vant自定义引入iconfont图标及字体的方法步骤

import './assets/css/common/iconfont.css'

<div>
   <i class="iconfont wticon-riqi"></i>
</div>

import './assets/js/iconfont.js'

    <div>
     //黑白色的图标
      <i class="iconfont wticon-riqi"></i>
     //彩色的图标
     //svg下的class名是iconfont，use下的class名是#+图标名
      <svg class="iconfont">
         <use xlink:href="#wticon-riqi" rel="external nofollow" ></use>
      </svg>
    </div>

<van-form @submit="onSubmit">
      <van-field
        v-model="username"
        left-icon="smile-o"
        name="用户名"
        placeholder="用户名"
        :rules="[{ required: true, message: '请填写手机号' }]"
      />
      <van-field
        v-model="password"
        name="密码"
        placeholder="密码"
        :rules="[{ required: true, message: '请填写验证码' }]"
      />
      <div style="margin: 16px">
        <van-button block type="info" native-type="submit">提交</van-button>
      </div>
    </van-form>

<van-form @submit="onSubmit">
      <van-field
        v-model="username"
        left-icon="smile-o"
        name="用户名"
        placeholder="用户名"
        :rules="[{ required: true, message: '请填写手机号' }]"
      >
      <i slot="left-icon" class="toutiao toutiao-shouji"></i>
      </van-field>
      <van-field
        v-model="password"
        name="密码"
        placeholder="密码"
        :rules="[{ required: true, message: '请填写验证码' }]"
      >
      <i slot="left-icon" class="toutiao toutiao-jiesuo"></i>
      </van-field>
      <div style="margin: 16px">
        <van-button block type="info" native-type="submit">提交</van-button>
      </div>
    </van-form>