由于Vant原生的选择器组件只支持值列表的数据，而不支持键值对列表的数据，并且使用较为麻烦，于是对Vant的选择器组件进行了封装。

• 封装组件代码
   

  <template>
    <!-- 封装vant的选择器 -->
    <div>
      <van-field
        readonly
        clickable
        name="picker"
        :value="text"
        :label="label"
        :placeholder="placeholder"
        @click="showPicker = true"
      />
      <van-popup v-model="showPicker" position="bottom">
        <van-picker
          show-toolbar
          :columns="columns"
          @confirm="onConfirm"
          @cancel="showPicker = false"
        />
      </van-popup>
    </div>
  </template>
  <script>
  export default {
    props: {
      data: {
        default: null,
        type: Array
      },
      value: {
        default: "",
        type: String
      },
      label: {
        default: "选择器",
        type: String
      },
      placeholder: {
        default: "点击选择",
        type: String
      }
    },
    computed: {
      columns() {
        let values = this.data.map(item => {
          return item.value;
        });
        return values;
      }
    },
    data() {
      return {
        showPicker: false,
        text: ""
      };
    },
    methods: {
      onConfirm(value, index) {
        let key = this.data[index].key;
        this.text = value;
        this.$emit("input", key);
        this.showPicker = false;
      }
    }
  };
  </script>

• 使用方法

  <template>
    <div>
      <my-vant-pcker
        v-model="value"
        :data="data"
        label="城市选择"
        placeholder="请选择城市"
      ></my-vant-pcker>
    </div>
  </template>
  <script>
  import MyVantPcker from "@/components/MyVantPcker";
  export default {
    components: { MyVantPcker },
    data() {
      return {
        value: "",
        data: [
          {
            key: "hangzhou",
            value: "杭州"
          },
          {
            key: "shanghai",
            value: "上海"
          },
          {
            key: "beijing",
            value: "北京"
          }
        ]
      };
    }
  };
  </script>