue({
        el:"#app",
        data:{
            isShow:true,
        },
        methods:{
            showHide(){
                this.isShow = !this.isShow;
            }
        }
    })  
}
</script>
</head>
<body>
<div id="app">
    <input @click="showHide" type="button" value="显示隐藏"/>

    <transition name="fade">
        <div id="div1" v-show="isShow"></div>
    </transition>
</div>
</body>
</html>

使用自定义的动画名称

enter-class = "xxx"     
enter-active-class = "xxx"      
enter-to-class = "xxx"      

leave-class = "xxx"     
leave-active-class = "xxx"      
leave-to-class = "xxx"

exp2:留言板二

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<style>
*{marign:0;padding:0;list-style:none;}

ul{width:300px; overflow: hidden; border:1px solid green;}
ul li{ text-indent: 2em; height:50px; line-height: 50px; border-bottom: 1px dashed red;}
ul li:nth-last-child(1) { border-bottom:none;}

.fade-slide-enter{opacity:0;height: 0;}
/*.fade-slide-enter-active{ transition: 1s all ease;}*/

.fade-slide-in-active{ transition: 1s all ease;}
.fade-slide-enter-to{opacity:1;height: 50px;}

.fade-slide-leave{opacity:1;height: 50px;}
/*.fade-slide-leave-active{transition: 1s all ease;}*/
.fade-slide-out-active{transition: 1s all ease;}
.fade-slide-leave-to{opacity:0;height: 0;}

</style>
<script src="vue.js"></script>
<script>
window.onload = function(){
    let vm = new Vue({
        el:"#app",
        data:{
            msg:"abc",
            arr:["aaa","bbb","ccc"]
        },
        methods:{
            add(){
                this.arr.push(this.msg); 
            },
            /*del(index){
                 this.arr.splice(index,1)
            } */
            del(item){
                this.arr = this.arr.filter(value=>{
                    return item != value;
                });
           }
        }
    }); 
};
</script>
</head>

<body>
<div id="app">
    <input v-model="msg" type="text" value=""/>
    <input @click="add" type="button" value="添加"/>
    <ul>
        <transition-group name="fade-slide" 
            enter-active-class="fade-slide-in-active"
            leave-active-class="fade-slide-out-active"    
        >
            <li v-for="item,index in arr" :key="item">{{item}}<a @click="del(item)" href="javascript:;">删除</a></li>
        </transition-group>
    </ul>
    
</div>
</body>
</html>

运动：

transition：只能作用一个元素要多个元素需要使用 transition-group

使用animate.css：

1、animated添加到 transition标签上

<transition enter-active-class="animated xxx">
    <div>动画的元素</div>
</transition>

2、animated添加到 transition动画的元素上

<transition>
    <div class="animated"></div>
</transition>

exp3:留言板三

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<link rel="stylesheet" href="animate.css"/>
<style>
*{margin:0;padding:0;list-style:none;}

ul{width:300px; overflow: hidden; border:1px solid green;}
ul li{ text-indent: 2em; height:50px; line-height: 50px; border-bottom: 1px dashed red;}
ul li:nth-last-child(1) { border-bottom:none;}

</style>
<script src="vue.js"></script>
<script>
window.onload = function(){
    let vm = new Vue({
        el:"#app",
        data:{
            msg:"abc",
            arr:["aaa","bbb","ccc"]
        },
        methods:{
            add(){
                this.arr.push(this.msg); 
            },
            del(item){
                this.arr = this.arr.filter(value=>{
                    return item != value;
                });
           }
        }
    }); 
};
</script>
</head>

<body>
<div id="app">
    <input v-model="msg" type="text" value=""/>
    <input @click="add" type="button" value="添加"/>
    <ul>
        <transition-group 
            enter-active-class="animated rollIn"
            leave-active-class="animated rollOut"    
        >
            <li v-for="item,index in arr" :key="item">{{item}}<a @click="del(item)" href="javascript:;">删除</a></li>
        </transition-group>
    </ul>
    
</div>
</body>
</html>

==vue2-animate==

cnpm i vue2-animate

vue-cli:引入外部文件

1、index.html页面安装传统的引入文件的方式进行引入
2、在入口文件main.js 通过import 直接导入
import "vue2-animate/dist/vue2-animate";

==vuex==

Vuex 是一个专为 Vue.js 应用程序开发的状态管理模式。它采用集中式存储管理应用的所有组件的状态，并以相应的规则保证状态以一种可预测的方式发生变化

==记住一句话：如果要修改state里面的值，只能通过mutaions进行修改！！！==

https://vuex.vuejs.org/zh/guide/

https://github.com/vuejs/vuex

1、选安装

cnpm i -S vuex

2、导入

import Vuex from "vuex";

3、创建存储空间

let store = new Vuex.Store({
      strict:true,严格模式
        getters:{},
        mutations:{},
        actions:{},
        modules:{}
});

每一个 Vuex 应用的核心就是 store（仓库）。“store”基本上就是一个容器，它包含着你的应用中大部分的状态 (state)。Vuex 和单纯的全局对象有以下两点不同：

Vuex 的状态存储是响应式的。当 Vue 组件从 store 中读取状态的时候，若 store 中的状态发生变化，那么相应的组件也会相应地得到高效更新。

你不能直接改变 store 中的状态。改变 store 中的状态的唯一途径就是显式地提交 (commit) mutation。这样使得我们可以方便地跟踪每一个状态的变化，从而让我们能够实现一些工具帮助我们更好地了解我们的应用

