html代码:
<script src="../js/jquery.min.js"></script>
<!--评论内容框--> <div id="toWrite" style="display: none"> <textarea class="toWrite1" rows="10" id="toWrite1"></textarea> <input id="postBt" type="button" value="发布" @click="post"/> </div>
<div id="notNull" style="display: none">留言不能为空!!</div>
css代码:
#notNull{ position: absolute; left:33%; top:45%; width:2.78rem; height:0.7rem; color:red; border-radius:2px; background-color: #B3B3B3; line-height: 0.7rem; text-align: center; font-size: 0.3rem; z-index: 96; }
javascript代码:
var content=document.getElementById("toWrite1").value; //判断留言内容是否为空 function isNull( str ){ if ( str == "" ) return true; var regu = "^[ ]+$"; var re = new RegExp(regu); return re.test(str); } var result=isNull(content); //console.log(result); if(content.toString().length==0||content==" "||result==true){ $("#notNull").show(); setTimeout(function(){$("#notNull").hide();},3000);//3秒后执行该方法 return; }