elementui中label标签添加自定义图标

<template>
  <div class="hello">
    <el-form>
      <el-row>
        <el-col :span="5">
          <div class="grid-content bg-purple">
            <el-form-item label-width="120px">
              <span slot="label">
                <span class="span-box">
                  <span>主食 ：</span>
                  <i class="el-icon-tableware ico-pre"></i>
                </span>
              </span>
              <el-radio v-model="radio" label="1">饺子</el-radio>
              <el-radio v-model="radio" label="2">米饭</el-radio>
            </el-form-item>
          </div>
        </el-col>
      </el-row>
      <el-row>
        <el-col :span="5">
          <div class="grid-content bg-purple">
            <el-form-item label-width="120px">
              <span slot="label">
                <span class="span-box">
                  <span>喜欢的配菜 ：</span>
                  <i class="el-icon-dish-1 ico-pre"></i>
                </span>
              </span>
              <el-radio v-model="radio1" label="3">千页豆腐</el-radio>
              <el-radio v-model="radio1" label="4">空心菜</el-radio>
            </el-form-item>
          </div>
        </el-col>
      </el-row>
    </el-form>
  </div>
</template>

<script>


export default {
  name: 'HelloWorld',
  props: {
    msg: String
  },
  data () {
      return {
        radio: '1',
        radio1:'4'
      };
    }
}
</script>

<style scoped>
.span-box{
  display:inline-block;
  position:relative;
}
.ico-pre{
  position:absolute;
  left:-21px;
  top:12px;
}
</style>

　　效果图