// wxml

<textarea class="textareaIpt"  bindlinechange="lineChange" style="height: {{textHeight}}rpx;" disabled="{{true}}" placeholder="请输入内容" auto-height="{{true}}" value=""></textarea>

​

// js

lineChange (event) {

  this.setData({

    textHeight: event.detail.heightRpx

  })

},

// css

.textareaIpt {

  height: auto;

  font-size: 28rpx;

  font-family: PingFangSC-Regular,

    PingFang SC;

  font-weight: 400;

  color: #555555;

  line-height: 42rpx;

  text-align: justify;

  border: 1rpx solid transparent;

  overflow-y: visible;

}