使用vantUI下拉框（弹窗）的一些bug

 <div class="item">
 上午体温
 <van-dropdown-menu class="dropdownMeau" active-color="#1989fa" close-on-click-outside>
     <van-dropdown-item v-model="formData.pmTemperature" :title="formData.pmTemperature" :options="options" />
  </van-dropdown-menu> 
  </div>

 <div  class="item">
       上午体温:
       <div class="options">
            <select v-model="formData.amTemperature"
               size="10"
               class="amTemperature"
               @change="handleChange"
               @blur="handleBlur"
               @click="handleClick"
             >
            <option v-for="(item,index) in options" :key="index" :value="item.value">{{ item.text }}</option>
            </select>
       </div>
  </div>

handleClick(){
  if(this.options.length>6){
     this.size=7
   }  
 }
handleBlur(){
   this.size=0
 }
handleChange(){
   this.size=0
 }

<van-dialog v-model="show" title="标题" show-cancel-button @click="show=true"></van-dialog> 

 <van-dropdown-menu class="dropdownMeau" active-color="#1989fa"
        :direction="direction" 
        close-on-click-outside
        @click="showPopup"
        >
           <van-popup
                v-model="show"
                closeable
                position="bottom"
                :style="{ height: '50%' }"
                 >
                     <van-dropdown-item v-model="formData.amTemperature" :title="formData.amTemperature" :options="options" />
           </van-popup>
 </van-dropdown-menu>

     handleClick() {
         let wHeight = window.innerHeight; // 获取初始可视窗口高度
         console.log(wHeight);
         window.onscroll = () => {
         // 获取当前元素距离可视区域底部的距离
        let bottomH = window.innerHeight - (this.$refs.contentRef.offsetTop - window.pageYOffset) - this.$refs.contentRef.offsetHeight
        console.log('获取当前元素距离可视区域底部的距离');
         console.log(bottomH);
         if (bottomH <= 60) {
        console.log('111');
        this.$refs.contentRef.direction = 'up'
        }
       }
     },

            <div class="item">
                    <van-field
                        readonly
                        clickable
                        label="下午温度"
                        :value="formData.pmTemperature"
                        :placeholder="formData.pmTemperature"
                        @click="showPicker = true"
                    />
                    <van-popup v-model="showPicker" round position="bottom">
                        <van-picker
                            show-toolbar
                            :columns="options"
                            @cancel="showPicker = false"
                            @confirm="onPmConfirm"
                        />
                    </van-popup>
                </div>

methods: {
        onPmConfirm(value) {
            this.formData.pmTemperature = value;
            this.showPicker = false;
        }
    }