阻止(禁止)textare回车换行

 <van-field
        v-model="form.messageCont"
        rows="3"
        label="口号"
        autosize
        type="textarea"
        placeholder="请输入口号内容(最多输入64个字)"
        maxlength="64"
        show-word-limit
        @keydown="checkEnter"
 ></van-field>

 checkEnter(e){
      var et=e||window.event;
      var keycode=et.charCode||et.keyCode;
      if(keycode==13){
         if(window.event){
             window.event.returnValue = false;
       }else{
             e.preventDefault();//for firefox
       }
    }
 },