vue element-ui el-transfer 获取选中值

 templete
 <el-transfer
      filterable
      @left-check-change="leftCopeChane"
      :titles="['菜品', '已选菜品']"
      :filter-method="filterMethod"
      v-model="value"
      :props="{
        key: 'id',
        label: 'name'
       }"
      :data="dataList">
      <span slot-scope="{option}">{{option.name}}
        <span style="float: right;padding-right:10px;font-size: 10px;text-align: left">
          {{option.typeName==null?'':';'+option.typeName}}
          {{option.tasteName==null?'':';'+option.tasteName}}
          {{option.feelName==null?'':';'+option.feelName}}
          {{option.spicyName==null?'':';'+option.spicyName}}
        </span>
      </span>
    </el-transfer>

method:
    leftCopeChane(selecedOption) {
        if (selecedOption.length > this.selecedOption.length) {
          let selectValue = selecedOption.concat(this.selecedOption).filter(v => !selecedOption.includes(v) || !this.selecedOption.includes(v))
          alert(selecedOption + ' ' + this.selecedOption + '选中' + selectValue);
        }
        this.selecedOption = selecedOption;
      },

selectValue极为选中的值