小程序实现textarea随输入的文字行数变化高度自动增加

<view class="text-box">
      <text>{{currentInput}}</text>
      <textarea class="weui-textarea" placeholder="请输入文本" bindinput="getInput" maxlength="1000"/>
</view>

.text-box{
   width:100%; 
   position: relative;
   min-height:80rpx;
}
.text-box text{
  display:block;
  visibility:hidden;
  overflow-y: hidden; 

}
.text-box .weui-textarea{
    height:100%;
    position: absolute;
    overflow-y: hidden;
   left:0;
   top:0;
}

Page({
  data: {
    currentInput:‘‘
  },
  getInput:function(e){
    this.setData({
      currentInput: e.detail.value
    })
  }
})