在小程序中使用下拉菜單組件的時候，會顯示出好幾個警告：slot "" is not found (for component "miniprogram_npm/@vant/weapp/popup/index）；查看miniprogram_npm中的popup組件里面有默認slot，但是因為wx:if 初始值為false導致初始解析時跳過，所以會彈出警告，解決辦法再下面加個wx-else的默認插槽；如下：

<view
  wx:if="{{ inited }}"
  class="custom-class {{ classes }} {{ utils.bem('popup', [position, { round, safe: safeAreaInsetBottom, safeTop: safeAreaInsetTop }]) }}"
  style="{{ computed.popupStyle({ zIndex, currentDuration, display, customStyle }) }}"
  bind:transitionend="onTransitionEnd"
>
  <slot />
  <van-icon
    wx:if="{{ closeable }}"
    name="{{ closeIcon }}"
    class="close-icon-class van-popup__close-icon van-popup__close-icon--{{ closeIconPosition }}"
    bind:tap="onClickCloseIcon"
  />
</view>
//添加默認插槽
<view wx:else style="display: none;">
  <slot></slot>
</view>