Vue系列六：列表渲染

Love The Way You Lie 2022-01-30 06:15 290阅读 0赞

1.  列表显示指令  
    数组:v-for/index  
    对象:v-for/key
2.  列表的更新显示  
    删除 item  
    替换 item
3.  列表的高级处理  
    列表过滤  
    列表排序

<body>
    <div id="demo">
      <h2>测试: v-for 遍历数组</h2>
      <ul>
        <li v-for="(p, index) in persons" :key="index">
          {
       {index}}--{
       {p.name}}--{
       {p.age}}
          --<button @click="deleteP(index)">删除</button>
          --<button @click="updateP(index, {name:'Cat', age: 16})">更新</button>
        </li>
      </ul>
      <button @click="addP({name: 'xfzhang', age: 18})">添加</button>
      <h2>测试: v-for 遍历对象</h2>
      <ul>
        <li v-for="(item, key) in persons[1]" :key="key">{
       {key}}={
       {item}}</li>
      </ul>
    </div>
    <script type="text/javascript" src="../js/vue.js"></script>
    <script type="text/javascript">
      // vue本身只是监视了persons的变化，没有监视数组内部数据的变化
      // vue 重写了数组中的一系列改变数组内部数据的方法（先调用原生，更新界面）
      new Vue({
        el: '#demo',
        data: {
          persons: [ 
            {name: 'Tom', age:18},
            {name: 'Jack', age:17},
            {name: 'Bob', age:19},
            {name: 'Mary', age:16}
          ]
        },
        methods: {
          deleteP (index) {
            this.persons.splice(index, 1) // 调用了不是原生数组的splice(), 而是一个变异(重写)方法
          },
          updateP (index, newP) {
            console.log('updateP', index, newP)
            this.persons.splice(index, 1, newP)
          },
          addP (newP) {
            this.persons.push(newP)
          }
        }
      })
    </script>
    </body>

<body>
    <div id="demo">
      <input type="text" v-model="searchName">
      <ul>
        <li v-for="(p, index) in filterPersons" :key="index">
          {
       {index}}--{
       {p.name}}--{
       {p.age}}
        </li>
      </ul>
      <div>
        <button @click="setOrderType(2)">年龄升序</button>
        <button @click="setOrderType(1)">年龄降序</button>
        <button @click="setOrderType(0)">原本顺序</button>
      </div>
    </div>
    
    <script type="text/javascript" src="../js/vue.js"></script>
    <script type="text/javascript">
      new Vue({
        el: '#demo',
        data: {
          searchName: '',
          orderType: 0, // 0代表不排序, 1代表降序, 2代表升序
          persons: [
            {name: 'Tom', age:18},
            {name: 'Jack', age:17},
            {name: 'Bob', age:19},
            {name: 'Mary', age:16}
          ]
        },
    
        computed: {
          filterPersons () {
            // 取出相关数据
            const {searchName, persons, orderType} = this
            let arr = [...persons]
            // 过滤数组
            if(searchName.trim()) {
              arr = persons.filter(p => p.name.indexOf(searchName)!==-1)
            }
            // 排序
            if(orderType) {
              arr.sort(function (p1, p2) {
                if(orderType===1) { // 降序
                  return p2.age-p1.age
                } else { // 升序
                  return p1.age-p2.age
                }
    
              })
            }
            return arr
          }
        },
    
        methods: {
          setOrderType (orderType) {
            this.orderType = orderType
          }
        }
      })
    </script>
    </body>