4、==注入实例Vue==

new Vue({
    store
})

通信方式：

组件--->store

0、this.$store.state.count = xxx; 不推荐的错误方式

1、this.$store.commit("mutation",value);
2、this.$store.dispatch("action",value);

store-->store

action--->mutation

ctx.commit("mutation",value);
ctx.dispatch("action",value);

action/mutation区别

mutation只能做同步操作不能做异步！
所有数据修改只能通过mutation进行,
action不能直接修改state值

getters:简单的认为就是获取数据的一个计算属性

使用的时候不需要带括号： this.$store.getters.方法名称

exp:

import Vue from "vue";
import Vuex from "vuex";
Vue.use(Vuex);

export default new Vuex.Store({
  strict:true,
  state:{
    count:1,
  },
  getters:{
    filterCount(state){
        return state.count >= 20? "20":state.count;
    }
  },
  mutations:{//只能做同步操作 
    plusMutation(state,payload){//value  payload有效载荷 
      state.count++;
    },
    minusMutation(state,payload){//value  payload有效载荷 
        state.count--;
      }
  },
  actions:{//执行同步和异步操作 
    plusAction({commit,dispatch},payload){//ctx容器  payload有效载荷
        commit("plusMutation");
    },
    minusAction({commit},payload){
        commit("minusMutation");
    }
  }
});

模块：多人开发，命名冲突

1、模块之间的数据访问，是区分模块

this.$store.state.count

this.$store.state.modA.count

2、方法不区分模块

this.$store.commit("mutation",value);

如果要区分模块需要加上命名空间
在子模块中添加 namespaced: true,

调用子模块的方法
this.$store.commit("modA/mutation",value);

功能函数

mapState/mapGetters/mapActions/mapMutations

... 解构赋值

store.vue

<template>
<div>
  <input @click="minus" type="button" value="减"/><br />
    {{count}}------{{filterCount}} <br />
    <input @click="plus" type="button" value="加"/> 

</div>
</template>

<script>
import {mapState,mapGetters,mapActions,mapMutations} from "vuex";

console.log("mapState:",mapState({count:"count"})); 
console.log("mapGetters:",mapGetters({filterCount:"filterCount"})); 
console.log("mapActions:",mapActions({minus:"minusAction"})); 
console.log("mapMutations:",mapMutations({plus:"plusMutation"})); 

export default {
  name: "Store",
  data(){
    return{
      
    }
  }, 
  computed:{
    ...mapState({count:"count"}),
    ...mapGetters({filterCount:"filterCount"})
  },
  methods:{
    ...mapActions({minus:"minusAction"}),
    ...mapMutations({plus:"plusMutation"})
  },
}
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>

</style>

store.js


import Vue from "vue";
import Vuex from "vuex";
Vue.use(Vuex);

export default new Vuex.Store({
  strict:true,
  state:{
    count:1,
  },
  getters:{
    filterCount(state){
        return state.count >= 20? "20":state.count;
    }
  },
  mutations:{//只能做同步操作 
    plusMutation(state,payload)st{//value  payload有效载荷 
      state.count++;
    },
    minusMutation(state,payload){//value  payload有效载荷 
        state.count--;
      }
  },
  actions:{//执行同步和异步操作 
    plusAction({commit,dispatch},payload){//ctx容器  payload有效载荷
        commit("plusMutation");
    },
    minusAction({commit},payload){
        commit("minusMutation");
    }
  }
});

混入 (mixins)

mixins是一种分发 Vue 组件中可复用功能的非常灵活的方式。混入对象可以包含任意组件选项。当组件使用混入对象时，所有混入对象的选项将被混入该组件本身的选项。

<template>
<div>
  <input @click="minus" type="button" value="减"/><br />
    {{count}}------{{filterCount}} <br />
    <input @click="plus" type="button" value="加"/> 

</div>
</template>

<script>
import {mapState,mapGetters,mapActions,mapMutations} from "vuex";

console.log("mapState:",mapState({count:"count"})); 
console.log("mapGetters:",mapGetters({filterCount:"filterCount"})); 
console.log("mapActions:",mapActions({minus:"minusAction"})); 
console.log("mapMutations:",mapMutations({plus:"plusMutation"})); 

let stateMixi = {
    computed:mapState({count:"count"})
};
let gettersMixi = {
    computed:mapGetters({filterCount:"filterCount"})
};
let actionsMixi = {
    methods:mapActions({minus:"minusAction"})
};
let mutationsMixi = {
    methods:mapMutations({plus:"plusMutation"})
};


export default {
  name: "Store",
  data(){
    return{
      
    }
  },
   mixins: [stateMixi,gettersMixi,actionsMixi,mutationsMixi]
  // computed:mapGetters({filterCount:"filterCount"}),
  // methods:mapMutations({plus:"plusMutation"}),


  // computed:{
  //   // count(){
  //   //   return this.$store.state.count;
  //   // },
  //   // filterCount(){
  //   //   return this.$store.getters.filterCount;
  //   // }
  // },
  // methods:{ 
  //   plus(){
  //     //mutation
  //     this.$store.commit("plusMutation");
  //   },
  //   minus(){
  //     //action
  //     this.$store.dispatch("minusAction");
  //   },
  // }
}
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>

</style>