uniapp如何实现手动触发键盘弹出功能

<template>
  <view>
   <input type="text" placeholder="请输入用户名" @click="showKeyboard"/>
  </view>
</template>

<script>
export default {
  methods: {
    showKeyboard() {
      uni.showKeyboard({
        defaultValue: '',
        maxLength: 20,
        multiple: false,
        confirmHold: true,
        fixed: true,
        success: () => {},
        fail: () => {},
        complete: () => {}
      })
    }
  }
}
</script>