1 　<view>
 2     <view class="tit-main">
 3       请补充详细问题和意见
 4       <text class="tit-deputy currentWordNumber">(必填，{{currentWordNumber|0}}/{{max}})</text>
 5     </view>
 6     <view class="idea">
 7       <textarea name="bindTextAreaBlur" bindinput="getValueLength" show-confirm-bar=‘true‘ maxlength="{{max}}">   
 8       </textarea>
 9     </view>
10 　</view>

 1 data: {
 2     max: 300,
 3     param: {
 4       content: ‘‘
 5     }
 6   },
 7 getValueLength: function(e) {
 8     let _this = this
 9     let value = e.detail.value
10     let len = parseInt(value.length)
11     var param = this.data.param;
12     param.content = value
13     if (len > _this.data.max) return;
14     this.setData({
15       currentWordNumber: len,
16       param: param
17     })
18   }