vue中v-for循环选中点击的元素并对该元素添加样式操作

<div v-for = "(item,index) in items" :class = 'addclass:isactive' @click='onclick()'>
 <span>{{item.name}}</span>
</div>

.addclass{
 color : red;
}

data:{
 items :[
  {
  name ：'apple',
  price: '5$'
  },
  {
  name:'banana',
  price:"3$"
  },
  {
  name:'pear',
  price:'4$'
  }
 ],
 isactive : false
}

onclick(){
 this.isactive = true
}

<div v-for = "(item,index) in items" :class = "isactive == index ? 'addclass' : '' " @click='onclick(index)'>
 <span>{{item.name}}</span>
</div>

.addclass{
 color : red;
}

data:{
 items :[
  {
  name ：'apple',
  price: '5$'
  },
  {
  name:'banana',
  price:"3$"
  },
  {
  name:'pear',
  price:'4$'
  }
 ],
 isactive : -1
}
onclick(index){

 //将点击的元素的索引赋值给bian变量
 this.isactive = index
}

<template>
<!-- 点击某个绑定样式 -->
 <ul>
  <li v-for="(data, index) in formData" :key="data.id" :class="{active: isActive}" @click="currentInfo(data, index)">name: {{data.name}}，age: {{data.age}}
  </li>
 </ul>

</template>

<script>
export default {
  name: 'classActive'
  data() {
    return {
      isActive: false,  // 用来判断active样式类是否显示
      formData: [{
        id: 1,
        name: 'zhangsan',
        age: 20
      },{
        id: 2,
        name: 'lisi',
        age: 21
      },{
        id: 3,
        name: 'wangwu',
        age: 22
      }
    }
  }
  methods: {
    currentInfo(data, index) {
      if(data.id-1 === index) { // 当前选择的列表项与列表id号相等则绑定active
       this.isActive = true;
      }
    }
  }
}
</script>

<style scoped>
  li {
    list-style: none;
    border: 1px solid #333;
  }
  .active {
    background: light-gray;
  }
</style>

<template>
<!-- 点击某个绑定样式 -->
 <ul>
  <li v-for="(data, index) in formData" :key="data.id" :class="currentClass(index)" @click="currentInfo(index)">name: {{data.name}}，age: {{data.age}}
  </li>
 </ul>

</template>

<script>
export default {
  name: 'classActive'
  data() {
    return {
      currentNumber: 0,  // 用来判断active样式类是否显示
      formData: [{
        id: 1,
        name: 'zhangsan',
        age: 20
      },{
        id: 2,
        name: 'lisi',
        age: 21
      },{
        id: 3,
        name: 'wangwu',
        age: 22
      }
    }
  }
  methods: {
    currentInfo(index) {
      this.currentNumber = index;
    },
    currentClass(index) {
      return [this.currentNumber == index ? 'active' : ''];
    }
  }
}
</script>

<style scoped>
  li {
    list-style: none;
    border: 1px solid #333;
  }
  .active {
    background: light-gray;
  }
</style>