<demo-block title="基础用法">
  <van-nav-bar
    title="标题"
    right-text="按钮"
    left-arrow
    bind:click-left="onClickLeft"
    bind:click-right="onClickRight"
  />
</demo-block>
<demo-block title="高级用法">
  <van-nav-bar title="标题" left-text="返回" left-arrow>
    <van-icon name="search" slot="right" custom-class="icon" size="18" />
  </van-nav-bar>
</demo-block>