navigationBar如何设置左上角的返回按钮

便签无效，用函数替代：

  <view class='row lr-padding flex-row' bindtap='goToList'>
    <view class='icon' data-icon='discount'></view>
    <view class='title t3-color'>优惠券</view>
    <view class='sub-title t6-color text-r over-ell'>{{wxUserInfo.couponCount}}张</view>
    <view class='arrow'></view>
  </view>

js

/**
     * 进入列表
     */
    goToList: function () {
        wx.navigateTo({
            url: '/pages/mine/coupon/coupon',
        })
    },

20180313170601265.png