小程序button背景显示图片

标签

<button class="control" open-type="share" style="background-image:url(../../resources/join_group.png)" plain="true"></button>     

对应的样式

 .control {
      position: absolute;
      bottom: 70px;
      width: 34px;
      height: 34px;
      right: 20px;
      background-size: 34px 34px;
    }        
 button.control[plain] {
      border: 0;
    }