[JavaScript知识库]vue记事本

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?1.在vuex创建一个数组存放数据，以及点击添加/删除的方法

import Vue from 'vue'
import Vuex from 'vuex'

Vue.use(Vuex)

export default new Vuex.Store({
  state: {
    list:[]
  },
  mutations: {
  	//添加数据
    setAdd(state,data){
      state.list.push(data)
    },
    //删除数据
    setDelete(state,index){
      state.list.splice(index,1)
    },
    //数据
    allall(state){
      state.list=[]
    }
  },
  actions: {
  },
  modules: {
  }
})

样式

<template>
  <div>
    <h1>todos</h1>
    <div class="home">
      <div class="h-head">
        <div class="arrow" @click="qx"></div>
        <input text="text" v-model="input" placeholder="What needs to be done?" @keydown.enter="add">
      </div>
      <div class="h-body">
        <ul class="todo-list">
					<li class="todo" :class="{'completed':item.state}" v-for="item,index in showList" :key="index">
						<div class="view">
							<!-- 通过多选框 改变 finished的状态 -->
							<input class="toggle" type="checkbox" v-model="item.state"/>
							<!-- 当点击文字时 实现反选 -->
							<label @click="item.state==!item.state">{{item.title}}---{{item.state}}</label>
							<button class="destroy" @click="setDelete(index)"></button>
						</div>
					</li>
				</ul>

        <div class="footer"  v-cloak v-show="list.length>0">
          <span class="todo-count"> <strong>{{num}} </strong>{{num | numFilter}} left </span>
          <ul class="filters">
             <li>
              <a href="#" @click="cli=0" :class="{'selected':cli==0 || ''}">All</a>
            </li>
            <li>
              <a href="#" @click="cli=1" :class="{'selected':cli==1}">Active</a>
            </li>
            <li>
              <a href="#" @click="cli=2" :class="{'selected':cli==2}">Completed</a>
            </li>
          </ul>
          <button class="clear-completed" @click="allall">Clear completed</button>
        </div>
      </div>
    </div>
    <footer class="info">
			<p>Double-click to edit a todo</p>
			<p>Written by <a href="http://evanyou.me">Evan You</a></p>
			<p>Part of <a href="http://todomvc.com">TodoMVC</a></p>
		</footer>
  </div>
</template>

html,body{
	margin: 0px;
	padding: 0px;
}
body{
	background-color: #f5f5f5;
}
h1{
	font-size: 99px;
    color: #e8d9d8;
    margin: 0 0;
	text-align: center;
}
.home{
	width: 500px;
	height: auto;
	background: #fff;
	margin: 0 auto;
	box-shadow: 0px 0px 4px 2px #ccc;
}
.h-head{
	width: 100%;
	height: 50px;
	position: relative;
}
.h-head .arrow{
	width: 40px;
    height: 50px;
    position: absolute;
    top: -11px;
    left: 0px;
    transform: rotate(90deg);
}
.h-head .arrow::before{
	content: '?';
    font-size: 22px;
    color: #e6e6e6;
    padding: 10px 27px 10px 27px;
}
.h-head input{
	width: 88%;
    height: 44px;
    margin-left: 51px;
    display: #fff;
    border: none;
    outline: none;
    font-size: 21px;
}
.h-head input::-webkit-input-placeholder{
	color:#e6e6e6;
}
.h-body{
	width: 100%;
	height: auto;
	position: relative;
}
.h-b-todo{
	width: 100%;
	height: 50px;
	background: blue;
}
.multipleChoice{
	width: 30px;
	height: 30px;
	border-radius: 50%;
}
.todo-list {
	margin: 0;
	padding: 0;
	list-style: none;
}

.todo-list li {
	position: relative;
	font-size: 24px;
	border-bottom: 1px solid #ededed;
	border: 1px solid #ccc;
	border-bottom: none;
}

.todo-list li:last-child {
	border-bottom: none;
}

.todo-list li.editing {
	border-bottom: none;
	padding: 0;
}

.todo-list li.editing .edit {
	display: block;
	width: calc(100% - 43px);
	padding: 12px 16px;
	margin: 0 0 0 43px;
}

.todo-list li.editing .view {
	display: none;
}

.todo-list li .toggle {
	text-align: center;
	width: 40px;
	/* auto, since non-WebKit browsers doesn't support input styling */
	height: auto;
	position: absolute;
	top: 0;
	bottom: 0;
    left: 0;
	margin: auto 0;
	border: none; /* Mobile Safari */
	-webkit-appearance: none;
	appearance: none;
}

.todo-list li .toggle {
	opacity: 0;
}

.todo-list li .toggle + label {
	/*
		Firefox requires `#` to be escaped - https://bugzilla.mozilla.org/show_bug.cgi?id=922433
		IE and Edge requires *everything* to be escaped to render, so we do that instead of just the `#` - https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/7157459/
	*/
	background-image: url('data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20width%3D%2240%22%20height%3D%2240%22%20viewBox%3D%22-10%20-18%20100%20135%22%3E%3Ccircle%20cx%3D%2250%22%20cy%3D%2250%22%20r%3D%2250%22%20fill%3D%22none%22%20stroke%3D%22%23ededed%22%20stroke-width%3D%223%22/%3E%3C/svg%3E');
	background-repeat: no-repeat;
	background-position: center left;
}

