3，v-if的使用 

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Document</title>
  <style>
    .red1 {
      color: red;
    }
    .tabUl {
      display: flex;
      list-style: none;
    }
    .tabUl li {
      margin: 0 20px 0 0;
    }
    .show1 {
      color: blue;
      cursor: pointer;
    }
  </style>

</head>

<body>
  <div id="app">
    <p>v-if 和计算属性</p>
    <h5 v-if="score >=90">优秀</h5>
    <h5 v-else-if="score >=80">良好</h5>
    <h5 v-else>不及格</h5>

    <!-- 使用计算属性写法 -->
    <div>{{result}}</div>

    <!-- 登入切换 -->
    <div class="login">
      <ul class="tabUl">
        <li @click="tabsClick(0)">账号</li>
        <li @click="tabsClick(1)">邮箱</li>
      </ul>
      <div class="login11" v-show="isUser ==0">
        <label for="username">用户账号：</label>
        <input type="text" id="username" placeholder="请输入用户账号" key="username" />
      </div>
      <div class="login11" v-show="isUser ==1">
        <label for="email">用户邮箱：</label>
        <input type="text" id="email" placeholder="请输入用户邮箱" key="email" />
      </div>
    </div>

  </div>
</body>
<script src="vue.js"></script>
<script>
  new Vue({
    el: '#app',
    data: {
      score: 85,
      isUser: 0,
    },
    computed: {
      result() {
        let showMessage = '';
        if (this.score >= 90) {
          showMessage = '优秀'
        } else if (this.score >= 80) {
          showMessage = '良好'
        } else {
          showMessage = '不及格'
        }
      }

    },
    created: function () {},
    methods: {
      tabsClick(index) {
        this.isUser = index;

      }
    }
  })
</script>

</html>

 

 
 
posted @ 2021-05-10 20:55  云悠  阅读(97)  评论(0)    收藏  举报