【mpvue】radio-group 标签组设置默认选择checked: 'true'，选择了单选按钮的非默认选项，再点击其他的选择，单选按钮又会变成默认的选项

<template>
  <div class="row">
    <label class="label">基金类型：</label>  
    <radio-group class="radio-group" @change="radioChange">
      <label class="radio" v-for="(item, index) in items" :key="item.name">
        <radio color='#EA5A49' :value="item.name" :checked="item.checked"  /> {{item.value}}
      </label>
    </radio-group>
    <label class="label">手续费率：</label>
    <picker
      mode="multiSelector"
      @change="bindMultiPickerChange"
      :value="multiIndex"
      :range="multiArray"
    >
    <view class="picker">
      {{multiArray[0][multiIndex[0]]}} {{multiArray[1][multiIndex[1]]}}
    </view>
    </picker>
  </div>
</template>
<script>
  created () {
    as_type: 1
  },
  data () {
    return {
      items: [
        {name: 1, value: '场内',checked: 'true'},
        {name: 2, value: '场外'}
      ],
      multiIndex: [0,0],
      multiArray: [['万', '千'], [1, 0.5, 0.6, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5]]
    }
  }
  methods: {
    radioChange (e) {
      this.as_type = e.target.value
    }
  }
</script>

radioChange (e) {
  this.as_type = e.target.value
  if(this.as_type === '2'){
    this.items[1].checked = 'true'
  }else{
    this.items[1].checked = ''
  }
  console.log('this.as_type',this.as_type)
}