.todo-list li .toggle:checked + label {
    text-align: left;
	background-image: url('data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20width%3D%2240%22%20height%3D%2240%22%20viewBox%3D%22-10%20-18%20100%20135%22%3E%3Ccircle%20cx%3D%2250%22%20cy%3D%2250%22%20r%3D%2250%22%20fill%3D%22none%22%20stroke%3D%22%23bddad5%22%20stroke-width%3D%223%22/%3E%3Cpath%20fill%3D%22%235dc2af%22%20d%3D%22M72%2025L42%2071%2027%2056l-4%204%2020%2020%2034-52z%22/%3E%3C/svg%3E');
}

.todo-list li label {
	word-break: break-all;
	padding: 15px 15px 15px 60px;
	display: block;
	line-height: 1.2;
	transition: color 0.4s;
    text-align: left;
}

.todo-list li.completed label {
	color: #d9d9d9;
	text-decoration: line-through;
    text-align: left;
}

.todo-list li .destroy {
	display: none;
	position: absolute;
	top: 0;
	right: 10px;
	bottom: 0;
	width: 40px;
	height: 40px;
	margin: auto 0;
	font-size: 30px;
	color: #cc9a9a;
	margin-bottom: 11px;
	transition: color 0.2s ease-out;
	border: none;
	background-color: #fff;
}

.todo-list li .destroy:hover {
	color: #af5b5e;
}

.todo-list li .destroy:after {
	content: '×';
}

.todo-list li:hover .destroy {
	display: block;
}

.todo-list li .edit {
	display: none;
}

.todo-list li.editing:last-child {
	margin-bottom: -1px;
}
.footer {
	color: #777;
	padding: 10px 15px;
	height: 20px;
	text-align: center;
	border-top: 1px solid #e6e6e6;
    height: 50px;
}

.footer:before {
	content: '';
	position: absolute;
	right: 0;
	bottom: 0;
	left: 0;
	height: 50px;
	overflow: hidden;
	box-shadow: 0 1px 1px rgba(0, 0, 0, 0.2),
	            0 8px 0 -3px #f6f6f6,
	            0 9px 1px -3px rgba(0, 0, 0, 0.2),
	            0 16px 0 -6px #f6f6f6,
	            0 17px 2px -6px rgba(0, 0, 0, 0.2);
}

.todo-count {
	float: left;
	text-align: left;
}

.todo-count strong {
	font-weight: 300;
}

.filters {
	margin: 0;
	padding: 0;
	list-style: none;
	position: absolute;
	right: 0;
	left: 0;
}

.filters li {
	display: inline;
}

.filters li a {
	color: inherit;
	margin: 3px;
	padding: 3px 7px;
	text-decoration: none;
	border: 1px solid transparent;
	border-radius: 3px;
}

.filters li a:hover {
	border-color: rgba(175, 47, 47, 0.1);
}

.filters li a.selected {
	background: blueviolet;
	color: #fff;
}

.clear-completed,
html .clear-completed:active {
	float: right;
	position: relative;
	line-height: 20px;
	text-decoration: none;
	cursor: pointer;
}

.clear-completed:hover {
	text-decoration: underline;
}

.info {
	margin: 65px auto 0;
	color: #bfbfbf;
	font-size: 10px;
	text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
	text-align: center;
}

.info p {
	line-height: 1;
}

.info a {
	color: inherit;
	text-decoration: none;
	font-weight: 400;
}

.info a:hover {
	text-decoration: underline;
}
@media screen and (-webkit-min-device-pixel-ratio:0) {
	.toggle-all,
	.todo-list li .toggle {
		background: none;
	}

	.todo-list li .toggle {
		height: 40px;
	}
}

@media (max-width: 430px) {
	.footer {
		height: 50px;
	}

	.filters {
		bottom: 10px;
	}
}

2.在页面中调用方法，且传入数据(具体内容已经写在字里行间，笔者不做过多解释)

<script>
import {mapState,mapMutations} from 'vuex'
export default {
  name: 'Home',
  data(){
    return {
      input:'',//获取input的值
      cli:0//默认为展示所有项
    }
  },
  computed:{
    ...mapState(['list']),//调用值
    num(){
      return this.list.filter(item=>!item.state).length//返回数组长度
    },
    showList(){
    	//点击筛选
      switch(this.cli) {
        case 0://展示所有
          return this.list;
        case 1://过滤掉不被选择的
          return this.list.filter(item=>!item.state);
        default://过滤掉不被选择的
          return this.list.filter(item=>item.state);
      }
    }
  },
  filters:{
  	//当勾选的事情超过一件，则item加s
    numFilter(value){
      return value==1?'item':'items'
    }
  },
  methods:{
  	//调用方法
    ...mapMutations(['setAdd','setDelete','allall']),
    add(){
    	//当点击回车键之后，添加相对应的数据
      this.setAdd({
        id:new Date().getTime(),//id不重复
        title:this.input,//input的值
        state:false//状态最开始为false
      })
      this.input = ''//当当前数据添加完之后，清空input里面的值
    },
    qx(){
    	//点击input前面的箭头，执行反选
      this.showList.map(item=>{
        switch(item.state){
          case true:
            return item.state = false
          default:
            return item.state = true
        }
      })
    }
  }
}
</script>

注意：当input的值为空时，不能再添加值，那么此时我们需要做一个判断，当值为空时，禁用回车键，也就是当ascii值为13时，禁止添加。

深夜码字辛苦，相互加油吧。晚安！