微信小程序 button样式设置为图片的方法

<button open-type='share' class="share" style="background-image:url(https://example./imgs/icon_2_forward@2x.png);" plain='true'>
</button>

.goBack .share{
 width: 38rpx;
 height: 36rpx;
 padding:0 20rpx;
 position: absolute;
 right: 32rpx;
 : 0;
 bottom: 0;
 margin: auto;
 background-size: 38rpx 36rpx;
 background-repeat:no-repeat;
 border:none;
}

 <button class="btn">
<image src="/images/img.png">
</image>
</button>

<view class="df_1 l_h15">
 <contact-button size="22" class='pos'></contact-button>
  <image class="icon_kf" src="/images/kefu.png"></image> 
 <view class="dbtext">客服</view>
 </view>

.pos{
 position: absolute;
 : 10px;
 left: 23px;
 opacity: 0;
}
.icon_kf{
 width: 20px;
 height: 20px;
 display: inline-block;
 margin-: 5px;
}
.dbtext{
 line-height: 15px;
 color: #666;
 font-size: 12px;
}
//狼蚁网站SEO优化是最外层的view的样式，可以要也可以不要
.df_1{
-webkit-box-flex: 1;
-webkit-flex: 1;
-ms-flex: 1;
flex: 1;
-webkit-tap-highlight-color: transparent;
}
.l_h15{
 line-height: 15px;
 text-align: center;
}