JavaScript实现QQ聊天消息展示和评论提交功能

时间:2020-05-15 清风明月000 人气:0

QQ聊天消息显示，提交评论等实现原理，具体内容如下

<!DOCTYPE html>
<html>
 <head>
  <meta charset="UTF-8">
  <title></title>

  <style type="text/css">
   * {
    margin: 0;
    padding: 0;
   }

   .bos {
    margin: 100px auto;
    width: 350px;
    position: relative;
   }

   .bos a {
    float: right;
   }

   button {
    position: relative;
    left: 301px;
    bottom: 0;
   }

   textarea {
    width: 350px;
    resize: none;
   }

   ul li {
    list-style: none;
   }
  </style>

  <script type="text/javascript">
   window.onload = function() {
    var txt = document.getElementById('txt');
    var btn = document.getElementsByTagName('button')[0];
    var oUl = document.getElementsByTagName('ul')[0];

    btn.onclick = function() {
     if(txt.value == '') {
      alert('请输入...');
      return false; //结束事件*******
     }

     var newli = document.createElement('li');  //创建标签<li></li>
     newli.innerHTML = txt.value + '<a href = "#">删除<a>';

     //oUl.appendChild(newli);  //将创建标签<li></li>加到最后面

     var lis = oUl.childNodes; //oUl.children
     oUl.insertBefore(newli, lis[0]);  //将创建标签<li></li>加到最前面
     txt.value = '';


     //删除发出去的消息
     var oA = document.getElementsByTagName('a');
     for(var i = 0; i < oA.length; i++) {
      oA[i].onclick = function() {
       oUl.removeChild(this.parentNode);
      }
     }
    }
   }
  </script>

 </head>

 <body>
  <div id="box" class="bos">
   <textarea name="" id="txt" cols="30" rows="10"></textarea>
   <button>submit</button>
   <ul></ul>
  </div>
 </body>

</html>

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