vue-ant-design select-启用showSearch后，autoFocus和focus（）方法不会使输入集中

Question

使用vue-ant-design select呈现可搜索的select下拉列表

从文档中，我编写了以下组件

<template>
  <a-select
    showSearch
    placeholder="Select a person"
    optionFilterProp="children"
    style="width: 200px"
    @focus="handleFocus"
    @blur="handleBlur"
    @change="handleChange"
    :filterOption="filterOption"
  >
    <a-select-option value="jack">Jack</a-select-option>
    <a-select-option value="lucy">Lucy</a-select-option>
    <a-select-option value="tom">Tom</a-select-option>
  </a-select>
</template>
<script>
  export default {
    methods: {
      handleChange(value) {
        console.log(`selected ${value}`);
      },
      handleBlur() {
        console.log('blur');
      },
      handleFocus() {
        console.log('focus');
      },
      filterOption(input, option) {
        return (
          option.componentOptions.children[0].text.toLowerCase().indexOf(input.toLowerCase()) >= 0
        );
      },
    },
  };
</script>

选择选项后，焦点无法工作。该如何解决？