实现效果：
======2015/5/11======
优化滚动条(scroll)：默认的滚动条太丑，忍不住优化下
优化前：
优化后：
CORE CODE:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Talk Room</title>
<style type="text/css"> *{
margin: 0;
padding: 0;
} li{
list-style: none;
} body{
font-family: "microsoft yahei";
background-color: #f7f7f7;
color: #666;
font-size: 13px;
line-height: 1.8em;
} .roomArea{
width: 400px;
height: 500px;
background-color: #fff;
border-radius: 3px;
box-shadow: 0 1px 2px rgba(0,0,0,.3);
position: absolute;
top:0;
right: 0;
bottom: 0;
left: 0;
margin: auto;
} .room-content{
width: 100%;
height: 320px;
overflow-y:auto;
border-bottom: 1px solid #f7f7f7;
} .opArea{
width: 100%;
} .wordsInput{
width: 380px;
padding: 10px;
height: 80px;
margin-bottom: 20px;
border: 0;
outline: 0;
border-bottom: 1px solid #f7f7f7;
font-family: "microsoft yahei";
} .btn{
float: right;
margin:0 6px;
padding: 5px 20px;
border: 0;
outline: 0;
border-radius: 3px;
background-color: #eb4f38;
color: #fff;
border: 1px solid transparent;
} #offBtn{
background-color: #a9b7b7;
} .inp{
width: 125px;
outline: 0;
height: 25px;
border: 0;
border-bottom: 1px solid #f7f7f7;
} label{
margin-left: 10px;
} .msg-list{
position: relative;
} .msg-list li{
display:inline-block;
padding: 6px 0;
margin: 6px 0;
} .words {
position: relative;
display: inline-block;
margin-left: 60px;
background-color: #00bb9c;
color: #fff;
padding: 5px 8px;
border-radius: 4px;
width: 240px;
min-height: 40px;
} .words:before{
content: '';
position: absolute;
top:7px;
left:-6px;
border-style: solid;
border-width: 6px 12px 6px 0;
border-color: transparent #00bb9c transparent transparent;
} .nickName {
position: absolute;
left: 10px;
width: 40px;
height: 40px;
border-radius: 20px;
background-color: #00bb9c;
display: inline-block;
line-height: 40px;
text-align: center;
color: #fff;
-webkit-box-shadow: 0 0 1px rgba(0,0,0,.3);
box-shadow: 0 0 1px rgba(0,0,0,.3);
} .time {
float: right;
font-size: 12px;
color: #eee;
} .oRight .nickName {
position: absolute;
right: 10px;
left: auto;
background-color: #56abe4;
} .oRight .words{
background-color: #56abe4;
} .oRight .words:before{
display: none;
} .oRight .words:after{
content: '';
position: absolute;
top:7px;
right:-6px;
border-style: solid;
border-width: 6px 0 6px 12px ;
border-color: transparent transparent transparent #56abe4 ; } </style> </head>
<body> <div class="roomArea"> <div class="room-content" >
<ul class="msg-list" id="msgList">
</ul>
</div> <div class="opArea"> <textarea class="wordsInput" id="txtInput" placeholder="说点什么吧"></textarea>
<label for="inp">输入昵称:</label>
<input type="text" class="inp" id="inp">
<button class="btn" id="offBtn">取消</button>
<button class="btn" id="sendBtn">发布</button> </div> </div> <!--js部分--> <script type="text/javascript"> var oMsgList=document.getElementById('msgList');
var oTxtInput=document.getElementById('txtInput');
var oInp=document.getElementById('inp');
var oOffBtn=document.getElementById('offBtn');
var oSendBtn=document.getElementById('sendBtn');
var lastUserName = "";
oSendBtn.onclick=function addWords(){ if (oTxtInput.value=='') {
alert('输入内容不能为空');
oTxtInput.focus();
return false;
} else if (oInp.value=='') {
alert('昵称不能为空');
oInp.focus();
return false;
} else{
oMsgList.innerHTML+="<li>"+"<span class='nickName'>"+oInp.value +"</span>" + "<span class='words'>"+oTxtInput.value+"<span class='time'>"+getTime()+"</span>"+"</span>" +"</li>"; //遍历li
var i=""; var li_arr=document.getElementsByTagName('li');
// //获取tag名为li的html元素 if (li_arr.length > 1) {
if (lastUserName === oInp.value) {
li_arr[li_arr.length -1].className = li_arr[li_arr.length -2].className;
} if (!li_arr[li_arr.length -2].classList.contains('oRight') && lastUserName !== oInp.value) {
li_arr[li_arr.length -1].classList.add('oRight');
}
} lastUserName = oInp.value;
oInp.value='';
oTxtInput.value=''; } } function getTime(){
var date = new Date();
var year = date.getFullYear();
var month = date.getMonth()+1;
var day = date.getDate();
var hours = date.getHours();
var minutes = date.getMinutes();
var seconds = date.getSeconds();
var time = year+'/'+month+'/'+day+' '+hours+':'+minutes+':'+seconds;
return time;
} </script> </body>
</html>