elementui table 中加下拉菜单

<el-table-column prop="roleList" label=角色 :width="180">
       <template slot-scope="scope">
           <el-select :ref="scope.row.id" multiple v-model="scope.row.roleName" @change="changeRole(scope.row)">
               <el-option v-for="item in scope.row.roleList" :label="item.name" :value="item.id" :key="item.id"></el-option>
           </el-select>
        </template>
</el-table-column>